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Conservation_of_mass | The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy , the mass of the system must remain constant over time , as system mass can not change quantity if it is not added or removed . Hence , the quantity of mass is `` conserved '' over time . The law implies that mass can neither be created nor destroyed , although it may be rearranged in space , or the entities associated with it may be changed in form , as for example when light or physical work is transformed into particles that contribute the same mass to the system as the light or work had contributed . Thus , during any chemical reaction , nuclear reaction , or radioactive decay in an isolated system , the total mass of the reactants or starting materials must be equal to the mass of the products . The concept of mass conservation is widely used in many fields such as chemistry , mechanics , and fluid dynamics . Historically , mass conservation was discovered in chemical reactions by Antoine Lavoisier in the late 18th century , and was of crucial importance in the progress from alchemy to the modern natural science of chemistry . The closely related concept of matter conservation was found to hold good in chemistry to such high approximation that it failed only for the high energies treated by the later refinements of relativity theory , but otherwise remains useful and sufficiently accurate for most chemical calculations , even in modern practice . In special relativity , needed for accuracy when large energy transfers between systems is involved , the difference between thermodynamically closed and isolated systems becomes important , since conservation of mass is strictly and perfectly upheld only for so-called isolated systems , i.e. those completely isolated from all exchanges with the environment . In this circumstance , the mass -- energy equivalence theorem states that mass conservation is equivalent to total energy conservation , which is the first law of thermodynamics . By contrast , for a thermodynamically closed system ( i.e. , one which is closed to exchanges of matter , but open to exchanges of non-material energy , such as heat and work , with the surroundings ) mass is ( usually ) only approximately conserved . The input or output of non-material energy must change the mass of the system in relativity theory , although the change is usually small , since relatively large amounts of such energy ( by comparison with ordinary experience ) carry only a small amount of mass ( again by ordinary standards of measurement ) . In special relativity , mass is not converted to energy , since mass and energy can not be destroyed , and energy in all of its forms always retains its equivalent amount of mass throughout any transformation to a different type of energy within a system ( or translocation into or out of a system ) . Certain types of matter ( a different concept ) may be created or destroyed , but in all of these processes , the energy and mass associated with such matter remains unchanged in quantity ( although type of energy associated with the matter may change form ) . In general relativity , mass ( and energy ) conservation in expanding volumes of space is a complex concept , subject to different definitions , and neither mass nor energy is as strictly and simply conserved as is the case in special relativity and in Minkowski space . For a discussion , see mass in general relativity . |
Comparison_(grammar) | Comparison is a feature in the morphology or syntax of some languages , whereby adjectives and adverbs are inflected or modified to indicate the relative degree of the property defined by the adjective or adverb . The comparative expresses a comparison between two ( or more ) entities or groups of entities in quality , quantity , or degree ; the superlative is the form of an adverb or adjective that is the greatest degree of a given descriptor . The grammatical category associated with comparison of adjectives and adverbs is degree of comparison . The usual degrees of comparison are the positive , which simply denotes a property ( as with the English words big and fully ) ; the comparative , which indicates greater degree ( as bigger and more fully ) ; and the superlative , which indicates greatest degree ( as biggest and most fully ) . Some languages have forms indicating a very large degree of a particular quality ( called elative in Semitic linguistics ) . Other languages ( e.g. English ) can express lesser degree , e.g. beautiful , less beautiful , least beautiful . The comparative is frequently associated with adjectives and adverbs because these words take the - er suffix or modifying word more or less ( e.g. , faster , more intelligent , less wasteful ) ; it can also , however , appear when no adjective or adverb is present , for instance with nouns ( e.g. , more men than women ) . One preposition , near , also has a superlative form , as in Find the restaurant nearest your house . |
Climate_risk | Climate risk means a risk resulting from climate change and affecting natural and human systems and regions . In the course of increasing global temperature and extreme weather phenomena the Intergovernmental Panel on Climate Change ( IPCC ) has been founded by the United Nations Environment Programme ( UNEP ) and the World Meteorological Organization ( WMO ) for a better understanding of climate change and meeting concerns of these observations . Its main aim is evaluating climate risks and exploring strategies for the prevention of these risks . |
Climate | Climate is the statistics of weather , usually over a 30-year interval . It is measured by assessing the patterns of variation in temperature , humidity , atmospheric pressure , wind , precipitation , atmospheric particle count and other meteorological variables in a given region over long periods of time . Climate differs from weather , in that weather only describes the short-term conditions of these variables in a given region . A region 's climate is generated by the climate system , which has five components : atmosphere , hydrosphere , cryosphere , lithosphere , and biosphere . The climate of a location is affected by its latitude , terrain , and altitude , as well as nearby water bodies and their currents . Climates can be classified according to the average and the typical ranges of different variables , most commonly temperature and precipitation . The most commonly used classification scheme was the Köppen climate classification . The Thornthwaite system , in use since 1948 , incorporates evapotranspiration along with temperature and precipitation information and is used in studying biological diversity and how climate change affects it . The Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region . Paleoclimatology is the study of ancient climates . Since direct observations of climate are not available before the 19th century , paleoclimates are inferred from proxy variables that include non-biotic evidence such as sediments found in lake beds and ice cores , and biotic evidence such as tree rings and coral . Climate models are mathematical models of past , present and future climates . Climate change may occur over long and short timescales from a variety of factors ; recent warming is discussed in global warming . Global warming results in redistributions . For example , `` a 3 ° C change in mean annual temperature corresponds to a shift in isotherms of approximately 300 -- 400 km in latitude ( in the temperate zone ) or 500 m in elevation . Therefore , species are expected to move upwards in elevation or towards the poles in latitude in response to shifting climate zones '' . |
Coal | Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams . The harder forms , such as anthracite coal , can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure . Coal is composed primarily of carbon , along with variable quantities of other elements , chiefly hydrogen , sulfur , oxygen , and nitrogen . A fossil fuel , coal forms when dead plant matter is converted into peat , which in turn is converted into lignite , then sub-bituminous coal , after that bituminous coal , and lastly anthracite . This involves biological and geological processes that take place over time . Throughout human history , coal has been used as an energy resource , primarily burned for the production of electricity and heat , and is also used for industrial purposes , such as refining metals . Coal is the largest source of energy for the generation of electricity worldwide , as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases . The extraction of coal , its use in energy production and its byproducts are all associated with environmental and health effects including climate change . Coal is extracted from the ground by coal mining . Since 1983 , the world 's top coal producer has been China . In 2015 China produced 3,747 million tonnes of coal -- 47.7 % of 7,861 million tonnes world coal production . In 2015 other large producers were United States ( 813 million tonnes ) , India ( 678 ) , European Union ( 539 ) and Australia ( 503 ) . In 2010 the largest exporters were Australia with 328 million tonnes ( 27.1 % of world coal export ) and Indonesia with 316 million tonnes ( 26.1 % ) , while the largest importers were Japan with 207 million tonnes ( 17.5 % of world coal import ) , China with 195 million tonnes ( 16.6 % ) and South Korea with 126 million tonnes ( 10.7 % ) . |
Concentrated_solar_power | Concentrated solar power ( also called concentrating solar power , concentrated solar thermal , and CSP ) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight , or solar thermal energy , onto a small area . Electricity is generated when the concentrated light is converted to heat , which drives a heat engine ( usually a steam turbine ) connected to an electrical power generator or powers a thermochemical reaction ( experimental ) . Heat storage in molten salts allows some solar thermal plants to continue to generate after sunset and adds value to such systems when compared to photovoltaic panels . CSP is being commercialized and the CSP market saw about 740 megawatt ( MW ) of generating capacity added between 2007 and the end of 2010 . More than half of this ( about 478 MW ) was installed during 2010 , bringing the global total to 1095 MW . Spain added 400 MW in 2010 , taking the global lead with a total of 632 MW , while the US ended the year with 509 MW after adding 78 MW , including two fossil -- CSP hybrid plants . The Middle East is also ramping up their plans to install CSP based projects . Shams-I has been installed in Abu Dhabi , by Masdar . The largest CSP projects in the world is Ivanpah Solar Power Facility in the United States ( which uses solar power tower technology ) and Mojave Solar Project ( which uses parabolic troughs ) . As of January 2014 , Spain had a total capacity of 2,300 MW making this country the world leader in CSP . United States follows with 1,740 MW . Interest is also notable in North Africa and the Middle East , as well as India and China . In Italy , a handful of companies are trying to get authorization for 14 plants , totalling 392 MW , despite a strong local and political opposition . The global market has been dominated by parabolic-trough plants , which account for 90 % of CSP plants . In most cases , CSP technologies currently can not compete on price with photovoltaics ( solar panels ) , which have experienced huge growth in recent years due to falling prices of the panels and much smaller operating costs . However , the Chile Copiapó reached cents 6.3 / kWh . In 2015 , CSP represented less than 2 % of worldwide installed capacity of solar electricity plants . CSP is not to be confused with concentrator photovoltaics ( CPV ) . In CPV , the concentrated sunlight is converted directly to electricity via the photovoltaic effect . |
Climate_change_in_the_United_States | Because of global warming , there has been concern in the United States and internationally , that the country should reduce total greenhouse gas which is relatively high per capita . In 2012 , the United States experienced its warmest year on record . , the thirteen warmest years for the entire planet have all occurred since 1998 , transcending those from 1880 . From 1950 to 2009 , the American government 's surface temperature record shows an increase by 1 F-change , approximately . Global warming has caused many changes in the U.S. . According to a 2009 statement by the National Oceanic and Atmospheric Administration ( NOAA ) , trends include lake and river ice melting earlier in the spring , plants blooming earlier , multiple animal species shifting their habitat ranges northward , and reductions in the size of glaciers . Predicting future climate changes are fraught with difficulty . Some research has warned against possible problems due to American climate changes such as the spread of invasive species and possibilities of floods as well as droughts . Changes in climate in the regions of the United States appear significant . Drought conditions appear to be worsening in the southwest while improving in the northeast for example . President Barack Obama committed in the December 2009 Copenhagen Climate Change Summit to reduce carbon dioxide emissions in the range of 17 % below 2005 levels by 2020 , 42 % below 2005 levels by 2030 , and 83 % below 2005 levels by 2050 . In an address towards the U.S. Congress in June 2013 , Obama detailed a specific action plan to achieve the 17 % carbon emissions cut from 2005 by 2020 . He included such measures as shifting from coal-based power generation to solar and natural gas production . Climate change is seen as a national security threat to the United States . In 2015 , according to The New York Times and others , oil companies knew that burning oil and gas could cause global warming since the 1970s but , nonetheless , funded deniers for years . 2016 was an historic year for billion-dollar weather and climate disasters in U.S. |
Cockenzie_power_station | Cockenzie power station was a coal-fired power station in East Lothian , Scotland . It was situated on the south shore of the Firth of Forth , near the town of Cockenzie and Port Seton , 8 mi east of the Scottish capital of Edinburgh . The station dominated the local coastline with its distinctive twin chimneys from 1967 until the chimneys ' demolition in September 2015 . Initially operated by the nationalised South of Scotland Electricity Board , it was operated by Scottish Power following the privatisation of the industry in 1991 . In 2005 a WWF report named Cockenzie as the UK 's least carbon-efficient power station , in terms of carbon dioxide released per unit of energy generated . The 1,200 megawatt power station ceased generating energy on 15 March 2013 around 8.30 am . the main station is being dismantled by Brown and Mason Ltd , a UK-based demolition company . There are plans to replace the station with a Combined Cycle Gas Turbine ( CCGT ) power station . The removal of the power station was done in stages with the iconic twin chimneys and the turbine hall of the power station being demolished in a controlled explosion on 26 September 2015 , the front section of the boiler house being demolished on 4 November 2015 and finally the rest of the boiler house being demolished on 17 December 2015 . This was the last remaining major structure to be removed . |
Climate_change_in_Europe | Climate change in Europe describes the climate change related issues in Europe . This includes the climate politics , contribution in the global warming and the influence of the global warming in Europe . According to international climate experts global temperature rise should not exceed 2 ° C to prevent the most dangerous consequences of the climate change . It is estimated to demand at least 80-85 % emission reductions in the EU during 2008-2050 with reductions as soon as technically possible . It is estimated that from the now living persons alive are 70 % in the year 2050 . Emission reduction means development and implementation of new energy technology solutions . Some people consider that the technology revolution has already started in Europe since the markets of the renewable technology have annually grown . European Union climate chief is Connie Hedegaard since 10 February 2010 . |
Cold_drop | The cold drop ( gota fría ) is a weather phenomenon often occurring in the Spanish autumn . It is experienced particularly along the western Mediterranean and as such , most frequently affects the east coast of Spain . It is a closed upper-level low which has become completely displaced ( cut off ) from basic westerly current , and moves independently of that current . Cutoff lows may remain nearly stationary for days , or on occasion may move westward opposite to the prevailing flow aloft ( i.e. , retrogression ) . The term is also used to describe the meteorological phenomenon associated . In Spain , it appears when a front of very cold polar air , a jet stream , advances slowly over Western Europe , at high altitude ( normally 5 -- 9 km or 3 -- 5.5 mi ) . |
Climate_inertia | Climate inertia describes the widespread inherent characteristic of the climate , ecological , and socio-economic systems . Inertia from anthropogenic impacts may be slow to become apparent , or could be irreversible if climate change crosses associated thresholds . Melting ice sheets in Greenland and Antarctica take time to respond to the emissions of fossil fuel carbon in the climate system . The global warming also causes thermal inertia , thermal expansion of the oceans , which contributes to sea level rise . It has been estimated that we are already committed to a sea-level rise of approximately 2.3 meters for each degree of temperature rise within the next 2,000 years . |
Climate_pattern | A climate pattern is any recurring characteristic of the climate . Climate patterns can last tens of thousands of years , like the glacial and interglacial periods within ice ages , or repeat each year , like monsoons . A climate pattern may come in the form of a regular cycle , like the diurnal cycle or the seasonal cycle ; a quasi periodic event , like El Niño ; or a highly irregular event , such as a volcanic winter . The regular cycles are generally well understood and may be removed by normalization . For example , graphs which show trends of temperature change will usually have the effects of seasonal variation removed . |
Committee_on_Climate_Change_Science_and_Technology_Integration | The Committee on Climate Change Science and Technology Integration was created as part of the Clear Skies Initiative in February 2002 by George W. Bush , as a Cabinet-level effort to coordinate climate change science and technology research . The White House says : `` The Secretary of Commerce and Secretary of Energy will lead the effort , in close coordination with the President 's Science Advisor . The research effort will continue to be coordinated through the National Science and Technology Council in accordance with the Global Change Research Act of 1990 . '' |
Clean_Air_Act_(United_States) | The Clean Air Act is a United States federal law designed to control air pollution on a national level . It is one of the United States ' first and most influential modern environmental laws , and one of the most comprehensive air quality laws in the world . As with many other major U.S. federal environmental statutes , it is administered by the U.S. Environmental Protection Agency ( EPA ) , in coordination with state , local , and tribal governments . Its implementing regulations are codified at 40 C.F.R. Subchapter C , Parts 50-97 . The 1955 Air Pollution Control Act was the first U.S federal legislation that pertained to air pollution ; it also provided funds for federal government research of air pollution . The first federal legislation to actually pertain to `` controlling '' air pollution was the Clean Air Act of 1963 . The 1963 act accomplished this by establishing a federal program within the U.S. Public Health Service and authorizing research into techniques for monitoring and controlling air pollution . In 1967 , the Air Quality Act enabled the federal government to increase its activities to investigate enforcing interstate air pollution transport , and , for the first time , to perform far-reaching ambient monitoring studies and stationary source inspections . The 1967 act also authorized expanded studies of air pollutant emission inventories , ambient monitoring techniques , and control techniques . Major amendments to the law , requiring regulatory controls for air pollution , passed in 1970 , 1977 and 1990 . The 1970 amendments greatly expanded the federal mandate , requiring comprehensive federal and state regulations for both stationary ( industrial ) pollution sources and mobile sources . It also significantly expanded federal enforcement . Also , the Environmental Protection Agency was established on December 2 , 1970 for the purpose of consolidating pertinent federal research , monitoring , standard-setting and enforcement activities into one agency that ensures environmental protection . The 1990 amendments addressed acid rain , ozone depletion , and toxic air pollution , established a national permits program for stationary sources , and increased enforcement authority . The amendments also established new auto gasoline reformulation requirements , set Reid vapor pressure ( RVP ) standards to control evaporative emissions from gasoline , and mandated new gasoline formulations sold from May to September in many states . Reviewing his tenure as EPA Administrator under President George H. Bush , William K. Reilly characterized passage of the 1990 Clean Air Act as his most notable accomplishment . The Clean Air Act was the first major environmental law in the United States to include a provision for citizen suits . Numerous state and local governments have enacted similar legislation , either implementing federal programs or filling in locally important gaps in federal programs . |
Climate_change_in_Texas | Over the next century , climate in Texas could experience additional changes . For example , based on projections made by the Intergovernmental Panel on Climate Change and results from the United Kingdom Hadley Centre 's climate model ( HadCM2 ) , a model that accounts for both greenhouse gases and aerosols , by 2100 temperatures in Texas could increase by about 3 ° F ( ~ 1.7 ° C ) in spring ( with a range of 1-6 ° F ) and about 4 ° F ( ~ 2.2 ° C ) in other seasons ( with a range of 1-9 ° F ) . Precipitation is estimated to decrease by 5-30 % in winter and increase by about 10 % in the other seasons . Increases in summer could be slightly larger ( up to 30 % ) than in spring and fall . Other climate models may show different results . The amount of precipitation on extreme wet or snowy days in winter is likely to decrease , and the amount of precipitation on extreme wet days in summer is likely to increase . The frequency of extreme hot days in summer would increase because of the general warming trend . It is not clear how severe storms such as hurricanes would change . |
Circumstellar_habitable_zone | In astronomy and astrobiology , the circumstellar habitable zone ( CHZ ) , or simply the habitable zone , is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure . The bounds of the CHZ are based on Earth 's position in the Solar System and the amount of radiant energy it receives from the Sun . Due to the importance of liquid water to Earth 's biosphere , the nature of the CHZ and the objects within it may be instrumental in determining the scope and distribution of Earth-like extraterrestrial life and intelligence . The habitable zone is also called the Goldilocks zone , a metaphor of the children 's fairy tale of `` Goldilocks and the Three Bears '' , in which a little girl chooses from sets of three items , ignoring the ones that are too extreme ( large or small , hot or cold , etc. ) , and settling on the one in the middle , which is `` just right '' . Since the concept was first presented in 1953 , many stars have been confirmed to possess a CHZ planet , including some systems that consist of multiple CHZ planets . Most such planets , being super-Earths or gas giants , are more massive than Earth , because such planets are easier to detect . On November 4 , 2013 , astronomers reported , based on Kepler data , that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs in the Milky Way . 11 billion of these may be orbiting Sun-like stars . Proxima Centauri b , located about 4.2 light-years ( 1.3 parsecs ) from Earth in the constellation of Centaurus , is the nearest known exoplanet , and is orbiting in the habitable zone of its star . The CHZ is also of particular interest to the emerging field of habitability of natural satellites , because planetary-mass moons in the CHZ might outnumber planets . In subsequent decades , the CHZ concept began to be challenged as a primary criterion for life , so the concept is still evolving . Since the discovery of evidence for extraterrestrial liquid water , substantial quantities of it are now thought to occur outside the circumstellar habitable zone . The concept of deep biospheres , like Earth 's , that exist independently of stellar energy , are now generally accepted in astrobiology given the large amount of liquid water known to exist within in lithospheres and asthenospheres of the Solar System . Sustained by other energy sources , such as tidal heating or radioactive decay or pressurized by non-atmospheric means , liquid water may be found even on rogue planets , or their moons . Liquid water can also exist at a wider range of temperatures and pressures as a solution , for example with sodium chlorides in seawater on Earth , chlorides and sulphates on equatorial Mars , or ammoniates , due to its different colligative properties . In addition , other circumstellar zones , where non-water solvents favorable to hypothetical life based on alternative biochemistries could exist in liquid form at the surface , have been proposed . |
Concrete_slab | A concrete slab is a common structural element of modern buildings . Horizontal slabs of steel reinforced concrete , typically between 4 and 20 inches ( 100 and 500 millimeters ) thick , are most often used to construct floors and ceilings , while thinner slabs are also used for exterior paving . Sometimes these thinner slabs , ranging from 2 in to 6 in thick , are called mud slabs , particularly when used under the main floor slabs or in crawl spaces . In many domestic and industrial buildings a thick concrete slab , supported on foundations or directly on the subsoil , is used to construct the ground floor of a building . These can either be `` ground-bearing '' or `` suspended '' slabs . In high rise buildings and skyscrapers , thinner , pre-cast concrete slabs are slung between the steel frames to form the floors and ceilings on each level . On the technical drawings , reinforced concrete slabs are often abbreviated to `` r.c.c.slab '' or simply `` r.c. '' |
Climate_of_Chile | The climate of Chile comprises a wide range of weather conditions across a large geographic scale , extending across 38 degrees in latitude , making generalizations difficult . According to the Köppen system , Chile within its borders hosts at least seven major climatic subtypes , ranging from low desert in the north , to alpine tundra and glaciers in the east and southeast , humid subtropical in Easter Island , Oceanic in the south and Mediterranean climate in central Chile . There are four seasons in most of the country : summer ( December to February ) , autumn ( March to May ) , winter ( June to August ) , and spring ( September to November ) . On a synoptic scale , the most important factors that controls the climate in Chile are the Pacific Anticyclone , the southern circumpolar low pressure area , the cold Humboldt current , the Chilean Coast Range and the Andes Mountains . Despite Chile 's narrowness , some interior regions may experience wide temperature oscillations and cities such as San Pedro de Atacama , may even experience a continental climate . In the extreme northeast and southeast the border of Chile extends beyond the Andes into the Altiplano and the Patagonian plains , giving these regions climate patterns similar to those seen in Bolivia and Argentina respectively . |
Climate_change_opinion_by_country | Climate change opinion is the aggregate of public opinion held by the adult population . Cost constraints often restrict surveys to sample only one or two countries from each continent or focus on only one region . Because of differences among questions , wording , and methods -- it is difficult to reliably compare results or to generalize them to opinions held worldwide . In 2007 -- 2008 , the Gallup Poll surveyed individuals from 128 countries in the first comprehensive study of global opinions . The Gallup Organization aggregated opinion from the adult population fifteen years of age and older , either through the telephone or personal interviews , and in both rural and urban areas except in areas where the safety of interviewer was threatened and in scarcely populated islands . Personal interviews were stratified by population size or geography and cluster sampling was achieved through one or more stages . Although error bounds vary , they were all below ± 6 % with 95 % confidence . Weighting countries to a 2008 World Bank population estimate , sixty-one percent of individuals worldwide were aware of global warming , developed countries more aware than developing , with Africa the least aware . The median of people perceiving it as a threat was 47 % . Latin America and developed countries in Asia led the belief that climate change was a result of human activities , while Africa , parts of Asia and the Middle East , and countries from the Former Soviet Union led in the opposite . Awareness often translates to concern , although of those aware , individuals in Europe and developed countries in Asia perceived global warming as a greater threat than others . |
Colorado_Springs,_Colorado | Colorado Springs is a home rule municipality that is the county seat and the most populous municipality of El Paso County , Colorado , United States . Colorado Springs is located in the east central portion of the state . It is situated on Fountain Creek and is located 60 mi south of the Colorado State Capitol in Denver . At 6035 ft the city stands over 1 mi above sea level , though some areas of the city are significantly higher and lower . Colorado Springs is situated near the base of one of the most famous American mountains , Pikes Peak , rising above 14000 ft on the eastern edge of the Southern Rocky Mountains . The city is home to 24 national governing bodies of sport , the United States Olympic Committee and the United States Olympic Training Center . The city had an estimated population of 456,568 in 2015 , ranking as the second most populous city in the state of Colorado , behind Denver , and the 40th most populous city in the United States . The Colorado Springs , CO Metropolitan Statistical Area had an estimated population of 712,327 in 2016 . The city is included in the Front Range Urban Corridor , an oblong region of urban population along the Front Range of the Rocky Mountains in Colorado and Wyoming , generally following the path of Interstate 25 in both states . The city covers 194.9 sqmi , making it the most extensive municipality in Colorado . Colorado Springs was ranked number five by U.S. News & World Report on the list of 2016 Best Places to Live in the USA . |
Climate_of_Argentina | The climate of Argentina is a complex subject : the vast size of the country and considerable variation in altitude make for a wide range of climate types . Argentina has four seasons : winter ( June -- August ) , spring ( September -- November ) , summer ( December -- February ) and autumn ( March -- May ) , all featuring different weather conditions . Summers are the warmest and wettest season in most of the country except in most of Patagonia where it is the driest season . Winters are normally mild in the north , cool in the center and cold in the southern parts with the latter experiencing frequent frost and snow . Because southern parts of the country are moderated by the surrounding oceans , the cold is less intense and prolonged than areas at comparable latitudes in the northern hemisphere . Spring and autumn are transition seasons that generally feature mild weather . Many regions have different , often contrasting , microclimates . In general , northern parts of the country are characterized by hot , humid , rainy summers and mild winters with periodic droughts . Mesopotamia , in the northeast is characterized by high temperatures and abundant precipitation throughout the year with droughts being uncommon . West of this lies the Chaco region , which is the warmest region in Argentina . Precipitation in the Chaco region decreases westwards , resulting in the vegetation changing from forests in the east to shrubs in the west . Northwest Argentina is predominantly dry and hot although the rugged topography makes it climatically diverse , ranging from the cold , dry Puna to thick jungles . The center of the country , which includes the Pampas to the east and the drier Cuyo region to the west has hot summers with occasional tornadoes and thunderstorms , and cool , dry winters . Patagonia , in the southern parts of the country has a dry climate with warm summers and cold winters characterized by strong winds throughout the year and one of the strongest precipitation gradients in the world . High elevations at all latitudes experience cooler conditions , and the mountainous zones can see heavy snowfall . The geographic and geomorphic characteristics of Argentina tend to create extreme weather conditions , often leading to natural disasters that negatively impact the country both economically and socially . The Pampas , where many of the large cities are located , has a flat topography and poor water drainage , making it vulnerable to flooding . Severe storms can lead to tornados , damaging hail , storm surges , and high winds , causing extensive damage to houses and infrastructure , displacing thousands of people and causing significant loss of life . Extreme temperature events such as heat waves and cold waves impact rural and urban areas by negatively impacting agriculture , one of the main economic activities of the country , and by increasing energy demand , which can lead to energy shortages . Argentina is vulnerable and will likely be significantly impacted by climate change . Temperatures have increased in the last century while the observed changes in precipitation are variable , with some areas receiving more and other areas less . These changes have impacted river flow , increased the frequency of extreme weather events , and led to the retreat of glaciers . Based on the projections for both precipitation and temperatures , these climatic events are likely to increase in severity and create new problems associated with climate change in the country . |
Climate_state | Climate state describes a state of climate on Earth and similar terrestrial planets based on a thermal energy budget , such as the greenhouse or icehouse climate state . The main climate state change is between periodical glacial and interglacial cycles in Earth history , studied from climate proxies . The climate system is responding to the current climate forcing and adjusts following climate sensitivity to reach a climate equilibrium , Earth 's energy balance . Model simulations suggest that the current interglacial climate state will continue for at least another 100,000 years , due to emissions - including complete deglaciation of the Northern Hemisphere . |
Climate_of_India | The climate of India comprises a wide range of weather conditions across a vast geographic scale and varied topography , making generalisations difficult . Based on the Köppen system , India hosts six major climatic subtypes , ranging from arid desert in the west , alpine tundra and glaciers in the north , and humid tropical regions supporting rainforests in the southwest and the island territories . Many regions have starkly different microclimates . The nation has four seasons : winter ( December , January and February ) , summer ( March , April and May ) , a monsoon rainy season ( June to September ) , and a post-monsoon period ( October to November ) . India 's geography and geology are climatically pivotal : the Thar Desert in the northwest and the Himalayas in the north work in tandem to effect a culturally and economically important monsoonal regime . As Earth 's highest and most massive mountain range , the Himalayas bar the influx of frigid katabatic winds from the icy Tibetan Plateau and northerly Central Asia . Most of North India is thus kept warm or is only mildly chilly or cold during winter ; the same thermal dam keeps most regions in India hot in summer . Though the Tropic of Cancer -- the boundary between the tropics and subtropics -- passes through the middle of India , the bulk of the country can be regarded as climatically tropical . As in much of the tropics , monsoonal and other weather patterns in India can be wildly unstable : epochal droughts , floods , cyclones , and other natural disasters are sporadic , but have displaced or ended millions of human lives . There is one scientific opinion which states that in South Asia such climatic events are likely to change in unpredictability , frequency , and severity . Ongoing and future vegetative changes and current sea level rises and the attendant inundation of India 's low-lying coastal areas are other impacts , current or predicted , that are attributable to global warming . |
Climate_of_Australia | Australia 's climate is governed largely by its size and by the hot , sinking air of the subtropical high pressure belt . This moves north and south with the seasons , so that the rainfall pattern over Australia is highly seasonal . Australia 's rainfall is the lowest of all continents except Antarctica . But it is variable , with frequent droughts lasting several seasons -- thought to be caused in part by the El Niño-Southern Oscillation . The climate varies widely due to its large geographical size , but by far the largest part of Australia is desert or semi-arid . Only the south-east and south-west corners have a temperate climate and moderately fertile soil . The northern part of the country has a tropical climate , varied between tropical rainforests , grasslands and part dessert . Because Australia is a small continent , separated from polar regions by the Southern Ocean , it is not subject to the movements of frigid polar air that sweep over Northern Hemisphere continents during winter . Consequently , its winter is relatively mild , so that there is n't the great contrast between summer and winter temperatures there is in the northern continents . Yet in many parts of the country , seasonal highs and lows can be considerable : temperatures have ranged from above 50 C to well below zero . Nonetheless , minimum temperatures are moderated . The El Niño-Southern Oscillation is associated with seasonal abnormality in many areas in the world . Australia is one of the continents most affected and experiences extensive droughts alongside considerable wet periods . Occasionally a dust storm will blanket a region and there are reports of the occasional tornado . Tropical cyclones , heat waves , bushfires and frosts in the country are also associated with the Southern Oscillation . Rising levels of salinity and desertification in some areas is ravaging the landscape . Climate change in Australia is a highly contentious issue . Temperatures in the country have risen following an increasing trend of global warming between the years of 1910 to 2004 by approximately 0.7 ° C. Overnight minimum temperatures have warmed more rapidly than daytime maximum temperatures in recent years . The late-20th century warming has been largely attributed to the increased greenhouse effect . According to the Bureau of Meteorology , 80 % of the land has less than 600 mm of rainfall per year and 50 % has even less than 300 mm . As a whole , Australia has a very low annual average rainfall of 419 mm . |
Collider_Detector_at_Fermilab | The Collider Detector at Fermilab ( CDF ) experimental collaboration studies high energy particle collisions at the Tevatron , the world 's former highest-energy particle accelerator . The goal is to discover the identity and properties of the particles that make up the universe and to understand the forces and interactions between those particles . CDF is an international collaboration of about 600 physicists ( from about 30 American universities and National laboratories and about 30 groups from universities and national laboratories from Italy , Japan , UK , Canada , Germany , Spain , Russia , Finland , France , Taiwan , Korea , and Switzerland ) . The CDF detector itself weighs 5000 tons , is about 12 meters in all three dimensions . The goal of the experiment is to measure exceptional events out of the billions of collisions in order to : Look for evidence for phenomena beyond the Standard Model of particle physics Measure and study the production and decay of heavy particles such as the Top and Bottom Quarks , and the W and Z bosons Measure and study the production of high-energy particle jets and photons Study other phenomena such as diffraction The Tevatron collides protons and antiprotons at a center-of-mass energy of about 2 TeV . The very high energy available for these collisions makes it possible to produce heavy particles such as the Top quark and the W and Z bosons , which weigh much more than a proton ( or antiproton ) . These heavier particles are identified through their characteristic decays . The CDF apparatus records the trajectories and energies of electrons , photons and light hadrons . Neutrinos do not register in the apparatus leading to an apparent missing energy . Other hypothetical particles might leave a missing energy signature , and some searches for new phenomena are based on that . There is another experiment similar to CDF called D0 located at another point on the Tevatron ring . |
Cliché | A cliché or cliche ( -LSB- ˈkliːʃeɪ -RSB- or -LSB- klɪˈʃeɪ -RSB- ) is an expression , idea , or element of an artistic work which has become overused to the point of losing its original meaning or effect , even to the point of being trite or irritating , especially when at some earlier time it was considered meaningful or novel . In phraseology , the term has taken on a more technical meaning , referring to an expression imposed by conventionalized linguistic usage . The term is frequently used in modern culture for an action or idea that is expected or predictable , based on a prior event . Typically pejorative , `` clichés '' may or may not be true . Some are stereotypes , but some are simply truisms and facts . Clichés often are employed for comic effect , typically in fiction . Most phrases now considered clichéd originally were regarded as striking , but have lost their force through overuse . The French poet Gérard de Nerval once said , `` The first man who compared woman to a rose was a poet , the second , an imbecile . '' A cliché is often a vivid depiction of an abstraction that relies upon analogy or exaggeration for effect , often drawn from everyday experience . Used sparingly , it may succeed , but the use of a cliché in writing , speech , or argument is generally considered a mark of inexperience or a lack of originality . |
Conservation_agriculture | Conservation agriculture ( CA ) can be defined by a statement given by the Food and Agricultural Organization of the United Nations as `` a concept for resource-saving agricultural crop production that strives to achieve acceptable profits together with high and sustained production levels while concurrently conserving the environment '' ( FAO 2007 ) . Agriculture according to the New Standard Encyclopedia is `` one of the most important sectors in the economies of most nations '' ( New Standard 1992 ) . At the same time conservation is the use of resources in a manner that safely maintains a resource that can be used by humans . Conservation has become critical because the global population has increased over the years and more food needs to be produced every year ( New Standard 1992 ) . Sometimes referred to as `` agricultural environmental management '' , conservation agriculture may be sanctioned and funded through conservation programs promulgated through agricultural legislation , such as the U.S. Farm Bill . |
Circular_economy | A circular economy is a regenerative system in which resource input and waste , emission , and energy leakage are minimised by slowing , closing , and narrowing material and energy loops . This can be achieved through long-lasting design , maintenance , repair , reuse , remanufacturing , refurbishing , and recycling . This is contrast to a linear economy which is a ` take , make , dispose ' model of production . |
Cognition | Cognition is `` the mental action or process of acquiring knowledge and understanding through thought , experience , and the senses . '' It encompasses processes such as knowledge , attention , memory and working memory , judgment and evaluation , reasoning and `` computation '' , problem solving and decision making , comprehension and production of language , etc. . Human cognition is conscious and unconscious , concrete or abstract , as well as intuitive ( like knowledge of a language ) and conceptual ( like a model of a language ) . Cognitive processes use existing knowledge and generate new knowledge . The processes are analyzed from different perspectives within different contexts , notably in the fields of linguistics , anesthesia , neuroscience , psychiatry , psychology , education , philosophy , anthropology , biology , systemics , logic , and computer science . These and other different approaches to the analysis of cognition are synthesised in the developing field of cognitive science , a progressively autonomous academic discipline . Within psychology and philosophy , the concept of cognition is closely related to abstract concepts such as mind and intelligence . It encompasses the mental functions , mental processes ( thoughts ) , and states of intelligent entities ( humans , collaborative groups , human organizations , highly autonomous machines , and artificial intelligences ) . Thus , the term 's usage varies across disciplines ; for example , in psychology and cognitive science , `` cognition '' usually refers to an information processing view of an individual 's psychological functions . It is also used in a branch of social psychology called social cognition to explain attitudes , attribution , and group dynamics . In cognitive psychology and cognitive engineering , cognition is typically assumed to be information processing in a participant 's or operator 's mind or brain . Cognition can in some specific and abstract sense also be artificial . The term `` cognition '' is often incorrectly used to mean `` cognitive abilities '' or `` cognitive skills . '' |
Climatology | Climatology ( from Greek κλίμα , klima , `` place , zone '' ; and - λογία , - logia ) or climate science is the study of climate , scientifically defined as weather conditions averaged over a period of time . This modern field of study is regarded as a branch of the atmospheric sciences and a subfield of physical geography , which is one of the Earth sciences . Climatology now includes aspects of oceanography and biogeochemistry . Basic knowledge of climate can be used within shorter term weather forecasting using analog techniques such as the El Niño -- Southern Oscillation ( ENSO ) , the Madden -- Julian oscillation ( MJO ) , the North Atlantic oscillation ( NAO ) , the Northern Annular Mode ( NAM ) which is also known as the Arctic oscillation ( AO ) , the Northern Pacific ( NP ) Index , the Pacific decadal oscillation ( PDO ) , and the Interdecadal Pacific Oscillation ( IPO ) . Climate models are used for a variety of purposes from study of the dynamics of the weather and climate system to projections of future climate . Weather is known as the condition of the atmosphere over a period of time . While Climate has to do with the atmospheric condition over an extended to indefinite period of time . |
Convention_on_Early_Notification_of_a_Nuclear_Accident | The Convention on Early Notification of a Nuclear Accident is a 1986 International Atomic Energy Agency ( IAEA ) treaty whereby states have agreed to provide notification of any nuclear accident that occur within its jurisdiction that could affect other states . It , along with the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency , was adopted in direct response to the April 1986 Chernobyl disaster . By agreeing to the Convention , a state acknowledges that when any nuclear or radiation accident occurs within its territory that has the potential of affecting another state , it will promptly notify the IAEA and the other states that could be affected . The information to be reported includes the incident 's time , location , and the suspected amount of radioactivity release . The Convention was concluded and signed at a special session of the IAEA general conference on 26 September 1986 ; the special session was called because of the Chernobyl disaster , which had occurred five months before . Significantly , the Soviet Union and the Ukrainian SSR -- the states that were responsible for the Chernobyl disaster -- both signed the treaty at the conference and quickly ratified it . It was signed by 69 states and the Convention entered into force on 27 October 1986 after the third ratification . As of 2015 , 119 state parties have ratified the Convention ; the European Atomic Energy Community , the Food and Agriculture Organization , the World Health Organization , and the World Meteorological Organization have also entered into the Convention . The states that have ratified the Convention but have since denounced it and withdrawn from the agreement are Bulgaria , Hungary , Mongolia , and Poland . The states that have signed the Convention but not ratified it are Bahamas , Côte d'Ivoire , Democratic Republic of the Congo , Holy See , Niger , North Korea , Sierra Leone , Sudan , Syria , and Zimbabwe . |
Cross-State_Air_Pollution_Rule | The Cross-State Air Pollution Rule ( CSAPR ) is a ruling by the United States Environmental Protection Agency ( EPA ) that requires member states of the United States to reduce power plant emissions that contribute to ozone and/or fine particle pollution in other states . The EPA describes this rule as one that `` protects the health of millions of Americans by helping states reduce air pollution and attain clean air standards . '' |
Culture_of_California | The culture of California is tied to the culture of the United States as a whole . However , there are features that are unique to California . With roots in the cultures of Spain , Asia , Mexico , and the eastern United States , California integrates foods , languages and traditions from all over the world . Spain had explored the present state of California since the 16th century , although it did not colonize it and exert its cultural influence in earnest until the 18th century . By the 19th century , Spain had built missions throughout all the state and Californios owned huge land extensions ( called `` ranchos '' ) . From that time to the present , Hispanic Californians have always been among the largest cultural groups in the state . Furthermore , Mexican immigration into California has also resulted in a large share of cultural contributions . California culture has also been greatly influenced by several other large immigrant populations , especially those from Latin America and East Asia . California is a true melting pot as well as an international gateway to the United States . California has long been a subject of interest in the public mind and has often been promoted by its boosters as a kind of paradise . In the early 20th Century , fueled by the efforts of state and local boosters , many Americans saw the Golden State as an ideal resort destination , sunny and dry all year round with easy access to the ocean , deserts and mountains . In the 1960s , popular music groups such as The Beach Boys promoted the image of Californians as laid-back , tanned beach-goers . In terms of socio-cultural mores and national politics , Californians are perceived as more liberal than most other Americans , especially those who live in the inland states . The state , in whole , is perceived as liberal , though the northern region is seen as more liberal than the southern region , and the coast is seen as more liberal than the inland regions . California is also home to many prestigious universities including Stanford University , the California Institute of Technology , the University of California , the University of Southern California and the Claremont Colleges . The California Gold Rush of the 1850s is still seen as a symbol of California 's modern economic style , a pioneering spirit that tends to generate technology , social ventures , entertainment , and economic fads and booms that , in many cases , are followed all around the globe . The hippie movement began in San Francisco , California , in the early 1960s and progressed into the late 1970s . |
Crop | A crop is any plant , macroscopic fungus , or alga cultivated in agriculture or aquaculture ( algaculture ) . Most crops are harvested as food for humans or livestock ( fodder crops ) . Important non-food crops ( industrial crops ) are produced for clothing ( fiber crops ) , biofuel ( energy crops , algae fuel ) , or medicine ( medicinal plants ) . The word crop may refer either to all harvested parts of a plant or to the harvest in a more refined state ( husked , shelled , etc. ) . Animals and microbes ( fungi , bacteria or viruses ) are only rarely referred to as crops . Animals raised for human or animal consumption are referred to as livestock and microbes as microbiological cultures . Microbes are not typically grown for food itself , but are rather used to alter food ( e.g. , generating citric acid , fermenting yogurt , soy sauce , or sauerkraut ) . |
Coupled_model_intercomparison_project | In climatology , the Coupled Model Intercomparison Project ( CMIP ) is a framework and the analog of the Atmospheric Model Intercomparison Project ( AMIP ) for global coupled ocean-atmosphere general circulation models ( GCMs ) . CMIP began in 1995 under the auspices of the Working Group on Coupled Modeling ( WGCM ) , which is in turn under auspices of CLIVAR and the Joint Scientific Committee for the World Climate Research Program . The Program for Climate Model Diagnosis and Intercomparison at Lawrence Livermore National Laboratory supports CMIP by helping WGCM to determine the scope of the project , by maintaining the project 's data base and by participating in data analysis . CMIP has received model output from the pre-industrial climate simulations ( `` control runs '' ) and 1 % per year increasing-CO2 simulations of about 30 coupled GCMs . More recent phases of the project ( 20C3M , ... ) include more realistic scenarios of climate forcing for both historical , paleoclimate and future scenarios . |
Convective_instability | In meteorology , convective instability or stability of an air mass refers to its ability to resist vertical motion . A stable atmosphere makes vertical movement difficult , and small vertical disturbances dampen out and disappear . In an unstable atmosphere , vertical air movements ( such as in orographic lifting , where an air mass is displaced upwards as it is blown by wind up the rising slope of a mountain range ) tend to become larger , resulting in turbulent airflow and convective activity . Instability can lead to significant turbulence , extensive vertical clouds , and severe weather such as thunderstorms . Adiabatic cooling and heating are phenomena of rising or descending air . Rising air expands and cools due to the decrease in air pressure as altitude increases . The opposite is true of descending air ; as atmospheric pressure increases , the temperature of descending air increases as it is compressed . Adiabatic heating and adiabatic cooling are terms used to describe this temperature change . The adiabatic lapse rate is the rate at which a rising or falling air mass lowers or increases per distance of vertical displacement . The ambient lapse rate is the temperature change in the ( non-displaced ) air per vertical distance . Instability results from difference between the adiabatic lapse rate of an air mass and the ambient lapse rate in the atmosphere . If the adiabatic lapse rate is lower than the ambient lapse rate , an air mass displaced upward cools less rapidly than the air in which it is moving . Hence , such an air mass becomes warmer relative to the atmosphere . As warmer air is less dense , such an air mass would tend to continue to rise . Conversely , if the adiabatic lapse rate is higher than the ambient lapse rate , an air mass displaced upward cools more rapidly than the air in which it is moving . Hence , such an airmass becomes cooler relative to the atmosphere . As cooler air is more dense , the rise of such an airmass would tend to be resisted . When air rises , moist air cools at a lower rate than dry air . That is , for the same vertical movement , a parcel of moist air will be warmer than a parcel of dry air . This is because of the condensation of water vapor in the air parcel due to expansion cooling . As water vapor condenses , latent heat is released into the air parcel . Moist air has more water vapor than dry air , so more latent heat is released into the parcel of moist air as it rises . Dry air does not have as much water vapor , therefore dry air cools at a higher rate with vertical movement than moist air . As a result of the latent heat that is released during water vapor condensation , moist air has a relatively lower adiabatic lapse rate than dry air . This makes moist air generally less stable than dry air ( see convective available potential energy -LSB- CAPE -RSB- ) . The dry adiabatic lapse rate ( for unsaturated air ) is 3 C-change per 1,000 vertical feet ( 300 m ) . The moist adiabatic lapse rate varies from 1.1 to per 1,000 vertical feet ( 300 m ) . The combination of moisture and temperature determine the stability of the air and the resulting weather . Cool , dry air is very stable and resists vertical movement , which leads to good and generally clear weather . The greatest instability occurs when the air is moist and warm , as it is in the tropical regions in the summer . Typically , thunderstorms appear on a daily basis in these regions due to the instability of the surrounding air . The ambient lapse rate differs in different meteorological conditions , but , on average , is 2 C-change per 1,000 vertical feet ( 300 m ) . |
Cryoseism | A cryoseism , also known as an ice quake or a frost quake , is a seismic event that may be caused by a sudden cracking action in frozen soil or rock saturated with water or ice . As water drains into the ground , it may eventually freeze and expand under colder temperatures , putting stress on its surroundings . This stress builds up until relieved explosively in the form of a cryoseism . Another type of cryoseism is a non-tectonic seismic event caused by sudden glacial movements . This movement has been attributed to a veneer of water which may pool underneath a glacier sourced from surface ice melt . Hydraulic pressure of the liquid can act as a lubricant , allowing the glacier to suddenly shift position . This type of cryoseism can be very brief , or may last for several minutes . The requirements for a cryoseism to occur are numerous ; therefore , accurate predictions are not entirely possible and may constitute a factor in structural design and engineering when constructing in an area historically known for such events . Speculation has been made between global warming and the frequency of cryoseisms . |
Cryogenian | The Cryogenian ( -LSB- pronkraɪoʊˈdʒɛniən -RSB- , from Greek cryos `` cold '' and genesis `` birth '' ) is a geologic period that lasted from . It forms the second geologic period of the Neoproterozoic Era , preceded by the Tonian Period and followed by the Ediacaran . The Sturtian and Marinoan glaciations during the Cryogenian period , which are the greatest ice ages known to have occurred on Earth , occurred during this period . These events are the subject of much scientific controversy . The main debate contests whether these glaciations covered the entire planet ( the so-called ` Snowball Earth ' ) or if a band of open sea survived near the equator ( termed ` slushball Earth ' ) . |
Contiguous_United_States | The contiguous United States consists of the 48 adjoining U.S. states plus Washington , D.C. ( federal district ) , on the continent of North America . The term excludes the non-contiguous states of Alaska and Hawaii and all off-shore United States territories and possessions , which include American Samoa , Guam , the Northern Mariana Islands , Puerto Rico , and the U.S. Virgin Islands . The greatest distance ( on a great circle route ) entirely within the 48 contiguous states is 2,802 miles ( 4,509 km , between Florida and the state of Washington ) ; the greatest north-south line is 1,650 miles ( 2,660 km ) . Together , the 48 contiguous states and Washington , D.C. occupy a combined area of 3,119,884.69 sqmi , which is 1.58 % of the total surface area of Earth . Of this area , 2,959,064.44 sqmi is land , composing 83.65 % of U.S. land area , similar to the area of Australia . Officially , 160,820.25 sqmi is water area , composing 62.66 % of the nation 's total water area . The contiguous United States would be placed 5th in the list of sovereign states and dependencies by area ; the total area of the country , including Alaska and Hawaii , ranks fourth . Brazil is the only country that is larger in total area than the contiguous United States , but smaller than the entire United States , while Russia , Canada and China are the only three countries larger than both . The 2010 census population of this area was 306,675,006 , comprising 99.33 % of the nation 's population , and a density of 103.639 inhabitants/sq mi ( 40.015 / km2 ) , compared to 87.264 / sq mi ( 33.692 / km2 ) for the nation as a whole . |
Damper_(flow) | A damper is a valve or plate that stops or regulates the flow of air inside a duct , chimney , VAV box , air handler , or other air handling equipment . A damper may be used to cut off central air conditioning ( heating or cooling ) to an unused room , or to regulate it for room-by-room temperature and climate control . Its operation can be manual or automatic . Manual dampers are turned by a handle on the outside of a duct . Automatic dampers are used to regulate airflow constantly and are operated by electric or pneumatic motors , in turn controlled by a thermostat or building automation system . Automatic or motorized dampers may also be controlled by a solenoid , and the degree of air-flow calibrated , perhaps according to signals from the thermostat going to the actuator of the damper in order to modulate the flow of air-conditioned air in order to effect climate control . In a chimney flue , a damper closes off the flue to keep the weather ( and birds and other animals ) out and warm or cool air in . This is usually done in the summer , but also sometimes in the winter between uses . In some cases , the damper may also be partly closed to help control the rate of combustion . The damper may be accessible only by reaching up into the fireplace by hand or with a woodpoker , or sometimes by a lever or knob that sticks down or out . On a wood-burning stove or similar device , it is usually a handle on the vent duct as in an air conditioning system . Forgetting to open a damper before beginning a fire can cause serious smoke damage to the interior of a home , if not a house fire . |
Costa_Ricans | Costa Ricans ( Spanish : Costarricenses ) , also called Ticos , are from a multiethnic Spanish speaking nation in Central America called Costa Rica . Costa Ricans are predominantly mestizos , whites and castizos ( halfway between white and mestizo ) , but their country is considered a multiethnic society , which means that it is home to people of many different ethnic backgrounds . As a result , modern-day Costa Ricans do not consider their nationality as an ethnicity but as a citizenship with various ethnicities . Costa Rica has four small minority groups : Mulattoes , Blacks , Asians , and Amerindians . In addition to the `` Indigenas '' , whites , mestizos , blacks and mulattoes , Costa Rica is also home to thousands of Asians . Most of the Chinese and Indians now living in the country are descendants of those that arrived during the 19th century as migrant workers . According to the 2011 Census , Costa Rica has a population of 4,301,712 people . The population growth rate between 2005 and 2010 was estimated to be 1.5 % annually , with a birth rate of 17.8 live births per 1,000 inhabitants and a mortality rate of 4.1 deaths per 1,000 inhabitants . Costa Rica was the point where the Mesoamerican and South American native cultures met . The northwest of the country , the Nicoya peninsula , was the southernmost point of Nahuatl cultural influence when the Spanish conquerors ( conquistadores ) came in the 16th century . The central and southern portions of the country had Chibcha influences . The Atlantic coast , meanwhile , was populated with Jamaican immigrant workers during the 19th century . The country has received immigration from Europe , Africa , Asia , Americas , Middle East etc. . |
Cosmic-ray_observatory | A cosmic-ray observatory is a scientific installation built to detect high-energy-particles coming from space called cosmic rays . This typically includes photons ( high-energy light ) , electrons , protons , and some heavier nuclei , as well as antimatter particles . About 90 % of cosmic rays are protons , 9 % are alpha particles , and the rest are other particles It is not yet possible to build image forming optics for cosmic rays , like a Wolter telescope for lower energy X-rays , although some cosmic-ray observatories also look for high energy gamma rays and x-rays . Ultra-high-energy cosmic rays ( UHEC ) pose further detection problems . One way of learning about cosmic rays is using different detectors to observe aspects of a cosmic ray air shower . Methods of detection for Gamma-rays . Scintillation Detectors Solid State Detectors Compton Scattering Pair Telescopes Air Cerenkov Detectors For example , while a visible light photon may have an energy of a few eV , a cosmic gamma ray may exceed a TeV ( 1,000,000,000,000 eV ) . Sometimes cosmic gamma rays ( photons ) are not grouped with nuclei cosmic rays . |
Dakota_Access_Pipeline | The Dakota Access Pipeline ( DAPL ) or Bakken pipeline is a 1172 mi underground oil pipeline project in the United States . The route begins in the Bakken shale oil fields in northwest North Dakota and continues in a straight line south-east , through South Dakota and Iowa , terminating at the oil tank farm near Patoka , Illinois . Together with the Energy Transfer Crude Oil Pipeline from Patoka to Nederland , Texas , it forms the Bakken system . The $ 3.78 billion project was announced to the public in June 2014 , and informational hearings for landowners took place between August 2014 and January 2015 . Dakota Access , LLC , a Houston , Texas based company and subsidiary of Energy Transfer Partners , L.P.started constructing the pipeline in June 2016 . Its minor partners are Phillips 66 , Enbridge , and Marathon Petroleum . On November 26 , 2016 , the project was reported to be 87 % completed . It was planned for completion by January 1 , 2017 . However , the project was delayed by the Army Corps of Engineers ' December 2016 to deny an easement across Lake Oahe , part of the Missouri River . The pipeline has been controversial regarding its necessity and impact on the environment . A number of Native Americans in Iowa and the Dakotas have opposed the pipeline , including the Meskwaki and several Sioux tribal nations , under the assertion that the pipeline would threaten sacred burial grounds as well as the quality of water in the area . In August 2016 , ReZpect Our Water , a group organized on the Standing Rock Indian Reservation , brought a petition to the U.S. Army Corps of Engineers ( USACE ) in Washington , D.C. , and the tribe sued for an injunction . A protest at the pipeline site in North Dakota , near the Standing Rock Indian Reservation , has drawn international attention . In January 2017 , President Donald Trump issued a memorandum directing the USACE to expedite the project . After the USACE approved the final easement under Lake Oahe on February 9 , allowing Dakota Access to complete the pipeline , the decision was challenged in a lawsuit by the Cheyenne River Sioux . The pipeline was completed by April , and first delivery of oil through the pipeline is projected for May 14 , 2017 . |
Cryovolcano | A cryovolcano ( colloquially known as an ice volcano ) is a theoretical type of volcano that erupts volatiles such as water , ammonia or methane , instead of molten rock . Collectively referred to as cryomagma or ice-volcanic melt , these substances are usually liquids and can form plumes , but can also be in vapour form . After eruption , cryomagma is expected to condense to a solid form when exposed to the very low surrounding temperature . Cryovolcanoes may potentially form on icy moons and other objects with abundant water past the Solar System 's snow line ( such as Pluto ) . A number of features have been identified as possible cryovolcanoes on Pluto , Titan and Ceres . In addition , although they are not known to form volcanoes , ice geysers have been observed on Enceladus and potentially Triton . One potential energy source on some solar system bodies for melting ices and producing cryovolcanoes is tidal friction . It has also been suggested that translucent deposits of frozen materials could create a subsurface greenhouse effect that would accumulate the required heat . Signs of past warming of the Kuiper belt object Quaoar have led scientists to speculate that it exhibited cryovolcanism in the past . Radioactive decay could provide the energy necessary for such activity , as cryovolcanoes can emit water mixed with ammonia , which would melt at − 95 ° C and create an extremely cold liquid that would flow out of the volcano . |
Convective_heat_transfer | Convective heat transfer , often referred to simply as convection , is the transfer of heat from one place to another by the movement of fluids . Convection is usually the dominant form of heat transfer in liquids and gases . Although often discussed as a distinct method of heat transfer , convective heat transfer involves the combined processes of unknown conduction ( heat diffusion ) and advection ( heat transfer by bulk fluid flow ) . Convection can be `` forced '' by movement of a fluid by means other than buoyancy forces ( for example , a water pump in an automobile engine ) . Thermal expansion of fluids may also force convection . In other cases , natural buoyancy forces alone are entirely responsible for fluid motion when the fluid is heated , and this process is called `` natural convection '' . An example is the draft in a chimney or around any fire . In natural convection , an increase in temperature produces a reduction in density , which in turn causes fluid motion due to pressures and forces when fluids of different densities are affected by gravity ( or any g-force ) . For example , when water is heated on a stove , hot water from the bottom of the pan rises , displacing the colder denser liquid , which falls . After heating has stopped , mixing and conduction from this natural convection eventually result in a nearly homogeneous density , and even temperature . Without the presence of gravity ( or conditions that cause a g-force of any type ) , natural convection does not occur , and only forced-convection modes operate . The convection heat transfer mode comprises one mechanism . In addition to energy transfer due to specific molecular motion ( diffusion ) , energy is transferred by bulk , or macroscopic , motion of the fluid . This motion is associated with the fact that , at any instant , large numbers of molecules are moving collectively or as aggregates . Such motion , in the presence of a temperature gradient , contributes to heat transfer . Because the molecules in aggregate retain their random motion , the total heat transfer is then due to the superposition of energy transport by random motion of the molecules and by the bulk motion of the fluid . It is customary to use the term convection when referring to this cumulative transport and the term advection when referring to the transport due to bulk fluid motion . |
Creation–evolution_controversy | The creation -- evolution controversy ( also termed the creation vs. evolution debate or the origins debate ) involves an ongoing , recurring cultural , political , and theological dispute about the origins of the Earth , of humanity , and of other life . Within the Christian world creationism was once widely believed to be true , but since the mid-19th century evolution by natural selection has been established as an empirical scientific fact . Efforts to sustain the traditional view are widely regarded in the scientific community as pseudoscience . While the controversy has a long history , today it has retreated to be mainly over what constitutes good science education , with the politics of creationism primarily focusing on the teaching of creation and evolution in public education . Among majority-Christian countries , the debate is most prominent in the United States , and to a lesser extent in Europe and elsewhere , and is often portrayed as part of a culture war . Parallel controversies also exist in some other religious communities , such as the more fundamentalist branches of Judaism and Islam . Christian fundamentalists dispute the evidence of common descent of humans and other animals as demonstrated in modern paleontology , genetics , histology and cladistics and those other sub-disciplines which are based upon the conclusions of modern evolutionary biology , geology , cosmology , and other related fields . They argue for the Abrahamic accounts of creation , framing them as reputable science ( `` creation science '' ) . The Catholic Church now recognizes the existence of evolution ( see Catholic Church and evolution ) . Pope Francis has stated : `` God is not a divine being or a magician , but the Creator who brought everything to life ... Evolution in nature is not inconsistent with the notion of creation , because evolution requires the creation of beings that evolve . '' The rules of genetic evolutionary inheritance were first discovered by a Catholic priest , the Augustinian monk Gregor Mendel , who is known today as the founder of modern genetics . According to a 2014 Gallup survey , `` More than four in 10 Americans continue to believe that God created humans in their present form 10,000 years ago , a view that has changed little over the past three decades . Half of Americans believe humans evolved , with the majority of these saying God guided the evolutionary process . However , the percentage who say God was not involved is rising . '' The debate is sometimes portrayed as being between science and religion , and the United States National Academy of Sciences states : |
Convection | Convection is the movement of groups of molecules within fluids such as gases and liquids , including molten rock ( rheid ) . Convection takes place through advection , diffusion or both . Convection can not take place in most solids because neither bulk current flows nor significant diffusion of matter can take place . Diffusion of heat can take place in rigid solids , but that is called heat conduction . However , can take place in soft solids or mixtures where solid particles can move past each other . Thermal convection can be demonstrated by placing a heat source ( e.g. a Bunsen burner ) at the side of a glass full of a liquid , and observing the changes in temperature in the glass caused by the warmer ghost fluid circulating into cooler areas . Convective heat transfer is one of the major types of heat transfer , and convection is also a major mode of mass transfer in fluids . Convective heat and mass transfer take place both by diffusion -- the random Brownian motion of individual particles in the fluid -- and by advection , in which matter or heat is transported by the larger-scale motion of currents in the fluid . In the context of heat and mass transfer , the term `` convection '' is used to refer to the sum of advective and diffusive transfer . In common use the term `` convection '' may refer loosely to heat transfer by convection , as opposed to mass transfer by convection , or the convection process in general . Sometimes `` convection '' is even used to refer specifically to `` free heat convection '' ( natural heat convection ) as opposed to forced heat convection . However , in mechanics the correct use of the word is the general sense , and different types of convection should be qualified for clarity . Convection can be qualified in terms of being natural , forced , gravitational , granular , or thermomagnetic . It may also be said to be due to combustion , capillary action , or Marangoni and Weissenberg effects . Heat transfer by natural convection plays a role in the structure of Earth 's atmosphere , its oceans , and its mantle . Discrete convective cells in the atmosphere can be seen as clouds , with stronger convection resulting in thunderstorms . Natural convection also plays a role in stellar physics . |
Cordilleran_Ice_Sheet | The Cordilleran ice sheet was a major ice sheet that periodically covered large parts of North America during glacial periods over the last ~ 2.6 million years . This included the following areas : Western Montana The Idaho Panhandle Northern Washington state down to about Olympia and Spokane All of British Columbia The southwestern third or so of Yukon Territory All of the Alaska Panhandle South Central Alaska The Alaska Peninsula Almost all of the continental shelf north of the Strait of Juan de Fuca The ice sheet covered up to 2.5 million square kilometres at the Last Glacial Maximum and probably more than that in some previous periods , when it may have extended into the northeast extremity of Oregon and the Salmon River Mountains in Idaho . It is probable , though , that its northern margin also migrated south due to the influence of starvation caused by very low levels of precipitation . At its eastern end the Cordilleran ice sheet merged with the Laurentide ice sheet at the Continental Divide , forming an area of ice that contained one and a half times as much water as the Antarctic ice sheet does today . At its western end it is believed nowadays that several small glacial refugia existed during the last glacial maximum below present sea level in the now-submerged Hecate Strait and on the Brooks Peninsula in northern Vancouver Island . However , evidence of ice-free refugia above present sea level north of the Olympic Peninsula has been refuted by genetic and geological studies since the middle 1990s . The ice sheet faded north of the Alaska Range because the climate was too dry to form glaciers . Unlike the Laurentide ice sheet , which is believed to have taken as much as eleven thousand years to fully melt , it is believed the Cordilleran ice sheet , except for areas that remain glaciated today , melted very quickly , probably in four thousand years or less . This rapid melting caused such floods as the overflow of Lake Missoula and shaped the topography of the extremely fertile Inland Empire of Eastern Washington . |
Crane_(bird) | Cranes are a family , Gruidae , of large , long-legged and long-necked birds in the group Gruiformes . There are fifteen species of crane in four genera . Unlike the similar-looking but unrelated herons , cranes fly with necks outstretched , not pulled back . Cranes live on all continents except Antarctica and South America . They are opportunistic feeders that change their diet according to the season and their own nutrient requirements . They eat a range of items from suitably sized small rodents , fish , amphibians , and insects to grain , berries , and plants . Cranes construct platform nests in shallow water , and typically lay two eggs at a time . Both parents help to rear the young , which remain with them until the next breeding season . Some species and populations of cranes migrate over long distances ; others do not migrate at all . Cranes are solitary during the breeding season , occurring in pairs , but during the non-breeding season they are gregarious , forming large flocks where their numbers are sufficient . Most species of cranes have been affected by human activities and are at the least classified as threatened , if not critically endangered . The plight of the whooping cranes of North America inspired some of the first US legislation to protect endangered species . |
Cougar | The cougar ( Puma concolor ) , also commonly known as the mountain lion , puma , panther , or catamount , is a large felid of the subfamily Felinae native to the Americas . Its range , from the Canadian Yukon to the southern Andes of South America , is the greatest of any large wild terrestrial mammal in the Western Hemisphere . An adaptable , generalist species , the cougar is found in most American habitat types . It is the second-heaviest cat in the New World , after the jaguar . Secretive and largely solitary by nature , the cougar is properly considered both nocturnal and crepuscular , although there are daytime sightings . The cougar is more closely related to smaller felines , including the domestic cat ( subfamily Felinae ) , than to any species of subfamily Pantherinae , of which only the jaguar is native to the Americas . The cougar is an ambush predator and pursues a wide variety of prey . Primary food sources are ungulates , particularly deer , but also livestock . It also hunts species as small as insects and rodents . This cat prefers habitats with dense underbrush and rocky areas for stalking , but can also live in open areas . The cougar is territorial and survives at low population densities . Individual territory sizes depend on terrain , vegetation , and abundance of prey . While large , it is not always the apex predator in its range , yielding to the jaguar , gray wolf , American black bear , and grizzly bear . It is reclusive and mostly avoids people . Fatal attacks on humans are rare , but have recently been increasing in North America as more people enter their territories . Intensive hunting following European colonization of the Americas and the ongoing human development of cougar habitat has caused populations to drop in most parts of its historical range . In particular , the cougar was extirpated in eastern North America in the beginning of the 20th century , except for an isolated Florida panther subpopulation . Transient males have been verified in Minnesota , Missouri , Wisconsin , Iowa , the Upper Peninsula of Michigan , and Illinois , where a cougar was shot in the city limits of Chicago and , in at least one instance , observed as far east as coastal Connecticut . Reports of eastern cougars ( P. c. cougar ) still surface , although it was declared extirpated in 2011 . |
Counterfactual_thinking | Counterfactual thinking is a concept in psychology that involves the human tendency to create possible alternatives to life events that have already occurred ; something that is contrary to what actually happened . Counterfactual thinking is , as it states : `` counter to the facts . '' These thoughts consist of the `` What if ? '' and the `` If I had only ... '' that occur when thinking of how things could have turned out differently . Counterfactual thoughts include things that could never happen in reality because they solely pertain to events that have occurred in the past . |
Contrail | Contrails ( -LSB- ˈkɒntreɪlz -RSB- short for `` condensation trails '' ) are line-shaped clouds sometimes produced by aircraft engine exhaust , typically at aircraft cruise altitudes several miles above the Earth 's surface . Contrails are composed primarily of water , in the form of ice crystals . The combination of water vapor in aircraft engine exhaust and the low ambient temperatures that often exist at these high altitudes allows the formation of the trails . Impurities in the engine exhaust from the fuel , including sulfur compounds ( 0.05 % by weight in jet fuel ) provide some of the particles that can serve as sites for water droplet growth in the exhaust and , if water droplets form , they might freeze to form ice particles that compose a contrail . Their formation can also be triggered by changes in air pressure in wingtip vortices or in the air over the entire wing surface . Contrails , and other clouds directly resulting from human activity , are collectively named homogenitus . Depending on the temperature and humidity at the altitude the contrails form , they may be visible for only a few seconds or minutes , or may persist for hours and spread to be several miles wide , eventually resembling natural cirrus or altocumulus clouds . Persistent contrails are of particular interest to scientists because they increase the cloudiness of the atmosphere . The resulting cloud forms are formally described as homomutatus , and may resemble cirrus , cirrocumulus , or cirrostratus , and are sometimes called cirrus aviaticus . Persistent spreading contrails are suspected to have an effect on global climate . |
Cretaceous–Paleogene_extinction_event | The Cretaceous -- Paleogene ( K -- Pg ) extinction event , also known as the Cretaceous -- Tertiary ( K -- T ) extinction , was a mass extinction of some three-quarters of the plant and animal species on Earth that occurred over a geologically short period of time approximately 65 million years ago . With the exception of some ectothermic species like the leatherback sea turtle and crocodiles , no tetrapods weighing more than 25 kg survived . It marked the end of the Cretaceous period and with it , the entire Mesozoic Era , opening the Cenozoic Era that continues today . In the geologic record , the K -- Pg event is marked by a thin layer of sediment called the K -- Pg boundary , which can be found throughout the world in marine and terrestrial rocks . The boundary clay shows high levels of the metal iridium , which is rare in the Earth 's crust but abundant in asteroids . As originally proposed in 1980 by a team of scientists led by Luis Alvarez , it is now generally thought that the K -- Pg extinction was caused by a massive comet or asteroid impact , estimated to be 10 km wide , 66 million years ago and its catastrophic effects on the global environment , including a lingering impact winter that made it impossible for plants and plankton to carry out photosynthesis . The impact hypothesis , also known as the Alvarez hypothesis , was bolstered by the discovery of the 180 km Chicxulub crater in the Gulf of Mexico in the early 1990s , which provided conclusive evidence that the K -- Pg boundary clay represented debris from an asteroid impact . The fact that the extinctions occurred at the same time as the impact provides strong situational evidence that the K -- Pg extinction was caused by the asteroid . It was possibly accelerated by the creation of the Deccan Traps . However , some scientists maintain the extinction was caused or exacerbated by other factors , such as volcanic eruptions , climate change , or sea level change , separately or together . A wide range of species perished in the K -- Pg extinction . The best-known victims are the non-avian dinosaurs . However , the extinction also destroyed a plethora of other terrestrial organisms , including certain mammals , pterosaurs , birds , lizards , insects , and plants . In the oceans , the K -- Pg extinction killed off plesiosaurs and the giant marine lizards ( Mosasauridae ) and devastated fish , sharks , mollusks ( especially ammonites , which became extinct ) and many species of plankton . It is estimated that 75 % or more of all species on Earth vanished . Yet the devastation caused by the extinction also provided evolutionary opportunities . In the wake of the extinction , many groups underwent remarkable adaptive radiations -- a sudden and prolific divergence into new forms and species within the disrupted and emptied ecological niches resulting from the event . Mammals in particular diversified in the Paleogene , producing new forms such as horses , whales , bats , and primates . Birds , fish and perhaps lizards also radiated . |
Crown_corporations_of_Canada | Canadian Crown corporations are state-owned enterprises owned by the Sovereign of Canada ( ie . the Crown ) . They are established by an Act of Parliament or Act of a provincial legislature and report to that body via a minister of the Crown in the relevant cabinet , though they are `` shielded from constant government intervention and legislative oversight '' and thus `` generally enjoy greater freedom from direct political control than government departments . '' Crown corporations have a very long standing presence in the country and have been instrumental in the formation of the state . They can provide services required by the public that otherwise would not be economically viable as a private enterprise , or do n't fit exactly within the scope of any ministry . They are involved in everything from the distribution , use , and price of certain goods and services to energy development , resource extraction , public transportation , cultural promotion , and property management . |
Contraction_and_Convergence | Contraction and Convergence ( C&C ) is a proposed global framework for reducing greenhouse gas emissions to combat climate change . Conceived by the Global Commons Institute -LSB- GCI -RSB- in the early 1990s , the Contraction and Convergence strategy consists of reducing overall emissions of greenhouse gases to a safe level ( contraction ) , resulting from every country bringing its emissions per capita to a level which is equal for all countries ( convergence ) . It is intended to form the basis of an international agreement which will reduce carbon dioxide emissions to avoid dangerous climate change , carbon dioxide being the gas that is primarily responsible for changes in the greenhouse effect on Earth . It is expressed as a simple mathematical formula . This formula can be used as a way for the world to stabilize carbon levels at any level . Advocates of Contraction and Convergence stress that negotiations at the United Nations Framework Convention on Climate Change -LSB- UNFCCC -RSB- are governed sequentially by the ` objective ' of the UNFCCC -LSB- safe and stable GHG concentration in the global atmosphere -RSB- followed by its organising principles -LSB- ` precaution ' and ` equity ' -RSB- . C&C is widely cited and supported . |
Cooling_center | A cooling center is a air-conditioned public space set up by local authorities to temporarily deal with the health effects of a heat wave . Cooling centers are meant to prevent hyperthermia caused by heat , humidity , and poor air quality . Cooling centers provide shade , water , and restrooms ; medical attention and referrals to social services may also be offered . Their services are aimed at the homeless , at-risk populations such as the elderly , and those without air conditioning . As the danger of heat waves has risen in the public consciousness , cooling centers are increasingly used in cities such as New York City , Chicago , Boston , and Toronto , as well as less urban population areas . Cooling centers may also be used in places like Seattle where home air conditioning is rare but summer can bring temperatures exceeding 90 F for several days . They are usually sited at multiple locations throughout a municipality , such as public libraries , community centers , senior centers , and police stations . Another health measure sometimes taken during heat waves is to extend operational hours at public beaches and swimming pools . |
County_(United_States) | In the United States , an administrative or political sub-division of a state is a county , which is a region having specific boundaries and usually some level of governmental authority . The term `` county '' is used in 48 U.S. states , while Louisiana and Alaska have functionally equivalent subdivisions called parishes and boroughs respectively . Most counties have subdivisions which may include municipalities and unincorporated areas . Others have no further divisions , or may serve as a singular consolidated city-county . Some municipalities are in multiple counties ; New York City is uniquely partitioned into multiple counties/boroughs . The U.S. federal government uses the term `` county equivalent '' to describe non-county administrative or statistical areas that are comparable to counties . Louisiana parishes ; the organized boroughs of Alaska ; the District of Columbia ; and the independent cities of the states of Virginia , Maryland , Missouri , and Nevada are equivalent to counties for administrative purposes . Alaska 's Unorganized Borough is divided into 11 census areas that are statistically equivalent to counties . As of 2013 , the United States has 3,007 counties and 137 county equivalents for a total of 3,144 counties and county equivalents . The number of counties per state ranges from the 3 counties of Delaware to the 254 counties of Texas . Counties have significant governmental functions in all states except Rhode Island and Connecticut , where county governments have been abolished but the entities remain for administrative or statistical purposes . The Commonwealth of Massachusetts has removed most government functions from eight of its 14 counties . The county with the largest population , Los Angeles County ( 10,170,292 ) , and the county with the largest land area ( San Bernardino County ) border each other in Southern California ( however four Boroughs in Alaska are larger in area than San Bernardino ) . |
Corruption_Perceptions_Index | Transparency International ( TI ) has published the Corruption Perceptions Index ( CPI ) since 1996 , annually ranking countries `` by their perceived levels of corruption , as determined by expert assessments and opinion surveys . '' The CPI generally defines corruption as `` the misuse of public power for private benefit . '' The CPI currently ranks 168 countries `` on a scale from 100 ( very clean ) to 0 ( highly corrupt ) . '' |
Copenhagen_Diagnosis | The Copenhagen Diagnosis is a report written by twenty-six climate scientists from eight countries . It was published in 2009 and was a summary of the peer-reviewed literature to date . The Copenhagen Diagnosis is a follow-up of the previous Intergovernmental Panel on Climate Change 's Working Group 1 Report . The studies summarized , which date back to the cutoff point of the Working Group 1 Report , are those that authors viewed most relevant to the discussions at the 2009 United Nations Climate Change Conference . The Copenhagen Diagnosis served as the midpoint between IPCC -- AR4 and IPCC-AR5 . In total , the Copenhagen Diagnosis contains eight main sections , which are : Surging Greenhouse gas emissions Since 1990 , the combined global emission of carbon dioxide from various origins , such as cement production , deforestation , and fossil fuel burning , has increased 27 % . Human-induced warming Studies conducted by Lee and Rind show that only 10 % of global warming over the past century was due to the Sun . Acceleration of melting ice caps Glaciers and melting ice caps can contribute to about 8/10ths of a meter to global sea level rise . Rapid Arctic sea-ice decline According to simulations run by NCAR Climate System Model version 3 , the Arctic summer is expected to be ice-free by 2040 . Underestimation of changing sea levels In contrast to previous IPCC , the rate of sea level rise ( 3.4 mm/yr over the past 15 years ) has increased around 80 % faster than previously predicted . Damage due to inaction A region of permafrost , called the Yedoma , stores about 500 Gt of CO2 and , once released due to rising global temperatures , will increase global temperatures even more . Turning point must come soon The largest climate science conference , held in 2009 , has stated , `` Temperature rises above 2 ° C will be difficult for contemporary societies to cope with , and are likely to cause major societal and environmental disruptions through the rest of the century and beyond . '' The Future By 2100 , global mean air-temperature is projected to warm by 2 ° C -- 7 ° C above pre-industrial levels . |
DICE_model | The Dynamic Integrated Climate-Economy model , referred to as the DICE model or Dice model , is a computer-based integrated assessment model developed by William Nordhaus that `` integrates in an end-to-end fashion the economics , carbon cycle , climate science , and impacts in a highly aggregated model that allows a weighing of the costs and benefits of taking steps to slow greenhouse warming . '' Nordhaus also developed the RICE model ( Regional Integrated Climate-Economy model ) , a variant of the DICE model that was updated and developed alongside the DICE model . Others who collaborated with Nordhaus to develop the model include David Popp , Zili Yang , Joseph Boyer , and other colleagues . The DICE model is one of the three main integrated assessment models used by the United States Environmental Protection Agency , and it provides estimates intermediate between the other two models . |
Cosmology | Cosmology ( from the Greek κόσμος , kosmos `` world '' and - λογία , - logia `` study of '' ) is the study of the origin , evolution , and eventual fate of the universe . Physical cosmology is the scholarly and scientific study of the origin , large-scale structures and dynamics , and ultimate fate of the universe , as well as the scientific laws that govern these realities . The term cosmology was first used in English in 1656 in Thomas Blount 's Glossographia , and in 1731 taken up in Latin by German philosopher Christian Wolff , in Cosmologia Generalis . Religious or mythological cosmology is a body of beliefs based on mythological , religious , and esoteric literature and traditions of creation and eschatology . Physical cosmology is studied by scientists , such as astronomers and physicists , as well as philosophers , such as metaphysicians , philosophers of physics , and philosophers of space and time . Because of this shared scope with philosophy , theories in physical cosmology may include both scientific and non-scientific propositions , and may depend upon assumptions that can not be tested . Cosmology differs from astronomy in that the former is concerned with the Universe as a whole while the latter deals with individual celestial objects . Modern physical cosmology is dominated by the Big Bang theory , which attempts to bring together observational astronomy and particle physics ; more specifically , a standard parameterization of the Big Bang with dark matter and dark energy , known as the Lambda-CDM model . Theoretical astrophysicist David N. Spergel has described cosmology as a `` historical science '' because `` when we look out in space , we look back in time '' due to the finite nature of the speed of light . |
Cyclic_succession | Cyclic succession is a pattern of vegetation change in which in a small number of species tend to replace each other over time in the absence of large-scale disturbance . Observations of cyclic replacement have provided evidence against traditional Clementsian views of an end-state climax community with stable species compositions . Cyclic succession is one of several kinds of ecological succession , a concept in community ecology . When used narrowly , ` cyclic succession ' refers to processes not initiated by wholesale exogenous disturbances or long-term physical changes in the environment . However , broader cyclic processes can also be observed in cases of secondary succession in which regular disturbances such as insect outbreaks can ` reset ' an entire community to a previous stage . These examples differ from the classic cases of cyclic succession discussed below in that entire species groups are exchanged , as opposed to one species for another . On geologic time scales , climate cycles can result in cyclic vegetation changes by directly altering the physical environment . |
Credibility | Credibility comprises the objective and subjective components of the believability of a source or message . Credibility has two key components : trustworthiness and expertise , which both have objective and subjective components . Trustworthiness is based more on subjective factors , but can include objective measurements such as established reliability . Expertise can be similarly subjectively perceived , but also includes relatively objective characteristics of the source or message ( e.g. , credentials , certification or information quality ) . Secondary components of credibility include source dynamism ( charisma ) and physical attractiveness . Credibility online has become an important topic since the mid-1990s . This is because the web has increasingly become an information resource . The Credibility and Digital Media Project @ UCSB highlights recent and ongoing work in this area , including recent consideration of digital media , youth , and credibility . In addition , the Persuasive Technology Lab at Stanford University has studied web credibility and proposed the principal components of online credibility and a general theory called Prominence-Interpretation Theory . |
Cool_tropics_paradox | The cool tropics paradox refers to an apparent difference between modeled estimates of tropical temperatures during warm , ice-free periods of the Cretaceous and Eocene , and the colder temperatures which proxies suggested were present . The long-standing paradox was resolved when novel proxy derived temperatures showed significantly warmer tropics during past greenhouse climates . The low-gradient problem , i.e. the very warm polar regions with respect to present day , is still an issue for state-of-the-art climate models . |
Crater_Lake_National_Park | Crater Lake National Park is a United States National Park located in southern Oregon . Established in 1902 , Crater Lake National Park is the fifth-oldest national park in the U.S. and the only national park in Oregon . The park encompasses the caldera of Crater Lake , a remnant of a destroyed volcano , Mount Mazama , and the surrounding hills and forests . The lake is 1949 ft deep at its deepest point , which makes it the deepest lake in the United States , the second-deepest in North America and the ninth-deepest in the world . Crater Lake is often referred to as the seventh-deepest lake in the world , but this former listing excludes the approximately 3000 ft depth of subglacial Lake Vostok in Antarctica , which resides under nearly 13000 ft of ice , and the recent report of a 2740 ft maximum depth for Lake O'Higgins / San Martin , located on the border of Chile and Argentina . However , when comparing its average depth of 1148 ft to the average depth of other deep lakes , Crater Lake becomes the deepest in the Western Hemisphere and the third-deepest in the world . The impressive average depth of this volcanic lake is due to the nearly symmetrical 4000 ft caldera formed 7,700 years ago during the violent climactic eruptions and subsequent collapse of Mount Mazama and the relatively moist climate that is typical of the crest of the Cascade Range . The caldera rim ranges in elevation from 7000 to . The United States Geological Survey benchmarked elevation of the lake surface itself is 6178 ft. This National Park encompasses 183224 acre . Crater Lake has no streams flowing into or out of it . All water that enters the lake is eventually lost from evaporation or subsurface seepage . The lake 's water commonly has a striking blue hue , and the lake is re-filled entirely from direct precipitation in the form of snow and rain . |
Copernicus_Climate_Change_Service_(C3S) | The Copernicus Climate Change Service ( C3S ) is one of the six thematic services provided by the European Union 's Copernicus Programme . The Copernicus Programme is managed by the European Commission and the C3S is implemented by the European Centre for Medium-Range Weather Forecasts ( ECMWF ) and is expected to become operational in 2018 . The objective of the Copernicus Climate Change Service is to build an EU knowledge base in support of mitigation and adaptation policies for Climate Change and Global Warming . The goal of the operational Climate Change service is to provide reliable information about the current and past state of the climate , the forecasts on a seasonal time scale , and the more likely projections in the coming decades for various scenarios of greenhouse gas emissions and other Climate Change contributors . |
Cynicism_(contemporary) | Cynicism is an attitude or state of mind characterized by a general distrust of others ' motives . A cynic may have a general lack of faith or hope in the human species or people motivated by ambition , desire , greed , gratification , materialism , goals , and opinions that a cynic perceives as vain , unobtainable , or ultimately meaningless and therefore deserving of ridicule or admonishment . A common misapplication of this attitude involves its attribution to individuals who emote well-thought-out expressions of skepticism . Such miscategorization may occur as the result of either inexperience and/or a belief system in which the innate goodness of man is considered an important tenet or even an irrefutable fact . Thus , contemporary usage incorporates both a form of jaded prudence and ( when misapplied ) realistic criticism or skepticism . The term originally derives from the ancient Greek philosophers , the Cynics , who rejected all conventions , whether of religion , manners , housing , dress , or decency , instead advocating the pursuit of virtue in accordance with a simple and idealistic way of life . By the 19th century , emphasis on the ascetic ideals and the critique of current civilization based on how it might fall short of an ideal civilization or negativistic aspects of Cynic philosophy led the modern understanding of cynicism to mean a disposition of disbelief in the sincerity or goodness of human motives and actions . Modern cynicism is a distrust toward professed ethical and social values , especially when there are high expectations concerning society , institutions , and authorities that are unfulfilled . It can manifest itself as a result of frustration , disillusionment , and distrust perceived as owing to organizations , authorities , and other aspects of society . |
Corona | A corona ( Latin , ` crown ' ) is an aura of plasma that surrounds the sun and other stars . The Sun 's corona extends millions of kilometres into space and is most easily seen during a total solar eclipse , but it is also observable with a coronagraph . The word `` corona '' is a Latin word meaning `` crown '' , from the Ancient Greek κορώνη ( korōnè , `` garland , wreath '' ) . The high temperature of the Sun 's corona gives it unusual spectral features , which led some in the 19th century to suggest that it contained a previously unknown element , `` coronium '' . Instead , these spectral features have since been explained by highly ionized iron ( Fe-XIV ) . Bengt Edlén , following the work of Grotrian ( 1939 ) , first identified the coronal spectral lines in 1940 ( observed since 1869 ) as transitions from low-lying metastable levels of the ground configuration of highly ionised metals ( the green Fe-XIV line at 5303 Å , but also the red line Fe-X at 6374 Å ) . These high stages of ionisation indicate a plasma temperature in excess of 1,000,000 kelvins , much hotter than the surface of the sun . Light from the corona comes from three primary sources , from the same volume of space . The K-corona ( K for kontinuierlich , `` continuous '' in German ) is created by sunlight scattering off free electrons ; Doppler broadening of the reflected photospheric absorption lines spreads them so greatly as to completely obscure them , giving the spectral appearance of a continuum with no absorption lines . The F-corona ( F for Fraunhofer ) is created by sunlight bouncing off dust particles , and is observable because its light contains the Fraunhofer absorption lines that are seen in raw sunlight ; the F-corona extends to very high elongation angles from the Sun , where it is called the zodiacal light . The E-corona ( E for emission ) is due to spectral emission lines produced by ions that are present in the coronal plasma ; it may be observed in broad or forbidden or hot spectral emission lines and is the main source of information about the corona 's composition . |
Dairy_farming_in_Canada | Dairy farming is one of the largest agricultural sectors in Canada . Dairy has a significant presence in all of the provinces and is one of the top two agricultural commodities in seven out of ten provinces . In 2016 , there were 959,600 dairy cows on 11,683 farms across the country . Quebec and Ontario are the major dairy producing provinces with 49 % and 33 % of the farms , respectively . The Canadian dairy sector contributes roughly $ 18.9 B yearly to Canada 's GDP , and sustains approximately 215,000 full-time equivalent jobs . In Canada , dairy farming is subject to the system of supply management . Under supply management , which also includes the egg and poultry sectors , farmers manage their production so that it coincides with forecasts of demand for their products over a predetermined period - while taking into account certain imports that enter Canada , as well as some production which is shipped to export markets . Imports of dairy , eggs , and poultry are controlled using tariff rate quotas , or TRQs . These allow a predetermined quantity to be imported at preferential tariff rates ( generally duty free ) , while maintaining control over how much is imported . The over-quota tariffs are set at levels that allow Canadian farmers to receive a price reflecting the cost to produce in a northern environment . |
Coral_bleaching | Coral bleaching occurs when coral polyps expel algae that lives inside their tissues . Normally , coral polyps live in an endosymbiotic relationship with the algae and that relationship is crucial for the coral and hence for the health of the whole reef . Bleached corals continue to live . But as the algae provide the coral with 90 % of its energy , after expelling the algae the coral begins to starve . Above-average sea water temperatures caused by global warming have been identified as a leading cause for coral bleaching worldwide . Between 2014 and 2016 , the longest global bleaching events ever were recorded . According to the United Nations Environment Programme , these bleaching events killed coral on an unprecedented scale . In 2016 , bleaching hit 90 percent of coral on the Great Barrier Reef and killed 29 percent of the reef 's coral . In 2017 , the bleaching further expanded to areas of the park that were previously spared , such as the central one . __ TOC __ |
Controversy | Controversy is a state of prolonged public dispute or debate , usually concerning a matter of conflicting opinion or point of view . The word was coined from the Latin controversia , as a composite of controversus -- `` turned in an opposite direction , '' from contra -- `` against '' -- and vertere -- to turn , or versus ( see verse #Latin ) , hence , `` to turn against . '' The most applicable or well known controversial subjects , topics or areas are politics , religion , philosophy , parenting and sex . History is similarly controversial . Other prominent areas of controversy are economics , science , finances , culture , education , the military , society , celebrities , organisation , the media , age , gender , and race . Controversy in matters of theology has traditionally been particularly heated , giving rise to the phrase odium theologicum . Controversial issues are held as potentially divisive in a given society , because they can lead to tension and ill will , and as a result they are often considered taboo to be discussed in the light of company in many cultures . |
Coyote | The coyote ( k ) is a canid native to North America . It is smaller than its close relative , the gray wolf , and slightly smaller than its other close relatives , the eastern wolf and the red wolf . It fills much of the same ecological niche as the golden jackal does in Eurasia , though it is larger and more predatory . It is listed as least concern by the International Union for Conservation of Nature due to its wide distribution and abundance throughout North America , southwards through Mexico , and into Central America . The species is versatile and able to adapt to environments modified by humans . As human activity has altered the landscape , the coyote 's range has expanded . In 2013 , coyotes were sighted in eastern Panama ( across the Panama Canal from their home range ) for the first time . The coyote is more closely related to the common ancestor of wolves and other canids ( more `` basal '' ) than the gray wolf . , 19 coyote subspecies are recognized . The average male coyote weighs 8 to and the average female 7 to . Their fur color is predominantly light gray and red or fulvous interspersed with black and white , though it varies somewhat with geography . It is highly flexible in social organization , living either in a family unit or in loosely knit packs of unrelated individuals . It has a varied diet consisting primarily of animal meat , including deer , rabbits , hares , rodents , birds , reptiles , amphibians , fish , and invertebrates , though it may also eat fruits and vegetables on occasion . The coyote 's characteristic vocalization is a howl made by solitary individuals . Humans aside , cougars and gray wolves are the coyote 's only serious enemies . Nevertheless , coyotes do sometimes mate with gray , eastern , or red wolves , producing hybrids colloquially called `` coywolves '' . In northeastern United States and eastern Canada , a larger species of coyote ( although still smaller than the three types of wolves ) , called the eastern coyote is the result on various historical and recent mating of the various types of wolves and coyotes . Most recent studies show that most wolves contain some level of coyote DNA . The coyote is a prominent character in Native American folklore , mainly in the Southwestern United States and Mexico , usually depicted as a trickster that alternately assumes the form of an actual coyote or a man . As with other trickster figures , the coyote uses deception and humor to rebel against social conventions . The animal was especially respected in Mesoamerican cosmology as a symbol of military might . After the European colonization of the Americas , it was reviled in Anglo-American culture as a cowardly and untrustworthy animal . Unlike wolves ( gray , eastern , or red ) , which have undergone an improvement of their public image , attitudes towards the coyote remain largely negative . |
Coriolis_force | In physics , the Coriolis force is an inertial force that acts on objects that are in motion relative to a rotating reference frame . In a reference frame with clockwise rotation , the force acts to the left of the motion of the object . In one with anticlockwise rotation , the force acts to the right . Deflection of an object due to the Coriolis force is called the Coriolis effect . Though recognized previously by others , the mathematical expression for the Coriolis force appeared in an 1835 paper by French scientist Gaspard-Gustave de Coriolis , in connection with the theory of water wheels . Early in the 20th century , the term Coriolis force began to be used in connection with meteorology . Newton 's laws of motion describe the motion of an object in an inertial ( non-accelerating ) frame of reference . When Newton 's laws are transformed to a rotating frame of reference , the Coriolis force and centrifugal force appear . Both forces are proportional to the mass of the object . The Coriolis force is proportional to the rotation rate and the centrifugal force is proportional to its square . The Coriolis force acts in a direction perpendicular to the rotation axis and to the velocity of the body in the rotating frame and is proportional to the object 's speed in the rotating frame ( more precisely , to the component of its velocity that is perpendicular to the axis of rotation ) . The centrifugal force acts outwards in the radial direction and is proportional to the distance of the body from the axis of the rotating frame . These additional forces are termed inertial forces , fictitious forces or pseudo forces . They allow the application of Newton 's laws to a rotating system . They are correction factors that do not exist in a non-accelerating or inertial reference frame . In popular ( non-technical ) usage of the term `` Coriolis effect '' , the rotating reference frame implied is almost always the Earth . Because the Earth spins , Earth-bound observers need to account for the Coriolis force to correctly analyze the motion of objects . The Earth completes only one rotation per day , so for motions of everyday objects the Coriolis force is usually quite small compared to other forces ; its effects generally become noticeable only for motions occurring over large distances and long periods of time , such as large-scale movement of air in the atmosphere or water in the ocean . Such motions are constrained by the surface of the Earth , so only the horizontal component of the Coriolis force is generally important . This force causes moving objects on the surface of the Earth to be deflected to the right ( with respect to the direction of travel ) in the Northern Hemisphere and to the left in the Southern Hemisphere . The horizontal deflection effect is greater near the poles , since the effective rotation rate about a local vertical axis is largest there , and decreases to zero at the equator . Rather than flowing directly from areas of high pressure to low pressure , as they would in a non-rotating system , winds and currents tend to flow to the right of this direction north of the equator and to the left of this direction south of it . This effect is responsible for the rotation of large cyclones ( see Coriolis effects in meteorology ) . For an intuitive explanation of the origin of the Coriolis force , consider an object moving northward in the northern hemisphere . Viewed from outer space , the object does not appear to go due north , but has an eastward motion ( it rotates around toward the right along with the surface of the Earth ) . The further north you go , the smaller the `` horizontal diameter '' of the Earth , and so the slower the eastward motion of its surface . As the object moves north , to higher latitudes , it has a tendency to maintain the eastward speed it started with ( rather than slowing down to match the reduced eastward speed of local objects on the Earth 's surface ) , so it veers east ( i.e. to the right of its initial motion ) . Though not obvious from this example , which considers northward motion , the horizontal deflection occurs equally for objects moving east or west ( or any other direction ) . |
Copenhagen_Consensus_Center | The Copenhagen Consensus Center is a US non-profit think tank , founded and headed by Bjørn Lomborg ( best known for his controversial 2001 book , The Skeptical Environmentalist ) . The Center organizes the Copenhagen Consensus , a conference of prominent economists held every four years , where potential solutions to global issues are examined and prioritized using cost-benefit analysis . The most recent Copenhagen Consensus titled the Post-2015 Consensus was held in 2015 . It focused on the costs and benefits of the 169 global development targets of the United Nation 's Global Goals . The Post-2015 Consensus brought together an expert panel of economists including two Nobel Laureates who reviewed the research produced by the project and identified 19 targets that represent the best value-for-money in development over the period 2016 to 2030 , offering more than $ 15 back on every dollar invested . Recently , the Copenhagen Consensus Center has refocused its efforts into nationally oriented research , and is currently working extensively in Haiti and Bangladesh , while also planning expansion to India , where it is partnering with high profile and influential organisations . |
Contribution_to_global_warming_by_Australia | Australia has one of the highest per capita emissions of carbon dioxide in the world , with 0.3 % of the world 's population it produces 1.8 % of the world 's greenhouse gasses . It was 18.3 tonnes per year per person and the 11th highest in the world per capita in 2009 . Australia uses principally coal power ( 70 % ) for electricity , with the remainder mainly gas , with no nuclear , low levels of hydro power , and low , but increasing , levels of solar , wind and wave power . |
Corporate_farming | Corporate farming is a term used to describe companies that own or influence farms and agricultural practices on a large scale . This includes not only corporate ownership of farms and selling of agricultural products , but also the roles of these companies in influencing agricultural education , research , and public policy through funding initiatives and lobbying efforts . The definition and effects of corporate farming on agriculture are widely debated , though most sources that describe large businesses in agriculture as `` corporate farms '' portray their role in a negative light . |
Cumulonimbus_capillatus | A Cumulonimbus capillatus ( Latin Capillatus , `` hair '' ) is a sub-form of cumulonimbus incus . It is a cumulonimbus cloud which has reached the level of stratospheric stability and has formed the characteristic flat , anvil shaped top with dense cirrus clouds which design the cloud 's top appearance containing hair-like structures . |
Cross-sectional_data | Cross-sectional data , or a cross section of a study population , in statistics and econometrics is a type of data collected by observing many subjects ( such as individuals , firms , countries , or regions ) at the same point of time , or without regard to differences in time . Analysis of cross-sectional data usually consists of comparing the differences among the subjects . For example , if we want to measure current obesity levels in a population , we could draw a sample of 1,000 people randomly from that population ( also known as a cross section of that population ) , measure their weight and height , and calculate what percentage of that sample is categorized as obese . This cross-sectional sample provides us with a snapshot of that population , at that one point in time . Note that we do not know based on one cross-sectional sample if obesity is increasing or decreasing ; we can only describe the current proportion . Cross-sectional data differs from time series data , in which the same small-scale or aggregate entity is observed at various points in time . Another type of data , panel data ( or longitudinal data ) , combines both cross-sectional and time series data ideas and looks at how the subjects ( firms , individuals , etc. ) change over time . Panel data differs from pooled cross section data across time , because it deals with the observations on the same subjects in different times whereas the latter observes different subjects in different time periods . Panel analysis uses panel data to examine changes in variables over time and differences in variables between the subjects . In a rolling cross-section , both the presence of an individual in the sample and the time at which the individual is included in the sample are determined randomly . For example , a political poll may decide to interview 1000 individuals . It first selects these individuals randomly from the entire population . It then assigns a random date to each individual . This is the random date that the individual will be interviewed , and thus included in the survey . Cross-sectional data can be used in cross-sectional regression , which is regression analysis of cross-sectional data . For example , the consumption expenditures of various individuals in a fixed month could be regressed on their incomes , accumulated wealth levels , and their various demographic features to find out how differences in those features lead to differences in consumer behavior . |
Credible_witness | In the law of evidence , a credible witness is a person making testimony in a court or other tribunal , or acting otherwise as a witness , whose credibility is unimpeachable . A witness may have more or less credibility , or no credibility at all . In the common law system , the term ` credible witness ' may be used generally , to refer to testimony , or for the witnessing of certain documents . Several factors affect witnesses ' credibility . A credible witness is `` competent to give evidence , and is worthy of belief . '' Generally , a witness is deemed to be credible if they are recognized ( or can be recognized ) as a source of reliable information about someone , an event , or a phenomenon . |
Culex | Culex is a genus of mosquitoes , several species of which serve as vectors of one or more important diseases of birds , humans and other animals . The diseases they vector include arbovirus infections such as West Nile virus , Japanese encephalitis , or St. Louis encephalitis , but also filariasis , and avian malaria . They occur worldwide except for the extreme northern parts of the temperate zone , and are the most common form of mosquito encountered in some major US cities such as Los Angeles . |
Coral | Corals are marine invertebrates in the class Anthozoa of phylum Cnidaria . They typically live in compact colonies of many identical individual polyps . The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton . A coral `` group '' is a colony of myriad genetically identical polyps . Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in length . A set of tentacles surround a central mouth opening . An exoskeleton is excreted near the base . Over many generations , the colony thus creates a large skeleton that is characteristic of the species . Individual heads grow by asexual reproduction of polyps . Corals also breed sexually by spawning : polyps of the same species release gametes simultaneously over a period of one to several nights around a full moon . Although some corals can catch small fish and plankton using stinging cells on their tentacles , most corals obtain the majority of their energy and nutrients from photosynthetic unicellular dinoflagellates in the genus Symbiodinium that live within their tissues . These are commonly known as zooxanthellae and the corals that contain them are zooxanthellate corals . Such corals require sunlight and grow in clear , shallow water , typically at depths shallower than 60 m. Corals are major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters , such as the enormous Great Barrier Reef off the coast of Queensland , Australia . Other corals do not rely on zooxanthellae and can live in much deeper water , with the cold-water genus Lophelia surviving as deep as 3000 m . Some have been found on the Darwin Mounds , north-west of Cape Wrath , Scotland . Corals have also been found as far north as off the coast of Washington State and the Aleutian Islands . |
Continental_margin | The continental margin is one of the three major zones of the ocean floor , the other two being deep-ocean basins , and mid-ocean ridges . The continental margin is the shallow water area found in proximity to continent . The continental margin consists of three different features : the continental rise , the continental slope , and the continental shelf . Continental margins constitute about 28 % of the oceanic area . -LSB- 1 -RSB- The continental shelf is the portion of the continental margin that transitions from the shore out towards to ocean . They are believed to make up 7 percent of the sea floor . The width of continental shelves worldwide varies from a 30 meters to 1500 kilometers . It is generally flat , and ends at the shelf break , where there is a drastic increase in slope angle . The mean slope of continental shelves worldwide is 0 ° 07 ' degrees , and typically steeper closer to the coastline than it is near the shelf break . At the shelf break begins the continental slope , which can be one to five kilometers above the deep-ocean floor . The continental slope often exhibits features called submarine canyons . Submarine canyons often cut into the continental shelves deeply , with near vertical slopes , and continue to cut the morphology to the abyssal plain . The valleys are often V-shaped , and can sometime enlarge onto the continental shelf . At the base of the continental slope , there is a sudden decrease in slope , and the sea floor begins to level out towards the abyssal plain . This portion of the seafloor is called the continental rise , and marks the end of the continental margin . |
Coral_Sea | The Coral Sea is a marginal sea of the South Pacific off the northeast coast of Australia , and classified as an interim Australian bioregion . The Coral Sea extends 2,000 km down the Australian northeast coast . It is bounded in the west by the east coast of Queensland , thereby including the Great Barrier Reef , in the east by Vanuatu ( formerly the New Hebrides ) and by New Caledonia , and in the northeast approximately by the southern extremity of the Solomon Islands . In the northwest , it reaches to the south coast of eastern New Guinea , thereby including the Gulf of Papua . It merges with the Tasman Sea in the south , with the Solomon Sea in the north and with the Pacific Ocean in the east . On the west , it is bounded by the mainland coast of Queensland , and in the northwest , it connects with the Arafura Sea through the Torres Strait . The sea is characterised by its warm and stable climate , with frequent rains and tropical cyclones . It contains numerous islands and reefs , as well as the world 's largest reef system , the Great Barrier Reef ( GBR ) , which was declared a World Heritage Site by UNESCO in 1981 . All previous oil exploration projects were terminated at the GBR in 1975 , and fishing is restricted in many areas . The reefs and islands of the Coral Sea are particularly rich in birds and aquatic life and are a popular tourist destination , both nationally and internationally . |
Cosmic_ray | Cosmic rays are high-energy radiation , mainly originating outside the Solar System . Upon impact with the Earth 's atmosphere , cosmic rays can produce showers of secondary particles that sometimes reach the surface . Composed primarily of high-energy protons and atomic nuclei , they are of mysterious origin . Data from the Fermi Space Telescope ( 2013 ) have been interpreted as evidence that a significant fraction of primary cosmic rays originate from the supernovae explosions of stars . Active galactic nuclei probably also produce cosmic rays . |
Continent | A continent is one of several very large landmasses on Earth . Generally identified by convention rather than any strict criteria , up to seven regions are commonly regarded as continents . Ordered from largest in size to smallest , they are : Asia , Africa , North America , South America , Antarctica , Europe , and Australia . In geology , areas of continental crust include regions covered with water . Islands are frequently grouped with a neighbouring continent to divide all the world 's land into geopolitical regions . Under this scheme , most of the island countries and territories in the Pacific Ocean are grouped together with the continent of Australia to form a geopolitical region called Oceania . |
Corvidae | Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows , ravens , rooks , jackdaws , jays , magpies , treepies , choughs , and nutcrackers . In common English , they are known as the crow family , or , more technically , corvids . Over 120 species are described . The genus Corvus , including the jackdaws , crows , and ravens , makes up over a third of the entire family . They are considered the most intelligent of the birds , and among the most intelligent of all animals , having demonstrated self-awareness in mirror tests ( European magpies ) and tool-making ability ( crows , rooks ) -- skills until recently regarded as solely the province of humans and a few other higher mammals . Their total brain-to-body mass ratio is equal to that of great apes and cetaceans , and only slightly lower than in humans . They are medium to large in size , with strong feet and bills , rictal bristles , and a single moult each year ( most passerines moult twice ) . Corvids are found worldwide except for the tip of South America and the polar ice caps . The majority of the species are found in tropical South and Central America , southern Asia and Eurasia , with fewer than 10 species each in Africa and Australasia . The genus Corvus has re-entered Australia in relatively recent geological prehistory , with five species and one subspecies there . Several species of raven have reached oceanic islands , and some of these species are now highly threatened with extinction or have already gone extinct . |
Cyanobacteria | Cyanobacteria -LSB- saɪˌænoʊbækˈtɪəriə -RSB- , also known as Cyanophyta , is a phylum of bacteria that obtain their energy through photosynthesis , and are the only photosynthetic prokaryotes able to produce oxygen . The name `` cyanobacteria '' comes from the color of the bacteria ( κυανός ( kyanós ) = blue ) . Cyanobacteria used to be incorrectly called blue-green algae , but being prokaryotes , the term `` algae '' in modern usage refers to eukaryotes . Like other prokaryotes , cyanobacteria have no membrane-sheathed organelles . Photosynthesis is performed in distinctive folds in the outer membrane of the cell ( unlike green plants which use chloroplasts for this purpose ) . Biologists commonly agree that chloroplasts found in eukaryotes have their ancestry in cyanobacteria , via a process called endosymbiosis . By producing oxygen as a byproduct of photosynthesis , cyanobacteria are thought to have converted the early oxygen-poor , reducing atmosphere , into an oxidizing one , causing the `` rusting of the Earth '' and the Great Oxygenation Event , that dramatically changed the composition of life forms and led to the near-extinction of anaerobic organisms . Cyanobacteria are thought to eventually have evolved into plastids found in eukaryotic plants , which later differentiated into specialized organelles like the etioplast , leucoplast and the chloroplast . |
Coriolis_frequency | The Coriolis frequency ƒ , also called the Coriolis parameter or Coriolis coefficient , is equal to twice the rotation rate Ω of the Earth multiplied by the sine of the latitude φ . The rotation rate of the Earth ( Ω = 7.2921 × 10 − 5 rad/s ) can be calculated as 2π / T radians per second , where T is the rotation period of the Earth which is one sidereal day ( 23 hr 56 m 4.1 s ) . In the midlatitudes , the typical value for is about 10 − 4 rad/s . Inertial oscillations on the surface of the earth have this frequency . These oscillations are the result of the Coriolis effect . Consider a body ( for example a fixed volume of atmosphere ) at latitude moving at velocity in the earth 's rotating reference frame . In the local reference frame of the body , the vertical direction is parallel to the radial vector pointing from the center of the earth to the location of the body and the horizontal direction is perpendicular to this vertical direction ( and hence in the meridional direction ) . The Coriolis force ( proportional to ) , however , is perpendicular to the plane containing both the earth 's angular velocity vector ( where ) and the body 's own velocity in the rotating reference frame . Thus , the Coriolis force is always at an angle with the local vertical direction . The local horizontal direction of the Coriolis force is thus . This force acts to move the body along longitudes or in the meridional directions . Suppose the body is moving with a velocity such that the centripetal and Coriolis ( due to ) forces on it are balanced . We then have where is the radius of curvature of the path of object ( defined by ) . Replacing we obtain Thus the Coriolis parameter , , is the angular velocity or frequency required to maintain a body at a fixed circle of latitude or zonal region . If the Coriolis parameter is large , the effect of the earth 's rotation on the body is significant since it will need a larger angular frequency to stay in equilibrium with the Coriolis forces . Alternatively , if the Coriolis parameter is small , the effect of the earth 's rotation is small since only a small fraction of the centripetal force on the body is canceled by the Coriolis force . Thus the magnitude of strongly affects the relevant dynamics contributing to the body 's motion . These considerations are captured in the nondimensionalized Rossby number . In stability calculations , the rate of change of along the meridional direction becomes significant . This is called the Rossby parameter and is usually denoted where is the in the local direction of increasing meridian . This parameter becomes important , for example , in calculations involving Rossby waves . |
Correlation_and_dependence | In statistics , dependence or association is any statistical relationship , whether causal or not , between two random variables or bivariate data . Correlation is any of a broad class of statistical relationships involving dependence , though in common usage it most often refers to the extent to which two variables have a linear relationship with each other . Familiar examples of dependent phenomena include the correlation between the physical statures of parents and their offspring , and the correlation between the demand for a product and its price . Correlations are useful because they can indicate a predictive relationship that can be exploited in practice . For example , an electrical utility may produce less power on a mild day based on the correlation between electricity demand and weather . In this example , there is a causal relationship , because extreme weather causes people to use more electricity for heating or cooling . However , in general , the presence of a correlation is not sufficient to infer the presence of a causal relationship ( i.e. , correlation does not imply causation ) . Formally , random variables are dependent if they do not satisfy a mathematical property of probabilistic independence . In informal parlance , correlation is synonymous with dependence . However , when used in a technical sense , correlation refers to any of several specific types of relationship between mean values . There are several correlation coefficients , often denoted ρ or r , measuring the degree of correlation . The most common of these is the Pearson correlation coefficient , which is sensitive only to a linear relationship between two variables ( which may be present even when one variable is a nonlinear function of the other ) . Other correlation coefficients have been developed to be more robust than the Pearson correlation -- that is , more sensitive to nonlinear relationships . Mutual information can also be applied to measure dependence between two variables . |
Cosmic_microwave_background | The cosmic microwave background ( CMB ) is electromagnetic radiation left over from an early stage of the universe in Big Bang cosmology . In older literature , the CMB is also variously known as cosmic microwave background radiation ( CMBR ) or `` relic radiation '' . The CMB is a faint cosmic background radiation filling all space that is an important source of data on the early universe because it is the oldest light in the universe , dating to the epoch of recombination . With a traditional optical telescope , the space between stars and galaxies ( the background ) is completely dark . However , a sufficiently sensitive radio telescope shows a faint background noise , or glow , almost isotropic , that is not associated with any star , galaxy , or other object . This glow is strongest in the microwave region of the radio spectrum . The accidental discovery of the CMB in 1964 by American radio astronomers Arno Penzias and Robert Wilson was the culmination of work initiated in the 1940s , and earned the discoverers the 1978 Nobel Prize in Physics . The discovery of CMB is landmark evidence of the Big Bang origin of the universe . When the universe was young , before the formation of stars and planets , it was denser , much hotter , and filled with a uniform glow from a white-hot fog of hydrogen plasma . As the universe expanded , both the plasma and the radiation filling it grew cooler . When the universe cooled enough , protons and electrons combined to form neutral hydrogen atoms . These atoms could no longer absorb the thermal radiation , and so the universe became transparent instead of being an opaque fog . Cosmologists refer to the time period when neutral atoms first formed as the recombination epoch , and the event shortly afterwards when photons started to travel freely through space rather than constantly being scattered by electrons and protons in plasma is referred to as photon decoupling . The photons that existed at the time of photon decoupling have been propagating ever since , though growing fainter and less energetic , since the expansion of space causes their wavelength to increase over time ( and wavelength is inversely proportional to energy according to Planck 's relation ) . This is the source of the alternative term relic radiation . The surface of last scattering refers to the set of points in space at the right distance from us so that we are now receiving photons originally emitted from those points at the time of photon decoupling . Precise measurements of the CMB are critical to cosmology , since any proposed model of the universe must explain this radiation . The CMB has a thermal black body spectrum at a temperature of . The spectral radiance dEν / dν peaks at 160.23 GHz , in the microwave range of frequencies . The photon energy of CMB photons is about 6.626534 × 10-4 eV . Alternatively , if spectral radiance is defined as dEλ / dλ , then the peak wavelength is 1.063 mm . The glow is very nearly uniform in all directions , but the tiny residual variations show a very specific pattern , the same as that expected of a fairly uniformly distributed hot gas that has expanded to the current size of the universe . In particular , the spectral radiance at different angles of observation in the sky contains small anisotropies , or irregularities , which vary with the size of the region examined . They have been measured in detail , and match what would be expected if small thermal variations , generated by quantum fluctuations of matter in a very tiny space , had expanded to the size of the observable universe we see today . This is a very active field of study , with scientists seeking both better data ( for example , the Planck spacecraft ) and better interpretations of the initial conditions of expansion . Although many different processes might produce the general form of a black body spectrum , no model other than the Big Bang has yet explained the fluctuations . As a result , most cosmologists consider the Big Bang model of the universe to be the best explanation for the CMB . The high degree of uniformity throughout the observable universe and its faint but measured anisotropy lend strong support for the Big Bang model in general and the ΛCDM ( `` Lambda Cold Dark Matter '' ) model in particular . Moreover , the fluctuations are coherent on angular scales that are larger than the apparent cosmological horizon at recombination . Either such coherence is acausally fine-tuned , or cosmic inflation occurred . |
DNA | Deoxyribonucleic acid ( -LSB- diˈɒksiˌraɪboʊnjʊˌkliːɪk , _ - ˌkleɪɪk -RSB- DNA ) is a molecule that carries the genetic instructions used in the growth , development , functioning and reproduction of all known living organisms and many viruses . DNA and RNA are nucleic acids ; alongside proteins , lipids and complex carbohydrates ( polysaccharides ) , they are one of the four major types of macromolecules that are essential for all known forms of life . Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix . The two DNA strands are termed polynucleotides since they are composed of simpler monomer units called nucleotides . Each nucleotide is composed of one of four nitrogen-containing nucleobases -- cytosine ( C ) , guanine ( G ) , adenine ( A ) , or thymine ( T ) -- a sugar called deoxyribose , and a phosphate group . The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next , resulting in an alternating sugar-phosphate backbone . The nitrogenous bases of the two separate polynucleotide strands are bound together , according to base pairing rules ( A with T , and C with G ) , with hydrogen bonds to make double-stranded DNA . The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037 and weighs 50 billion tonnes . In comparison , the total mass of the biosphere has been estimated to be as much as 4 trillion tons of carbon ( TtC ) . DNA stores biological information . The DNA backbone is resistant to cleavage , and both strands of the double-stranded structure store the same biological information . This information is replicated as and when the two strands separate . A large part of DNA ( more than 98 % for humans ) is non-coding , meaning that these sections do not serve as patterns for protein sequences . The two strands of DNA run in opposite directions to each other and are thus antiparallel . Attached to each sugar is one of four types of nucleobases ( informally , bases ) . It is the sequence of these four nucleobases along the backbone that encodes biological information . RNA strands are created using DNA strands as a template in a process called transcription . Under the genetic code , these RNA strands are translated to specify the sequence of amino acids within proteins in a process called translation . Within eukaryotic cells DNA is organized into long structures called chromosomes . During cell division these chromosomes are duplicated in the process of DNA replication , providing each cell its own complete set of chromosomes . Eukaryotic organisms ( animals , plants , fungi , and protists ) store most of their DNA inside the cell nucleus and some of their DNA in organelles , such as mitochondria or chloroplasts . In contrast prokaryotes ( bacteria and archaea ) store their DNA only in the cytoplasm . Within the eukaryotic chromosomes , chromatin proteins such as histones compact and organize DNA . These compact structures guide the interactions between DNA and other proteins , helping control which parts of the DNA are transcribed . DNA was first isolated by Friedrich Miescher in 1869 . Its molecular structure was identified by James Watson and Francis Crick from Cold Spring Harbor Laboratory in 1953 , whose model-building efforts were guided by X-ray diffraction data acquired by Raymond Gosling , who was a post-graduate student of Rosalind Franklin . DNA is used by researchers as a molecular tool to explore physical laws and theories , such as the ergodic theorem and the theory of elasticity . The unique material properties of DNA have made it an attractive molecule for material scientists and engineers interested in micro - and nano-fabrication . Among notable advances in this field are DNA origami and DNA-based hybrid materials . |
Costa_Rica | Costa Rica ( -LSB- kɒstə_ˈriːkə -RSB- -LSB- ˈkosta ˈrika -RSB- ; literally meaning `` Rich Coast '' ) , officially the Republic of Costa Rica ( República de Costa Rica ) , is a country in Central America , bordered by Nicaragua to the north , Panama to the southeast , the Pacific Ocean to the west , the Caribbean Sea to the east , and Ecuador to the south of Cocos Island . It has a population of around 4.5 million , of whom nearly a quarter live in the metropolitan area of the capital and largest city , San José . Costa Rica was sparsely inhabited by indigenous people before coming under Spanish rule in the 16th century . It remained a peripheral colony of the empire until independence as part of the short-lived First Mexican Empire , followed by membership in the United Provinces of Central America , from which it formally declared sovereignty in 1847 . Since then , Costa Rica has remained among the most stable , prosperous , and progressive nations in Latin America . Following a brief civil war , it permanently abolished its army in 1949 , becoming one of only a few sovereign nations without a standing army . Costa Rica is an observing member of the Organisation Internationale de la Francophonie ( OIF ) . The country has consistently performed favourably in the Human Development Index ( HDI ) , placing 69th in the world , among the highest of any Latin American nation . It has also been cited by the United Nations Development Programme ( UNDP ) as having attained much higher human development than other countries at the same income levels , with a better record on human development and inequality than the median of the region . Its rapidly developing economy , once heavily dependent on agriculture , has diversified to include sectors such as finance , pharmaceuticals , and ecotourism . Costa Rica is known for its progressive environmental policies , being the only country to meet all five UNDP criteria established to measure environmental sustainability . It was ranked 42nd in the world , and third in the Americas , in the 2016 Environmental Performance Index , was twice ranked the best performing country in the New Economics Foundation 's ( NEF ) Happy Planet Index , which measures environmental sustainability , and was identified by the NEF as the greenest country in the world in 2009 . Costa Rica officially plans to become a carbon-neutral country by 2021 . In 2012 , it became the first country in the Americas to ban recreational hunting . |
Cotton_gin | A cotton gin is a machine that quickly and easily separates cotton fibers from their seeds , allowing for much greater productivity than manual cotton separation . The fibers are then processed into various cotton goods such as linens , while any undamaged cotton is used largely for textiles like clothing . Seeds may be used to grow more cotton or to produce cottonseed oil . Handheld roller gins had been used in India and then other countries since at earliest 500 CE . The Indian worm-gear roller gin , invented some time around the sixteenth century , has , according to Lakwete , remained virtually unchanged up to the present time . The modern mechanical cotton gin was created by American inventor Eli Whitney in 1793 and patented in 1794 . Whitney 's gin used a combination of a wire screen and small wire hooks to pull the cotton through , while brushes continuously removed the loose cotton lint to prevent jams . It revolutionized the cotton industry in the United States , but also led to the growth of slavery in the American South as the demand for cotton workers rapidly increased . The invention has thus been identified as an inadvertent contributing factor to the outbreak of the American Civil War . Modern automated cotton gins use multiple powered cleaning cylinders and saws , and offer far higher productivity than their hand-powered forebears . The original cotton gin was invented by Eli Whitney in 1793 . Whitney began to work on this project after moving to Georgia in search of work . Given that farmers were desperately searching for a way to make cotton farming profitable , a woman named Catharine Greene provided Whitney with funding to create the first cotton gin . Whitney created two cotton gins : a small one that could be hand cranked and a large one that could be driven by a horse or water power . Thanks to the cotton gin , the amount of raw cotton yielded doubled each decade after 1800 . The creation of the cotton gin also led to the creation of machines designed to spin and weave the fabric , which helped to expand the Industrial Revolution in Western Civilization . |
Dam_failure | A dam is a barrier across flowing water that obstructs , directs or slows down the flow , often creating a reservoir , lake or impoundments . Most dams have a section called a spillway or weir over or through which water flows , either intermittently or continuously , and some have hydroelectric power generation systems installed . Dams are considered `` installations containing dangerous forces '' under International Humanitarian Law due to the massive impact of a possible destruction on the civilian population and the environment . Dam failures are comparatively rare , but can cause immense damage and loss of life when they occur . In 1975 the failure of the Banqiao Reservoir Dam and other dams in Henan Province , China caused more casualties than any other dam failure in history . The disaster killed an estimated 171,000 people and 11 million people lost their homes . |
Copenhagen_Accord | The Copenhagen Agreement is a document that delegates at the 15th session of the Conference of Parties ( COP 15 ) to the United Nations Framework Convention on Climate Change agreed to `` take note of '' at the final plenary on 18 December 2009 . The Accord , drafted by , on the one hand , the United States and on the other , in a united position as the BASIC countries ( China , India , South Africa , and Brazil ) , is not legally binding and does not commit countries to agree to a binding successor to the Kyoto Protocol , whose round ended in 2012 . |
Cosmic_background_radiation | Cosmic background radiation is electromagnetic radiation with no discernible source . The origin of this radiation depends on the region of the spectrum that is observed . One component is the cosmic microwave background . This component is redshifted photons that have freely streamed from an epoch when the Universe became transparent for the first time to radiation . Its discovery and detailed observations of its properties are considered one of the major confirmations of the Big Bang . The discovery ( by chance in 1965 ) of the cosmic background radiation suggests that the early universe was dominated by a radiation field , a field of extremely high temperature and pressure . The Sunyaev -- Zel ` dovich effect shows the phenomena of radiant cosmic background radiation interacting with `` electron '' clouds distorting the spectrum of the radiation . There is also background radiation in the infrared , x-rays , etc. , with different causes , and they can sometimes be resolved into an individual source . See cosmic infrared background and X-ray background . See also cosmic neutrino background and extragalactic background light . |
Cubic_mile_of_oil | The cubic mile of oil ( CMO ) is a unit of energy . It was created by Hew Crane of SRI International to aid in public understanding of global-scale energy consumption and resources . Significant sources of energy include oil , coal , natural gas , nuclear , hydroelectric , and biomass ( primarily the burning of wood ) . Other energy sources include geothermal , wind , photovoltaic , and solar thermal . The various energy units commonly used to measure these sources ( e.g. , joules , BTUs , kilowatt hours , therms ) are only somewhat familiar to the general public , and their relationships can be confusing . These common energy units are sized for everyday activities ( a joule is the energy required to lift a small apple one metre vertically ) . For regional , national , and global scales , larger energy units , such as the exajoule , the billion barrels of oil equivalent ( BBOE ) and the quad are used . Derived by multiplying the small common units by large powers of ten these larger units pose additional conceptual difficulties for many citizens . Crane intended the cubic mile of oil to provide a visualizable scale for comparing the contributions of these diverse energy components as a percentage of total worldwide , energy use . The global economy consumes approximately 30 billion barrels of oil ( 1.26 trillion U.S. gallons or 4.75 trillion litres ) each year . Numbers of this magnitude are difficult to conceive by most people . The volume occupied by one trillion U.S. gallons is about one cubic mile . Crane felt that a cubic mile would be an easier concept for the general public than a trillion gallons . |
Cradle_of_civilization | The cradle of civilization is a term referring to locations where , according to current archaeological data , civilization is understood to have emerged . Current thinking is that there was no single `` cradle '' , but several civilizations that developed independently ; with the Fertile Crescent ( Mesopotamia and Ancient Egypt ) understood to be the earliest . Other civilizations arose in Asia among cultures situated along large river valleys , notably the Indus River in the Indian Subcontinent and the Yellow River and Yangtze River in China . The extent to which there was significant influence between the early civilizations of the Near East and those of East Asia is disputed . Scholars accept that the civilizations of Mesoamerica , mainly in modern Mexico , and Norte Chico in present-day Peru emerged independently from those in Eurasia . Scholars have defined civilization using various criteria such as the use of writing , cities , a class-based society , agriculture , animal husbandry , public buildings , metallurgy , and monumental architecture . The term cradle of civilization has frequently been applied to a variety of cultures and areas , in particular the Ancient Near Eastern Chalcolithic ( Ubaid period ) and Fertile Crescent , Ancient India and Ancient China ( Yellow and Yangtze civilization ) . It has also been applied to ancient Anatolia , the Levant and Iran , and used to refer to culture predecessors -- such as Ancient Greece as the predecessor of Western Civilization -- even when such sites are not understood as an independent development of civilization , as well as within national rhetoric . |
Continental_climate | Continental climates are defined in the Köppen climate classification as having a coldest month mean temperature below -3 C ( 26.6 F ) or 0 ° C depending on which isotherm used for the coldest month and four months above 10 ° C . In the Köppen climate system , Continental climates are bordered to the south by Temperate climates or C climates ( coldest month above 0 C , but below 18 C ) and to the north by Boreal climate or E climates ( only 1 to 3 months with a mean temperature of 50 F ) . Köppen also defined continental climates as having more than 30 days with continuous snowcover on the ground . Continental climates often have a significant annual variation in temperature ( hot summers and cold winters ) . They tend to occur in the middle latitudes ( 40 to 55 north ) , where prevailing winds come from over land , and temperatures are not moderated by bodies of water such as oceans or seas . Continental climates occur mostly in the Northern Hemisphere which has the large landmasses required for this type of climate to develop . Most of northern and northeastern China , eastern and southeastern Europe , and the central and upper eastern United States have this type of climate . In Continental climates , Precipitation tends to be moderate in amount , concentrated mostly in the warmer months . Only a few areas , in the mountains of the Pacific Northwest of North America and in Iran , northern Iraq , adjacent Turkey , Afghanistan , Pakistan , and Central Asia show a winter maximum in precipitation . A portion of the annual precipitation falls as snowfall , and snow often remains on the ground for more than a month . Summers in continental climates can feature thunderstorms and frequent cool temperatures , however summer weather is more stable than winter weather . |
Craton | A craton ( -LSB- pronˈkreɪtɒn -RSB- , -LSB- ˈkrætɒn -RSB- , or -LSB- ˈkreɪtən -RSB- from κράτος kratos `` strength '' ) is an old and stable part of the continental lithosphere , where the lithosphere consists of the Earth 's two topmost layers , the crust and the uppermost mantle . Having often survived cycles of merging and rifting of continents , cratons are generally found in the interiors of tectonic plates . They are characteristically composed of ancient crystalline basement rock , which may be covered by younger sedimentary rock . They have a thick crust and deep lithospheric roots that extend as much as several hundred kilometres into the Earth 's mantle . The term craton is used to distinguish the stable portion of the continental crust from regions that are more geologically active and unstable . Cratons can be described as shields , in which the basement rock crops out at the surface , and platforms , in which the basement is overlaid by sediments and sedimentary rock . The word craton was first proposed by the Austrian geologist Leopold Kober in 1921 as Kratogen , referring to stable continental platforms , and orogen as a term for mountain or orogenic belts . Later authors shortened the former term to kraton and then to craton . Examples of cratons are the North China Craton , the Sarmatian Craton in Russia and Ukraine , the Amazonia Craton in South America , the Kaapvaal Craton in South Africa , the North American or Laurentia Craton , and the Gawler Craton in South Australia . |
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