Quizlet is a great flashcard site that helps you create your own flashcards, and provides you with some great ready-made flashcards as well. As an ESL teacher, I find it to be very useful, especially for students who are not native speakers and do not have anybody at home to help them with their vocabulary.
The atmosphere, the ocean, and the terrestrial biosphere. Carbon can be found in the earths oceanic and continental crust in different types of stones as well as in the soil from the decay of organic matter.
2011 carbon dioxide mole fraction in the troposphere. The atmosphere is one of the Earth's major carbon reservoirs and an important component of the global carbon cycle, holding approximately 720 gigatons of carbon. Atmospheric carbon plays an important role in the greenhouse effect. The most important carbon compound in this respect is the gas carbon dioxide (CO 2).