The concept of securitization is generally associated with the Copenhagen school of security studies, which is generally taken to include Ole WÃ¦ver, Barry Buzan, and a range of other, more loosely associated, researchers.
Average annual number of employed coal miners in the United States, 1890-2014. US employment in coal mining peaked in 1923, when there were 863,000 coal miners. Since then, mechanization has greatly improved productivity in coal mining, so that employment has declined at the same time coal production increased. The average number of coal mining employees declined to 65,400 in 2015.
in 1949 a massive blizzard blanketed wyoming killing 17 people 55000 cattle and 105000 sheep wyoming is the leading producer of coal in the united states in 2010 the state produced 40 percent of the nation s total