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.
By IEA the top 10 coal producers in 2011 were (Mt): China 3,576 (46%), United States 1,004 (13%), India 586 (8%), Australia 414 (5%), Indonesia 376 (5%), Russia 334 (4%), South Africa 253 (3%), Germany 189 (2%), Poland 139 (2%) and Kazakhstan 117 (2%).