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.
There are 400 coal-powered electric plants in the United States. They generated 30 percent of the nation's electricity last year. Coal was the chief source of electrical generation in 19 states and the second most common source in another nine. Coal is most popular in the East, south of New York. Coal still accounted for at least 50 percent of generation in 13 states.