Sources

http://www.epa.gov/cleanenergy/energy-and-you/affect/coal.html

http://www.cleancoalusa.org/about-us

http://iamtush.files.wordpress.com/2013/01/a-worker-holds-coal-06e19f398cd19199.jpg

http://www.selfbuildinireland.com/wp-content/uploads/2012/11/coal.jpg

http://thegreeneconomy.com/wp-content/uploads/2012/12/coalplug.jpg

http://progressivetimes.files.wordpress.com/2011/09/coal-pollution.jpg