id	keyword
cjel-5672	dioxide
cjel-5672	carbon
cjel-5672	note
cjel-5672	carbon dioxide
cjel-5672	supra
cjel-5672	energy
cjel-5672	epa
cjel-5672	greenhouse
cjel-5672	coal
cjel-5672	effect
cjel-5672	study
cjel-5672	environmental
cjel-5672	warming
cjel-5672	atmospheric
cjel-5672	temperature
cjel-5672	shale