States versus gases.
D002245:Carbon Dioxide / Q000032:analysis*; D003246:Conservation of Energy Resources / Q000331:legislation & jurisprudence*; D035082:Federal Government; D005740:Gases / Q000032:analysis*; D017752:Greenhouse Effect; D011210:Power Plants / Q000331:legislation & jurisprudence; D013219:State Government; D014481:United States
D005740:Gases; D002245:Carbon Dioxide