Columbia subject headings:
Climatic changes--Government policy--United States.
Environmental policy--United States.
Greenhouse gases--Government policy--United States.
Harvard subject headings:
Climatic changes--Government policy
Climatic changes--Government policy--United States
Environmental policy--United States
Global warming--Government policy--United States
Greenhouse effect, Atmospheric--Government policy--United States.
Greenhouse gases--Government policy--United States.
Princeton subject headings:
Climatic changes--Government policy--United States.
Environmental policy--United States.
Greenhouse gases--Government policy--United States.