Columbia subject headings:
Climatic changes--Government policy--United States.
Emissions trading--United States.
Greenhouse gas mitigation--Government policy--United States.
Harvard subject headings:
Climatic changes--Government policy--United States
Emissions trading--United States.
Greenhouse gas mitigation--Government policy--United States.
Princeton subject headings:
Climatic changes--Government policy--United States.
Emissions trading--United States.
Greenhouse gas mitigation--Government policy--United States.