1. Measured as the ratio of greenhouse gases (carbon equivalent) emitted per real gross domestic product.
2. See www.whitehouse.gov/news/releases/2002/02/addendum.pdf.
3. Global Climate Change Policy Book: A New Approach (The White House Washington DC 14 February 2002); available at www.whitehouse.gov/news/releases/2002/02/climatechange.html.
4. See http://www.climatevision.gov/.
5. See www.epa.gov/climateleaders.