In assessing the role of countries as polluters, it is useful to look at how much carbon dioxide emit, both overall and on average per citizen. WWF has classified countries based on statistical information contained in the World Resources Institute Yearbook for 1996/7. This relies on data from the Carbon Dioxide Information Analysis Centre for 1992 for "industrial" sources - that is excluding emissions from changes in land-use.

Column 4- This column looks at total emissions in 1992 by country in three groups: 1) the large global polluters (more than 800 million metric tons) scored red; 2) medium polluters (300-800 million metric tons) scored yellow; and 3) low polluters (less than 300 million metric tons) scored green.