Protection of the global environment requires the cooperation and action of the United States and the European Union. Both have provided aid to developing countries for sustainable development, but in the past decade the EU has been more generous in helping the world's poor than has the U.S. The Americans and Europeans agreed in the 1990s that they ought to take on a greater share of global environmental burdens and help the developing countries cope with environmental changes. However, the Europeans are now more favorable toward sharing the burdens of environmental change. These mostly different policies are explained in part by different attitudes toward development assistance and contrasting political systems. Although the EU now does more for sustainable development, neither actor does as much as it needs to. However, environmental changes may, in the long run, push them to be more generous in implementing sustainable development at home and abroad. Copyright © 2002 Sage Publications.