Measures -- heavily dependent on teamwork and political will -- can slow the rate of global warming and help the world cope with the climate shifts that occur.

Reducing emissions. Burning oil and coal more efficiently, switching to renewable forms of energy, such as solar and wind power, and developing new technologies for industry and transport can attack the problem at the source.

Expanding forests. Trees remove carbon dioxide, the dominant greenhouse gas, from the atmosphere. The more we have, the better. But deforestation -- the current trend -- liberates additional carbon and makes global warming worse.

Changing lifestyles and rules. The cultures and habits of millions of people -- essentially, whether they waste energy or use it efficiently -- have a major impact on climate change. So do government policies and regulations.

Coping. Steps have to be taken -- and the sooner the better -- to limit damage from consequences of global warming that are now inevitable.

Accomplishments to date. . . and problems. A side effect of the painful economic transition in Eastern Europe was a slight fall in greenhouse-gas emissions among the world's major economies between 1990 and 2000. But making more sustained progress will require overcoming a number of obstacles.