Says policy-making requires ambitious short-term goals.

Long-term climate change policy in the United States and abroad is likely to change very slowly, warns an MIT professor who says the lack of future flexibility argues for stronger short-term goals to reduce carbon emissions....

Today's release of a widely anticipated international report on global warming coincides with a growing clamor within the United States to reduce greenhouse gas emissions and prevent the potentially devastating consequences of global climate change. "There's clear evidence that greenhouse gases...