If you still doubt that global warming is real and that humans contribute to it, read the article beginning on page 68. Its author, James Hansen of the NASA Goddard Institute for Space Studies, is no doomsayer. Instead of relying on just computer climate models, which skeptics don't trust, Hansen builds a powerful case for global warming based on the geologic record and simple thermodynamics. He sees undeniable signs of danger, especially from rising ocean levels, but he also believes that we can slow or halt global warming affordably--if we start right away.
Politically, that's the rub. As time slips by, our leverage over the problem melts away. Even small reductions in gas and aerosol emissions today forestall considerable warming and damage in the long run. In our view, the international community needs a leader, but the obvious nation for the job still has its head in the sand.
This article was originally published with the title The Climate Leadership Vacuum.