I was lucky to grow up at a time when it was not difficult for the child of a tenant farmer to make his way to the state university.

The fact is fossil fuel carbon will stay in the surface climate system for millennia.

The United States did not sign Kyoto, yet its emissions are not that different from the countries that did sign it.

The 5-year mean global temperature has been flat for the last decade, which we interpret as a combination of natural variability and a slow down in the growth rate of net climate forcing.

The climate system is being pushed hard enough that change will become obvious to the man in the street in the next decade.

Coral reefs, the rain forest of the ocean, are home for one-third of the species of the sea. Coral reefs are under stress for several reasons, including warming of the ocean, but especially because of ocean acidification, a direct effect of added carbon dioxide. Ocean life dependent on carbonate shells and skeletons is threatened by dissolution as the ocean becomes more acid.

Several times in Earth's history, rapid global warming occurred, apparently spurred by amplifying feedbacks. In each case, more than half of plant and animal species became extinct. New species came into being over tens and hundreds of thousands of years. But these are time scales and generations that we cannot imagine.