Our analysis shows that, for the extreme hot weather of the recent past, there is virtually no explanation other than climate change. The deadly European heat wave of 2003, the fiery Russian heat wave of 2010 and catastrophic droughts in Texas and Oklahoma last year [2011] can each be attributed to climate change. The odds that natural variability created these extremes are minuscule, vanishingly small. To count on those odds would be like quitting your job and playing the lottery every morning to pay the bills.

We are on the precipice of climate system tipping points beyond which there is no redemption.

I think we have a very brief window of opportunity to deal with climate change. No longer than a decade at most.

...the global surface albedo [surface whiteness] and greenhouse gas changes account for practically the entire global climate change.

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

...99 percent confident that the world really was getting warmer and that there was a high degree of probability that it was due to human-made greenhouse gases.

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.