Scientists will say we can't blame global warming for any single event. In a sense that's right, but the fact that the frequency and intensity of these events is increasing you can blame on global warming.

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.

CEOs of fossil energy companies know what they are doing and are aware of long-term consequences of continued business as usual. In my opinion, these CEOs should be tried for high crimes against humanity and nature.

Planet Earth, creation, the world in which civilization developed, the world with climate patterns that we know and stable shorelines, is in imminent peril.

It's as certain that as long as fossil fuels are the cheapest energy, we will just keep burning them.

We have to, in the next ten years, begin to decrease the rate of carbon dioxide emissions and then flatten it out. If that doesn't happen in ten years, we're going to be passing certain tipping points. If the ice sheets begin to disintegrate, what can you do about it? You can't tie a rope around an ice sheet.

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.