What's at risk [in 100 years] if we do not take action, truly is the survival of civilization as we know it... Literally that is the case. We have seen global warming so far of just a little bit less than one degree Celsius and look at what's happened. Superstorm Sandy. Boulder Colorado. All these fires. Hurricane Irene one year before.

The carbon fuels industry-big oil and coal-have a 50-year lease on the Republican Party and they are drilling it for everything it's worth.

The answer is to end our reliance on carbon-based fuels... If we succeed, we create booming new industries, wealth, clean secure energy and maybe we prevent the greatest disaster so far in human history, saving millions of lives while improving billions more. If we fail, basically it's business as usual while things slowly get worse all around us.

If we did not take action to solve this crisis, it could indeed threaten the future of human civilization. That sounds shrill. It sounds hard to accept. I believe it's deadly accurate. But again, we can solve it.

For a long time, the scientists have been telling us global warming increases the temperature of the top layer in the ocean, and that causes the average hurricane to become a lot stronger. So, the fact that the ocean temperatures did go up because of global warming, because of man-made global warming, starting around in the '70s, and then we had a string of unusually strong hurricanes outside the boundaries of this multi-decadal cycle that is a real factor; there are scientists who point that out, and they're right, but we're exceeding those boundaries now.

What changed in the United States with Hurricane Katrina was a feeling that we have entered a period of consequences.

A leapord never changes his stripes.