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.

When it comes to climate, we can all make a big difference.

The presidency is more than a popularity contest.

Our planet has a rising fever. If the crib catches fire you don't say: 'Hmmm, how fast is that crib going to burn? Has it ever burned before? Is my baby flame retardant?'

I'm naturally an optimist, but my basis for hope is rooted in my understanding of human nature.

Each and every one of us can make changes in the way we live our lives and become part of the solution [to climate change]

To use a Southern euphemism, our space program has been snake-bit.