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

Money has too big an influence on our politics in Washington and somehow we need to do something about that.

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.

The last time the world was three degrees warmer than today-which is what we expect later this century-sea levels were 25m higher. So that is what we can look forward to if we don't act soon.

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.

'Cap and trade' generates special interests, lobbyists, and trading schemes, yielding non-productive millionaires, all at public expense. The public is fed up with such business. Tax with 100% dividend, in contrast, would spur our economy, while aiding the disadvantaged, the climate, and our national security.

If humanity wishes to preserve a planet similar to that on which civilisation developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO₂ will need to be reduced from its current 385 ppm [parts per million] to at most 350 ppm... If the present overshoot of this target CO₂ is not brief, there is a possibility of seeding irreversible catastrophic effects.