We have at most ten years - not ten years to decide upon action, but ten years to alter fundamentally the trajectory of global greenhouse emissions... We are near a tipping point, a point of no return, beyond which the built in momentum and feedbacks will carry us to levels of climate change with staggering consequences for humanity and all of the residents of this planet.

Jail threats did not dissuade Martin Luther King - and intergenerational justice is a moral issue of comparable magnitude to civil rights.

'Goals' and 'caps' on carbon emissions are practically worthless, if coal emissions continue, because of the exceedingly long lifetime of carbon dioxide in the air.

It has become very difficult for anyone to argue that observed global warming is natural variability. We have good reason for being able to say that the world will be warmer by about a quarter of a degree in the next decade. It's the same reason we had 10 years ago when we said that the 1990s would be warmer than the 1980s: The planet is out of equilibrium.

The scientific excitement in comparing theory with data, and developing some understanding of global changes that are occurring, is what makes all the other stuff worth it.

Talking nice about sun and wind and green jobs is just greenwash.

It would be immoral to leave young people with a climate system spiraling out of control.