The greatest danger hanging over our children and grandchildren is initiation of changes that will be irreversible on any time scale that humans can imagine.

I've tried to be a straight scientist doing the science and reporting it as best I can.

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.

...99 percent confident that the world really was getting warmer and that there was a high degree of probability that it was due to human-made greenhouse gases.

Coal is the single greatest threat to civilization and all life on our planet.

We're handing them [young people & future generations] a climate system which is potentially out of their control. We're in an emergency: you can see what's on the horizon over the next few decades with the effects it will have on ecosystems, sea level and species extinction

As you get more global warming, you should see an increase in the extremes of the hydrological cycle - droughts and floods and heavy precipitation.