We created a way of raising standards of living that we can't possibly pass on to our children.

Do believe that if we fail to act in time, it will be the single biggest regret any of us has at the end of our lives.

The world beyond 450 ppm atmospheric concentrations of carbon dioxide, the world that crosses carbon cycle tipping points that quickly take us to 1000 ppm, is a world not merely of endless regional resource wars around the globe. It is a world with dozens of Darfurs. It is a world of a hundred Katrinas, of countless environmental refugees

Protecting dozens of major coastal cities from future flooding will be challenging enough-rebuilding major coastal cities destroyed by super-hurricanes will be an almost impossible task.

When people ask me what they should do, I reply, "Get informed, get outraged, and then get political."

Replacing half of the U.S. ground-transport fuels with hydrogen from wind power by 2050, for example, might require 1,400 gigawatts of advanced wind turbines or more... replacing those fuels with electricity might require less than 400 GW.

Time is short. We have at most a decade to sharply reverse course.