To me the analogy [to climate change] is... doctors worry a lot about cholesterol. And if you go to the doctor, and the doctor says "oh, your life would be happier if you ate a different diet and exercised" people pay no attention.

Policies that engage us again in the international fight for real climate protection.

The essential thing we need to understand is that the climate crisis is not some future threat, but a very present peril, the biggest one humans have ever encountered. Until we understand that, we'll dawdle.

The most blatant examples are increased power and frequency in hurricanes and the increased depth and frequency of heat waves.

In the States we've had by far the largest demonstrations in the last few years. The largest civil disobedience actions about anything in US history in the last 30 years have all been centred around the climate.

I think fracking for gas will reduce the incentive to turn to renewables, and I think it will do a lot of other damage across the countryside.

In the scientific community, the debate is over, for all intents and purposes, about whether or not the planet is heating and who is causing it. In fact, it's more or less been over since 1995.