The US will increasingly see the risks of being left behind, and ten years from now they would have to start worrying about being shut out of markets because their production is dirty.

If you look at all the serious scientists in the world, there is no big disagreement on the basics of this...it would be absolute lunacy to act as if climate change is not occurring.

Looking back, I underestimated the risks. The planet and the atmosphere seem to be absorbing less carbon than we expected, and emissions are rising pretty strongly. Some of the effects are coming through more quickly than we thought then.

Climate change represents the greatest and widest-ranging market failure ever seen

A diet that relies heavily on meat production results in higher emissions than a typical vegetarian diet. Different individuals will make different choices. However, the debate about climate change should not be dumbed down to a single slogan, such as 'give up meat to save the planet.

Failing to curb the impact of climate change could damage the global economy on the scale of the Great Depression or the world wars by spawning environmental devastation that could cost 5 to 20 percent of the world's annual gross domestic product.

The one way of guaranteeing to fail is to assume that we will.