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

A rise of 5C would be a temperature the world has not seen for 30 to 50 million years. We've been around only 100,000 years as human beings. We don't know what that's like.

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

We run enormous risks and we know what kind of reductions of greenhouse gases are necessary to drastically reduce risks. Reducing emissions by half by 2050 is roughly in the right ballpark. It would bring us below 550 ppm.

The scientific evidence is now overwhelming: climate change presents very serious global risks, and it demands an urgent global response.

Adaptation can efficiently reduce the costs of climate change while atmospheric concentrations of greenhouse gases are being stabilised

If coal is going to be used, the only response - because it is the dirtiest of all fuels - is that we have to learn how to do carbon capture and storage and we have to learn how to do it quickly on a commercial scale.