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 is a result of the greatest market failure the world has seen...We risk damages on a scale larger than the two world wars of the last century.
The scientific evidence is now overwhelming: climate change presents very serious global risks, and it demands an urgent global response.
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.
