Anyone interested in the climate should watch this talk by Professor David Rutledge from Caltech. He makes the argument that there are a lot less recoverable fossil fuels than assumed by just about everyone, including the IPCC emissions scenarios. His conclusion is that even if we burn all the fossil fuels on the planet, atmospheric carbon dioxide will not exceed 500 ppm.

Is he right?  Perhaps, although his analysis considers only conventional fossil fuels and does not take into account unconventional oil sources like tar sands or shale. He also does not consider carbon cycle feedbacks that could also add carbon dioxide to the atmosphere.

If true, it’s undoubtedly good news for the climate but potentially bad news for our society, since it means that we will be seeing the price of energy inexorably rising in the future as competition for remaining energy resources becomes more fierce.

My sense is that, while we can quibble about the numbers, it does seem likely that the IPCC emissions scenarios have overestimated recoverable coal reserves. This suggests that, at the very least, the highest emissions scenarios may be physically impossible to realize.

Grist thanks its sponsors. Become one.