A reader suggested that it would be useful to summarize in one place my recent blog posts on mitigation. We aim to please so here goes.

Chris Green, Tom Wigley, and I argued in a commentary in Nature last spring that the IPCC had underestimated the mitigation challenge, which can be here in PDF. That paper received some letters back to Nature which I discussed here. Our argument is consistent with other studies like this one and this one. The chairman of IPCC WGIII for AR5 didn’t much like our paper and subsequently corrected a significant error in his critique. Joe Romm didn’t like it at first, and didn’t understand it, but later started citing it to support his arguments.

Another way to look at the size of the challenge is the magnitude of future carbon free energy that will be needed which leave a sizable gap. The size of the challenge can also be expressed in terms of power plant conversion rates.

Still another way is in terms of the Pacala/Socolow “wedges” which I discuss here and here and here.

If we’ve underestimated the size of the challenge we have also underestimated the costs, perhaps by a lot from a baseline that is already very large.

Not only has the size of the challenge been underestimated, but the leading approach to addressing it — pricing carbon via cap and trade — is doomed to failure. One reason is that people just won’t accept higher energy prices. Another is that cap and trade is subject to all sorts of games, even confirmed by insiders. Experience in Europe has been telling, for the ETS and the CDM (which has policy dynamics we’ve seen before). Events unfolding just this week suggest that cap and trade just can’t work in Europe.

Instead of cap and trade, Chris Green and I have suggested that we should instead focus on a low price on carbon, a tax, to raise revenue to invest in technology. Dan Sarewitz and I have argued that innovation must be at the core of mitigation policy, (PDF) and I have testified before Congress that the costs and benefits of mitigation policy must be temporally aligned (PDF).

A search of the Prometheus archives for carbon, mitigation, or emissions will reveal even more posts.