The report has a long list of new “technological breakthroughs” (the phrase that it uses) in its Annex C needed to achieve its costs estimates. Does your endorsement of its cost estimates mean that you also accept its assumptions that such breakthroughs are needed?

Also, the report assumes a spontaneous decarbonization of the global economy to 2050 of about 1.8% per year. This takes care of about 53 Gt CO2 in future emissions reductions, more than the 48 Gt it calls for. There is an order-of-magnitude play in the cost estimates as a function of assumptions of energy intensity decline. No one knows the future, but clearly, different assumptions could lead to different results.

None of this is an argument against action, but it is an argument against misleading people with rosy scenarios — if $45 trillion can be called “rosy”.

Second, you write, “the IEA report should serve as a reminder that the challenge of mitigation is significant and costly.” I agree the report Makes clear that the challenge is significant, but I don’t view an extra investment of a mere 1.1% of GDP per year as particularly “costly” — especially given the cost of inaction and the fact that the report makes clear that the extra investment is not a pure “cost” to GDP. Indeed, much of the investment pays for itself in reduced fuel bills. I’m not saying it would be politically easy — obviously it ain’t — but I don’t think the IEA is being “fantastically delusional” either for proposing a strategy and set of solutions similar to what I have proposed.

Third, I guess you see the glass as 80% empty, while I see it as 20% full (and containing the crucial antidote).

http://climateprogress.org/2008/06/08/must-read-iea-report-part-1-act-now-with-clean-energy-or-face-6%c2%b0c-warming-cost-is-not-high-media-blows-the-story/