The report (IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation) was released yesterday (June 14) and a new controversy has already arisen. Steve McIntyre, over at the 'knowledgable skeptic' blog Climate Audit first identified the problem and defined it in clearly understandable terms here: 1) the 80% figure represents the high end of the most optimistic (ER-2010) scenario and, hence, isn't representative while 2) the ER-2010 scenario was initially published by Greenpeace and the European Renewable Energy Council (here) and its lead author (Sven Teske) also served as one of the lead authors of the IPCC report. In short, there is a clear appearance of impropriety that lead Mark Lynas (author of Six Degrees: Our Future on a Hotter Planet) to conclude that the "renewables report conclusion was dictated by Greenpeace."
There are two major points that need to be fleshed out here. First, the report as a whole is much more reasonable/plausible than the lead from the press release would suggest. Here, for example, is a summary of the report's core finding:
scenarios strongly indicate that RE (renewable energy) will become increasingly important over time, even without but particularly with GHG (green house gas) emissions constraints. However, the resulting contribution of RE in the various studies available in the literature is much lower than their corresponding technical potentials. Moreover, even if substantial growth rates are combined with future RE deployment paths, they are, in general, lower than what has been achieved by the RE industry during the past 10 years.
This is pretty mainstream stuff. In other words, the overall validity of the report has been (legitimately) called into question because of two stupid decisions which may or may not be related: a) the decision to include Teske as a lead author of the report and b) the decision to draw attention to the report by providing a sexy (but pretty obviously misleading) lead -- that close to 80% of global energy supply could come from renewables by 2050.
As for the ER-2010 scenario itself, it is just bad policy analysis. To start with, it presumes economic conditions (e.g. a significant price on carbon, read a cap and trade regime, in place as of 2010) that are already demonstrably false. But this is just the beginning of the problem. As noted by Lynas
How is this (i.e., the 80% reliance on renewables without any increased reliance on nuclear) achieved whilst also reducing carbon emissions at the same time, which is after all the supposed point of the whole exercise? By assuming a totally unrealistic global consumption of energy, with total primary energy use in 2050 actually *less* than the baseline of 2007. The magic trick of getting rid of nuclear whilst generating 80% of the world’s energy from renewables is performed by making an absurd assumption that primary energy use will fall (from 469 exojoules today to 407 in 2050) even as population rises from 7 to 9 billion and GDP per capita more than doubles. I doubt this is even thermodynamically possible, let alone the basis for good policy.
So, there is more going on here than the stupidity of the two decisions described above. Rather than assessing the plausibility of the assumptions that went into the various scenarios and giving them more or less weight accordingly, they seem to have accepted all of them at face value and given them equal weight. Indeed the ER-2010 scenario was one of four picked out for particular attention. The emphasis given to such an obviously flawed scenario indicates an abandonment of the committee's role as scientific assessor of the work.
More on energy tomorrow.
Update: Andrew Revkin just weighed in on the issue.