On IPCC Inaccuracies and Inadequacies
Joe Romm has a great post on his popular Climate Progress blog in which he counters recent criticism that IPCC overestimated the date of Himalayan melting. He accurately mirrors my feelings when he says:
It isn't news that the 2007 projections by the UN Intergovernmental Panel on Climate Change are not accurate. The real news is that the 99% of their "mistakes" are UNDERestimates of likely impacts.Since the IPCC is said to be reviewing evidence regarding this issue, Joe suggests they review all scientific literature regarding sea level rise and ice melt. That would be a good idea but limiting it to only sea level rise and ice melting does not make much sense.
Those of us who have been tracking climate science closely know that if one considers all the evidence that has come to light over the last three years, much of the IPCC edifice would crumble. In fact latest scientific assessments of literature published over this period, such as, The Copenhagen Diagnosis (Nov 2009), Scientific Congress Climate Change (Mar 2009) and to some degree Climate Change Science Compendium (UNEP Sep 2009) have been critical of IPCC.
It's not just sea level rise and ice melt in the poles that have been underestimated in IPCC AR4 projections but its reports are found lacking in several other areas as well.
- Emission growth scenarios - underestimated
- Oceans' capacity as carbon sinks - overestimated
- Methane forcing - underestimated
- Forcing of geological and geomorphological hazards - inadequate
- Tipping elements and general irreversibility of climate change - inadequate
- Emission reduction approach - inadequate
New research and evidence on each of these areas show IPCC projections and its approach to be either deeply conservative or largely inadequate. So yes, IPCC needs to re-analyse evidence regarding the extent of melting in Tibetean-Himalayan glaciers -- the mistake occurred as they included a paper that did not go through the peer-review process, something that is supposed to identify errors such as these.
However, this is more of an exception than the rule. Almost all of IPCC research is based on peer-reviewed research. And as Joe says, most of the time IPCC has made a mistake, it is an underestimate of impacts. The important point is that it is these mistakes, the underestimates, that are much more dangerous than any inaccuracy that turns out to be an overestimate because the former lull our policymakers into thinking they have more time when in fact the time to act is long gone.