Boy, it’s getting really hard to keep up with all these global warming lies errors that are surfacing.  Let’s see…there’s the error in the Intergovernmental Panel on Climate Change (IPCC) report about the melting rate of the Himalayan glaciers; then there’s the manipulation of Russian climate data by British scientists; the coordinated effort to tamp down dissent among scientists, and of course the famous hockey stick fiasco, “mike’s nature trick” and “hiding the decline” of proxy reconstructions. Oh, and who can forget the most recent acknowledgement by an IPCC author that Al Gore’s favorite claim that the world’s scientists have reached a “consensus” that humans are causing global warming was a total fabrication! 

Well, now there’s another gaffe to add to that growing list.  The Economist reports that the Netherlands Environmental Assessment Agency (PBL) this week admitted (in a report published yesterday) that evidence it put into the 3,000-page IPCC report had several factual errors (see the chart below for a list of these errors and the IPCC response).

But The Economist addresses a more serious issue than the individual errors, the IPCC’s tendency to “accentuate the negative.”  

Perhaps the most worrying thing about the PBL report, though, is a rather obvious one about which its authors say little. In all ten of the issues that the PBL categorised as major (the original errors on glaciers and Dutch sea level, and the eight others identified in the report), the impression that the reader gets from the IPCC is more strikingly negative than the impression which would have been received if the underlying evidence base had been reflected as the PBL would have wished, with more precise referencing, more narrow interpretation and less authorial judgment. A large rise in heat related deaths in Australia is mentioned without noting that most of the effect is due to population rather than climate change. A claim about forest fires in northern Asia seems to go further than the evidence referred to-in this case a speech by a politician-would warrant.

The Netherlands look more floodable, Asian glaciers more fragile. A suspicion thus gains ground that the way in which the IPCC sythesises, generalises and checks its findings may systematically favour adverse outcomes in a way that goes beyond just serving the needs of policymakers. Anecdotally, authors bemoan fights to keep caveats in place as chapters are edited, refined and summarised. The PBL report does not prove or indeed suggest systematic bias, and it stresses that it has found nothing that should lead the parliament of the Netherlands, or anyone else, to reject the IPCC’s findings. But the panel set up to look at the IPCC’s workings by Dr Pachauri and Mr Ban should ask some hard questions about systematic tendencies to accentuate the negative.