February 9, 2010

Fact checking the IPCC

Wonderful idea -- Bishop Hill chose a paragraph at random from an IPCC report and is proceeding to fact-check it to great amusement. From Bishop Hill:
Pick a paragraph
This was a little experiment that turned up some interesting results. The idea was to pick a paragraph from the IPCC reports and look at its provenance, just to see if anything interesting turned up. It did.

Unfortunately it turned up so much, that I've decided only to analyse the first sentence of the paragraph. I've got a life you know.

Here's the paragraph. It's from WG2, Chapter 10, and its the start of section 10.2.4.1 which is about the effects of climate change on food production.
10.2.4.1 Agriculture and food production
Production of rice, maize and wheat in the past few decades has declined in many parts of Asia due to increasing water stress arising partly from increasing temperature, increasing frequency of El Ni�o and reduction in the number of rainy days (Wijeratne, 1996;Aggarwal et al., 2000; Jin et al., 2001; Fischer et al., 2002; Tao et al., 2003a; Tao et al., 2004). In a study at the International Rice Research Institute, the yield of rice was observed to decrease by 10% for every 1�C increase in growing-season minimum temperature (Peng et al., 2004). A decline in potentially good agricultural land in East Asia and substantial increases in suitable areas and production potentials in currently cultivated land in Central Asia have also been reported (Fischer et al., 2002). Climate change could make it more difficult than it is already to step up the agricultural production to meet the growing demands in Russia (Izrael and Sirotenko, 2003) and other developing countries in Asia.
First step was to look at the citations. I've linked PDFs where I have them.
■Surprisingly for a sentence about rice, maize and wheat Wijeratne 1996 turns out to be about tea production in Sri Lanka.
■I haven't been able to lay my hands on Aggarwal or Jin (I think Aggarwal should actually be Agarwal).
Fischer et al is a study published by an NGO, the Institute for Applied Systems Analysis (IIASA). This body seems to do research into environmental issues. THe study in question appears to be a special report paid for by the UN and as far as I can tell, non-peer reviewed.
■Tao 2003a I can't find
Tao 2004 is a paper on variability in Chinese climate and how various oscillations (ENSO< EASM) affect crops.

So by the end of the first sentence, none of the cited papers that I can lay my hands on support the text as written, namely that "Production of rice, maize and wheat in the past few decades has declined in many parts of Asia".

Some of the reasons for this change became clear when I looked at the Second Order Draft. Here's the equivalent paragraph.
But the science is settled. This is not a sceintific report, this is an agenda-driven text written by a committee that has zero idea of what they are talking about. And our tax dollars are being used to pay for this crap... Posted by DaveH at February 9, 2010 7:27 PM