- Bishop Hill blog

The IPCC has issued a statement disputing some of the claims about the sexing up of the Summary for Policymakers made in the Mail on Sunday yesterday. This is the guts of it:

The Mail on Sunday also quotes some passages from the Working Group II Summary for Policymakers on migration and refugees, wars and conflicts, famine, and extreme weather, which it claims are “sexed up” from statements in the underlying report. In doing so it misleads the reader by distorting the carefully balanced language of the document.

For instance, the Mail on Sunday quotes the Summary as saying climate change will ‘increase risks of violent conflicts’. In fact the Summary says that climate change can indirectly increase risks of violent conflicts by amplifying factors such as poverty and economic shocks. The Mail on Sunday says the Summary warns of negative impacts on crop yields, with warming responsible for lower yields of wheat, maize, soya and rice. In fact the Summary says that negative impacts of climate change on crop yields have been more common than positive impacts, with wheat and maize yields negatively affected in many regions and effects on rice and soybean yields smaller in major production regions.

The references to the underlying report cited by the Mail on Sunday in contrast to the Summary for Policymakers also give a completely misleading and distorted impression of the report through selective quotation. For instance the reference to “environmental migrants” is a sentence describing just one paper assessed in a chapter that cites over 500 papers – one of five chapters on which the statement in the Summary for Policymakers is based. A quoted sentence on the lack of a strong connection between warming and armed conflict is again taken from the description of just one paper in a chapter that assesses over 600 papers. A simple keyword search shows many references to publications and statements in the report showing the opposite conclusion, and supporting the statement in the Summary that “Climate change can indirectly increase risks of violent conflicts in the form of civil war and inter-group violence…”.

The points in the second paragraph seem to me to fall into the category of "distinctions without a difference". As for the third, I'm not sure why the number of papers cited in the chapter is of any relevance at all - the question is how many papers support the conclusion in the Summary for Policymakers and how many contradict it. Perhaps readers with the time to do so can investigate.

More pertinently, one has to wonder about the wisdom of the IPCC in incorporating woo like this in the report in the first place.

Update on Apr 7, 2014 by

Bishop Hill

Ben Pile has now responded. Having a bit more space to set out his case, I think he makes a very strong case that the Summary for Policymakers is sexed up and I think I see problems here for the reputation of the IPCC's press office:

The [IPCC's] implication here seems to be that there are lots of other papers, cited throughout the chapters, which support the SPM’s claims. If it’s true, it is the IPCC’s problem. I checked the SPM’s claims against the chapter references cited in the SPM. Moreover, if the evidence considered by the WGII is contradictory, the contradictory nature of the evidence should be reflected in the SPM. It wasn’t. We don’t need to think very deeply about why such an evaluation of the evidence was omitted.