Philosophy in the IPCC
The Intergovernmental Panel on Climate Change (IPCC)1 is a United Nations body that was created in 1988. Its purpose is to review and assess the science of climate change. The IPCC’s First Assessment Report published in 1990 was instrumental in creating a treaty, the United Nations Framework Convention on Climate Change (UNFCCC), in 1992. Since then the IPCC has produced a sequence of reports that have informed the UNFCCC’s development. The Fifth Assessment Report (AR5) was timed to come out in 2014 to provide the scientific background for the UNFCCC’s 2015 meeting in Paris, at which the widely-acclaimed Paris Agreement was adopted. Because of their authoritative nature and their connection with the UNFCCC, the IPCC’s assessment reports are very influential.
AR5 was the first report in which the IPCC included philosophers as ‘lead authors.’ There were two among more than 800 lead authors. I was one and the other was Lukas Meyer. This chapter recounts my experiences in bringing philosophy to the IPCC and the battle to get philosophical issues connected with climate change well represented in the report. I learned a few lessons that I hope may be useful to other philosophers working in the public domain.
It was, first of all, a grueling experience over three and a half years. I attended a dozen meetings of authors, many of which lasted a week or even longer. I went to meetings in Lima, Changwon (South Korea), Wellington (New Zealand),
Addis Ababa, and Kuala Lumpur, as well as many in Europe. You might wonder why the IPCC sends hundreds of people to distant parts of the world, emitting tons of greenhouse gases on the way. The answer, as I understand it, is that the IPCC has little money of its own. It depends on the generosity of governments to pay for meetings, and therefore goes where it is invited. The travel expenses of most lead authors are paid by their own governments. The British government paid for my travel and offset my emissions. Oxford University gave me some relief from teaching, and I raised a little funding for a research assistant. No author receives any pay.
We produced three drafts of the main report before the final version. This report is huge—over five million words. Each draft was sent to many commentators—both academics and governments. We received over 140,000 comments. We were required to take note of each one and record what we did about it. I alone dealt with 700 comments.
The authors were divided into three ‘working groups,’ and each wrote a volume of the report. A subgroup of each working group then wrote summaries of their volume. They wrote a longish ‘Technical Summary’ and a ‘Summary for Policymakers’ (SPM) of a few dozen pages. The SPM was discussed and edited at a final ‘approval session’ with governments, in an extraordinary process that I shall describe.
Finally, after the three working groups had reported, a small group of authors, including me, wrote a Synthesis Report, which brought together the work of all three groups. It too went through several drafts, requiring many meetings, and it also had its own SPM and approval session.
The IPCC is led by scientists, and its reports are treated as scientific publications. I was regularly referred to as a scientist; I did not mind. The methods came from science. At our first meeting, we were told we should refer only to papers published in peer-reviewed journals. I said that philosophers sometimes write books. The response was that books could be referred to, so long as the publisher was a reputable university press, because that would mean it was peer-reviewed. I said I might want to cite Aristotle. The response was that it was permissible to cite material that had not been peer-reviewed, but special procedures applied to this ‘grey literature’ as it was called. The IPCC wanted to hold a copy at its headquarters in Geneva, in case the contents were questioned. I ignored this rule, and no consequences ensued.
To be fair, the IPCC has good reason to be defensive. The Fourth Assessment Report (AR4) contained the incredible prediction that glaciers in the Himalayas would melt by 2035 (IPCC, 2007, section 10.6.2). This one mistake in the 3000 pages of AR4 did not appear in the core scientific volume contributed by Working Group 1. Nevertheless, it drew an extraordinary amount of criticism when it was discovered. The date of 2035 was taken from an unrefereed publication, and it definitely should not have been.
IPCC reports are supposed simply to review the literature. This is difficult for a philosopher, since our nature is to make arguments rather than report what people have said. I ended up reviewing the subject rather than the literature in the subject. I hope this was a good compromise.