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Meyer and I were in Working Group 3 (WG3), whose job was to investigate the options for ‘mitigation,’ which is to say, reducing the degree of global climate change. We were allocated to Chapter 3 of WG3’s report: a theoretical chapter entitled ‘Social, Economic and Ethical Concepts and Methods.’ We found ourselves working with a dozen other authors who were mostly economists. Later, despite protests from me, I was drafted as an author of the summaries of WG3. This meant I attended WG3’s approval session in Berlin. I also became an author of the Synthesis Report and its SPM. So I saw the AR5 through to its last hurrah at the approval session of the Synthesis Report in Copenhagen.
Even before the authors were recruited, the chapter headings of the working groups’ reports and even their section headings were set by the IPCC Panel itself, which consists of delegates from the 195 member governments. The Panel evidently intended that we two philosophers should be responsible for just one section entitled ‘Justice, Equity and Responsibility.’ Until recently, most of the philosophers who work on climate change have been political philosophers. They have tended to concentrate on how the burden of dealing with climate change should be fairly distributed among countries and people. Who is to blame for it, and who should pay for dealing with it? Given political philosophers’ traditional interest in justice, it was natural for the climate change community to associate philosophy with the topics of justice, equity, and responsibility.
We do indeed have a lot to say about these topics. But we also have a lot to say about the topic of value, which is equally central to climate change. Part of it is the nature of human wellbeing, and how different people’s wellbeing may be aggregated together and weighed against each other. At my request, our working group’s leaders managed to persuade the Panel to add a section to our chapter entitled ‘Values and Wellbeing.’ I took the main responsibility for this section, and Meyer the lead responsibility for ‘Justice, Equity and Responsibility.’
In the space I was given in the WG3 report (IPCC, 2014a, sections 3.4 and 3.6.1), I tried to write a primer on value theory, starting from its foundations. In the practical politics of climate change, it is economists who deliver concrete measurements of value. So my primer worked up from first principles to explaining and criticizing economists’ measurements.
Each step in this development requires heroic assumptions that set aside huge issues. First, we assume that value as a whole can be broken down into separate values. Then we divide values into human and non-human values, and set aside the non-human values. Among human values we concentrate on the wellbeing of individuals, setting aside communal human values, which cannot be ascribed to individuals separately. Then we make some detailed assumptions about how individual wellbeing comes together to determine an aggregate of wellbeing. At this point I included a section on the ethics of population. Since climate change affects the world’s population, population ethics is essential for good judgments about climate change, but until now it had been entirely neglected in the literature of climate change. Finally, we make assumptions that allow us to measure the aggregate of wellbeing in terms of one quantity: money.
To arrive at a credible measure of value in terms of money, quantities of money have to be adjusted to take account of the differing values of money to rich and poor people. Since the time of the great nineteenth-century economist Alfred Marshall (1920, Book 3, Chapter 3), it has been recognized that money is worth less to a rich person than to a poor one because a rich person already has many more of the things money can buy than a poor person has. A rich person has only luxuries to buy, whereas a poor person must buy necessities. Nevertheless, common practice in economic valuation neglects this point. It measures the value of an event or policy in terms of its monetary value overall, making no adjustment for the differing values of money. This common practice is indefensible. Since there is some small chance of correcting it, I stressed this objection in the report. I was even able to carry my objection through to the SPM of WG3, as I shall explain.
Economics has another failing as a means of judging values. It has no way of taking account of non-human values such as the suffering of animals. Economists sometimes assume that the suffering of animals is bad only because it distresses people, so people are willing to pay money to reduce it. This is obviously false, but I am sorry' to say I was not able to give this failing much attention in the report.