Amartya Sen, Terry Barker and the Stern Report

Terry Barker (Co-ordinating Lead Author, Working Group 3 (Mitigation), Intergovernmental Panel for Climate Change and Director, 4CMR, Cambridge Centre for Climate Change Mitigation Research) responds to Nigel Lawson in a letter to the Financial Times that “the Stern review has been praised by the Nobel Prize-winning economists Kenneth Arrow, Robert Solow, James Mirrlees, Amartya Sen and Joseph Stiglitz“.

Is that true? A well-known quote by Mr Sen on the Stern review: “The stark prospects of climate change and its mounting economic and human costs are clearly brought out in this searching investigation. What is particularly striking is the identification of ways and means of sharply minimizing these penalties through acting right now, rather than waiting for our lives to be overrun by rapidly advancing adversities. The world would be foolish to neglect this strong but strictly time-bound practical message“.

Case closed? Not yet.

Here’s some more in-depth thoughts by Mr Sen: “[…] for the purpose for which the report was solicited, the job that was done […] adequately, and you know to say that whether you can judge whether it’s a good economics report that’s a different issue, its not a good economic question to ask the very specific question […]

As Clive Spash reports, one is left wondering if Mr Sen has read the Stern review, or perhaps just a brief summary. For example, how else could a Nobel Prize in Economics make the mistake of “wrongly refer[ring] to the control benefits as costs and the Report as a cost-effectiveness analysis. This is not a cost-effectiveness analysis as the statement from Stern makes clear“?

The conclusion is: endorsements by famous names are no guarantee of quality.

Actually, such endorsements may mean absolutely nothing, because famous names may be too busy to read what they are endorsing.

And in the case of Amartya Sen and the Stern review, it appears that the former was already convinced enough of the urgency of the climate change issue, not to deem it necessary to read what Stern had actually written.


My feeling is that Terry Barker knows all that very well. The whole polemics with Nigel Lawson would have no meaning, without Barker’s mentioning of “The prospect of climate chaos is alarming but not, I submit, alarmist.”

In other words: the only way the IPCC Co-ordinating Lead Author for the WG3 (Mitigation) is able to justify mitigation, is by talking of the “prospect” (i.e. a future possibility for which no probability is given) of “climate chaos“: a prospect that goes beyond the IPCC’s own WG2 findings.

Comparing that unknowable prospect with the real-and-present evidence of climate change mitigation policies including biofuels being one of the causes of worldwide hunger and unrest, I opt for no mitigation, thank you.