On March 20, the IPCC released its sixth report on climate change. This report is even more alarming than the previous ones. By Christian Gollier on atlantico.fr
Christian Gollier: This is a major development, given how cautious this institution has traditionally been. In fact, for a very long time, the IPCC considered its role to be solely that of presenting the scientific truth about the climate and its evolution: the group was not intended to make recommendations on climate policy. Indeed, when you read the 10,000 pages of the three volumes of the Sixth Assessment Report released over the past two years, there is very little discussion of decarbonization policies, and practically nothing about a carbon tax. The fact that the final, definitive report for policymakers includes a recommendation—one that, incidentally, enjoys a consensus in the field of economics—is therefore very good news. This element underscores the importance of encouraging CO2 emitters to take into account the environmental consequences of their actions, and that the best way to achieve this is to implement a carbon tax, as required by the “polluter pays” principle enshrined in our country’s constitution. In this regard, this IPCC report is groundbreaking. Indeed, proposing an increase in carbon prices in order to use the resulting tax revenue to support low-income households represents an unprecedented level of support for this recommendation rooted in economic science.
I’ve already done my part as lead author of the IPCC’s Fourth and Fifth Assessment Reports. I must say that the experience was quite unpleasant from a scientific standpoint. I prefer to present my analysis in my articles and books, with my uncompromising personal commitment. https://t.co/lHR89UYgWU
— Christian Gollier (@CGollier) March 21, 2023
You also point out that «this new IPCC report is still sorely lacking in economic science.» What do you mean by that? How would you explain it?
As I explained earlier, politicians do not want the IPCC to prescribe regulations and climate actions aimed at reducing CO2 emissions through public policy. The IPCC has not been mandated to prescribe solutions. This is clearly evident in the six reports it has produced over the past 30 years, which have gone to great lengths to avoid incorporating economic analyses that are nonetheless essential: measuring the social costs of decarbonization efforts, comparing them with the societal benefits of such decarbonization, or ranking these efforts by merit, given the fact that not all “green” actions are necessarily socially desirable. Economists are scientists interested in improving society to make the world a better place by proposing solutions. Consequently, it is desirable to highlight the paths to achieving this goal, rather than merely stating the facts, as the IPCC does. From now on, the main issue is no longer whether global warming exists, but how to reorganize society—both socially and economically—to address this phenomenon and find concrete solutions at the lowest possible social cost to our fellow citizens. We must define not only the challenges but also the actions required for this transition: who should do what, when, and how? Unfortunately, it must be acknowledged that the IPCC has never truly provided answers to these questions…
The humanities and social sciences are the stepchildren of the IPCC, no doubt for political reasons.
In a way, do you think the IPCC is failing to fulfill its mission?
I wouldn’t go that far, since, scientifically speaking, the report is excellent—particularly in definitively silencing climate skepticism. For the first time, this sixth report clearly states that global warming is caused by human activity. It’s now stated in black and white, and it’s a major historical fact. There’s no longer any room for doubt. Furthermore, the report explains that at our current average rate of CO2 emissions, we’re raising the Earth’s average temperature by a quarter of a degree every 10 years, which is enormous. The situation is grave, and by 2030, we will have crossed the famous 1.5-degree threshold agreed upon at the Paris Conference. Now that this scientific issue has been established, it requires political action. What is deplorable is that, while the real disputes over climate change today are of an economic nature, the IPCC is being asked to look the other way. That is why this call for a carbon tax represents a major political development that should prompt public authorities to shift gears by adopting an effective, transparent, and progressive incentive to decarbonize. The path has been laid out.
