The latest report from the Intergovernmental Panel on Climate Change (IPCC) does not, unfortunately, add much more to the debate on global warming than we already know: the famous threshold of 1.5°C will no doubt be breached in the next decade.
But the IPCC is not intended to recommend political choices: it sounds the alarm without providing the solutions to the problem. It never takes sides on possible measures. At most, it mentions that a carbon price can reduce CO2 emissions, and that it is set too low.
There is no mention on the possibility of interconnecting the emissions markets of different countries (leading to the financing of developing countries' efforts by developed countries) or on the relevance for a club of virtuous countries of a carbon tax at the borders, as currently considered by the European Union - which would potentially have a knock-on effect for the rest of the world.
The IPCC's only significant addition in the last two years has been to insist on the need to invest in adapting to global warming. However, environmental policies around the world have so far failed to effectively address this issue.
This is most evident in the case of tropical cyclones. Even in a country like the United States, efforts are so inadequate that the damage suffered for the same climatic event is 14 times higher than in any other OECD country.
There are many reasons for this: difficulty in coordinating to collectively decide on an investment, especially if it is a question of protecting poor populations, but also poor awareness of the risks or the expectation that the State will, as a last resort, come and compensate the victims in case of damage. A recent study highlights these last two factors by showing that the prospect of the implementation in the future of a land use regulation aimed at reducing construction in flood-prone areas, leads to a sharp increase in building permits in these same areas! And when adaptation decisions are left to private actors, choices are made for actions that protect much too locally (with dikes), increase the risks in the surrounding area, and are less effective than collective action (such as reconstruction of beaches).
Global warming will make this problem even more acute. It is very difficult to translate IPCC scenarios to localized risks - river flooding or coastline retreats. Protections can be put in place, and reinforced at regular intervals, but this encourages the development of activity on the protected areas. There will always be a residual risk that these will prove to be undersized, with even more catastrophic consequences.
It may be preferable to move entire villages to safer areas, which is a costly and politically sensitive solution. The IPCC speaks of the risk of "maladaptation", a notion that is present in the news with the famous "megabasin". The answer is not simple. Some water reservoirs are undoubtedly justified, while others amount to delaying the inevitable, by allowing farmers not to question an outdated production model.
Article published in Les Echos on March 30, 2023
Photo by Justin Wilkens on Unsplash
