Lhe idea according to which “we must limit warming to 1.5°C otherwise it is a disaster”, translated into the objective of carbon neutrality in 2050 for all countries, all sectors combined, had the merit of triggering a cycle of alerts, denunciations of inaction and proactive announcements from public authorities. But, faced with implementation delays due to difficulties in engaging actors on the ground, and the growing gap between the display of ambitions and reality, a headwind has arisen to the tune of “no one wants (or cannot) pay the bill.
We must now return to what the Intergovernmental Panel on Climate Change (IPCC) really says to prevent speeches on the climate emergency from raising paralyzing dividing lines (nuclear versus wind, sobriety seen as false nose of austerity, tensions around meat or air flights), or even insinuations on a green dictatorship in the name of the “false science” of the IPCC. In fact, public opinion, which oscillates between eco-anxiety, desire for change and resignation, remains predominantly awaiting credible and ambitious policies.
In its sixth report, the IPCC explains that climate change is already causing substantial damage to ecosystems, human health and food security, and that every additional tenth of a degree counts. It concludes that the overall costs of stabilizing warming at +2°C, which implies carbon neutrality around 2075, are largely justified by the damage avoided.
Cost-benefit ratio
But he does not comment on such a cost-benefit ratio for lower temperature ceilings. In his special 1.5°C report, he indicated, on the other hand, that this objective would require a carbon price aligned with the truth of costs three or four times higher in 2030 than that required by 2°C, i.e. 370 to 500 euros per tonne of carbon in all countries. A shock that poor countries cannot absorb through simple financial transfers, even generous ones. Especially since the average of scenarios at +2°C, like those targeting +1.5°C, give the same temperature peak of +1.7°C, before a return to +1.6°C and + 1.4°C respectively in 2100.
The trap would be to draw from this extreme difficulty in stabilizing warming at +1.5°C a scenario pitting those who want to hold on to 1.5°C to be sure to stay below 2°C, with those who estimate that we still have twenty-five years to avoid exceeding +2°C. But we are not in a negotiation where the unions are asking employers for a 30% increase to obtain 10%!
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