.svg)
🤔 What's this IPCC report everyone's talking about?
👉 This is the first part of the new IPCC report (the previous synthesis report dated from 2014), describing our understanding of climate change, its causes as well as its physical consequences. Two further parts will be published by the end of 2022: the second will look at the implications for biodiversity and human societies, as well as adaptation solutions, and the third will describe the state of the art of solutions for combating global warming by limiting emissions and looking ahead to a sustainable future.
🤔 But the IPCC are ideological ecologists, aren't they?
👉 Non : Le rapport est scientifiquement inattaquable. Un travail immense a été réalisé (234 auteurs, 14000 références…). C’est une synthèse exemplaire de la littérature scientifique existante qui permet de dégager un vrai consensus scientifique. Chaque affirmation du rapport est soigneusement pondérée par la confiance qu’ont les auteurs par rapport à cette affirmation (« it is {likely / very likely / extremely likely} that… »). On peut donc lui faire confiance. Ce rapport va bien au-delà des logiques partisanes.
🤔 Is there still any doubt about man's influence on climate change?
👉 No: one of the report's first sentences sets the tone: "It is unequivocal that human influence has warmed the atmosphere, ocean and land. And this is not simply the acceleration of a natural process: the average temperature increases almost linearly with the amount of CO2 emitted by man. We have entered the hottest period in over 100,000 years, and the trend is not about to be reversed.
🤔 What are the anticipated consequences?
👉 The first obvious consequence of climate disruption is a rise in average temperatures. Several scenarios are envisaged depending on the evolution of greenhouse gas emissions, ranging from +1.4°C to +4.4°C in 2100 compared to the pre-industrial period. But beware: these are only average values. This increase is not uniform across regions. In particular, temperature rises in continental and polar zones will be much higher. Furthermore, heat waves are set to intensify. We'll have to wait for the second part of the report to get an idea of the consequences of these developments for our societies, but it's already clear that the changes will be so radical in some regions that we can't simply say that "man will adapt".
Other consequences include a rise in sea levels of between 0.5 and 1 metre by 2100, depending on the scenario. And if we look ahead to 2300, the rise could be as much as 7 meters, or even 15 meters in a scenario that cannot be ruled out. I'll leave you to imagine the consequences. At 7 metres, the island of Noirmoutier has practically disappeared, and only the center of the town of Arles is still emerged. And in some countries, the situation is going to be dramatic.
It should also be noted that global warming is accelerating the water cycle, which will increase rainfall in many regions. But once again, the consequences have to be studied precisely on a region-by-region basis, as in other areas it is drought periods that will intensify.
🤔 But I had a rotten summer! I don't believe any of this.
👉 And yet: the case of France in July and August 2021 is very special, due to an exceptional cold drop meteorological phenomenon. All around us, heat waves have indeed been occurring. There are even fears of a pasta shortage due to the heat wave in Canada and the floods in Europe, which have taken their toll on global durum wheat production.
Furthermore, the IPCC report reminds us that temperature variability over the course of a decade is significant. So beware of false impressions, and keep an eye on general trends and the common good.
🤔 Is it still possible to reverse the trend?
👉 Yes and no. The culprits are known. They are mainly emissions of carbon dioxide, methane and nitrous oxide. Now that we know the correlation between global warming and these emissions, it's easy to deduce a carbon budget that must not be exceeded, depending on the scenario we wish to commit to.
So we know what we have to do: work to reduce these emissions in our activities. The first step is to raise collective awareness. Then, it's up to each and every one of us, whether as individuals or as manufacturers, to work on reducing our own emissions by implementing the following triptych:
1. Measure (Collect all the data needed to accurately calculate our carbon emissions)
2. Analyze (Identify the most significant sources of emissions)
3. Act (Implement and monitor an action plan to reduce emissions).
However, while we can limit the extent of climate change, underlying trends have already begun and are irreversible, particularly in the oceans (rising temperatures, acidification, deoxygenation, etc.). So, whatever we do, the ice caps will continue to melt for centuries, if not millennia, and sea levels will continue to rise. All we can do today is limit the damage. And that's already enormous!
🤔 O kay, fine. I'll have to find out more. How can I do that?
👉 It's out of the question to read the full report (3,949 pages!), which should be seen as encyclopedic content. Numerous summaries are available. The 42-page summary (in English) published by the IPCC is a little technical, but still readable if you have a good command of English. It includes numerous graphs and figures. If you only have five minutes to spare, at least read their 2-page super-summary. Among the French-language sources, special mention goes to BonPote, who has put together a summary accessible to all.
