global warming

+7°C: New scientific projections are alarming

It's gonna get hot!


Global warming is shaping up to be more serious than expected, with the worst-case scenario predicting +7°C in 2100, French scientists warned Tuesday, presenting new and very alarming climate models that will serve as a basis for the IPCC.

In 2021, UN climate experts will unveil their new assessment report on climate change, the sixth since 1990. Around 100 French researchers and engineers, notably from the French National Centre for Scientific Research (CNRS), the French Atomic Energy Commission (CEA) and Météo-France, have worked to develop two climate models that will feed into this work.

According to the newspaper The WorldThis colossal task involved some 100 researchers and engineers who simulated more than 80,000 years of climate change, using supercomputers day and night for a year, requiring 500 million hours of computing time and generating 20 petabytes (20 million billion bytes) of data. These models were then subjected to several socio-economic scenarios.

In the most pessimistic scenario, based on rapid economic growth fuelled by fossil fuels, the rise in global average temperature reaches 6.5 to 7°C in 2100. In the latest IPCC report of 2014, the worst-case scenario predicted +4.8°C compared to the pre-industrial period.

Global warming
Global average temperature change under different scenarios. CNRS

What would this mean concretely for human societies? In France, the multiplication of heat waves is a good example, the scientists replied at a press conference. The 2003 heat wave, which killed 15,000 people in France and more than 70,000 in Europe, would become the norm by the 2050s.

This would be accompanied by "much longer and more extensive droughts", "from 2070 onwards, a Garonne will be dry for a few months", "agricultural practices that have been heavily questioned", "forest fires that are multiplying in regions where they are not too frequent today", listed David Salas y Mélia, a climatologist researcher and climate manager at the CNRM research centre (Météo-France-CNRS).

Why not enjoy unlimited reading of UP'? Subscribe from €1.90 per week.

Scientists have also subjected their climate models to alternative scenarios. The most optimistic one, based on strong international cooperation and the priority given to sustainable development, would "just" allow us to stay below the 2°C warming target and "at the cost of temporarily exceeding the 2°C target during the century". This scenario implies an immediate decrease in CO2 emissions, global carbon neutrality by 2060 and a capture of atmospheric CO2 in the order of 10 to 15 billion tonnes per year by 2100, which is technically uncertain.

Act Now

The 2015 Paris Climate Accord calls for limiting global warming to well below 2°C or even 1.5°C. The world is not moving in this direction, since the commitments made by States to date would lead to a warming of 3°C. UN Secretary-General Antonio Guterres called a summit in New York on Monday to call on world leaders to raise their ambitions.

The average global temperature at the end of the century is highly dependent on the climate policies that will be implemented now and throughout the 21st century. "CNRS, Météo-France and CEA insist in their presentation.

This news is all the more worrying since these new climate models developed by the CNRM and the Parisian Institute Simon Laplace are more reliable and more refined than the previous ones. « There is a qualitative leap in model results ", insisted Pascale Braconnot, climate modeling specialist at the Laboratoire des sciences du climat et de l'environnement. Other foreign models that have already been made public, and which will also be used by the IPCC, also point towards a more pronounced warming. « This could be explained by a stronger response of the climate to anthropogenic greenhouse gas increases than in the 2012 simulations, but the reasons for this increased sensitivity and the degree of confidence to be placed in it remain to be assessed. ", according to the presentation.

Thanks to this finer scale, researchers have better modelled the consequences of global warming in Western Europe for heat waves, but also on the evolution of the Arctic ice pack, which could disappear or almost disappear in summer by the end of the century.

Nous avons un message pour vous…

Dès sa création, il y a plus de dix ans,  nous avons pris l’engagement que UP’ Magazine accordera au dérèglement climatique, à l’extinction des espèces sauvages, à la pollution, à la qualité de notre alimentation et à la transition écologique l’attention et l’importance urgentes que ces défis exigent. Cet engagement s’est traduit, en 2020, par le partenariat de UP’ Magazine avec Covering Climate Now, une collaboration mondiale de 300 médias sélectionnés pour renforcer la couverture journalistique des enjeux climatiques. En septembre 2022, UP’ Magazine a adhéré à la Charte pour un journalisme à la hauteur de l’urgence écologique.

Nous promettons de vous tenir informés des mesures que nous prenons pour nous responsabiliser à ce moment décisif de notre vie. La désinformation sur le climat étant monnaie courante, et jamais plus dangereuse qu’aujourd’hui, il est essentiel que UP’ Magazine publie des rapports précis et relaye des informations faisant autorité – et nous ne resterons pas silencieux.

Notre indépendance éditoriale signifie que nous sommes libres d’enquêter et de contester l’inaction de ceux qui sont au pouvoir. Nous informerons nos lecteurs des menaces qui pèsent sur l’environnement en nous fondant sur des faits scientifiques et non sur des intérêts commerciaux ou politiques. Et nous avons apporté plusieurs modifications importantes à notre expression éditoriale pour que le langage que nous utilisons reflète fidèlement, mais sans catastrophisme, l’urgence écologique.

UP’ Magazine estime que les problèmes auxquels nous sommes confrontés dans le cadre de la crise climatique sont systémiques et qu’un changement sociétal fondamental est nécessaire. Nous continuerons à rendre compte des efforts des individus et des communautés du monde entier qui prennent courageusement position pour les générations futures et la préservation de la vie humaine sur terre. Nous voulons que leurs histoires inspirent l’espoir.

Nous espérons que vous envisagerez de nous soutenir aujourd’hui. Nous avons besoin de votre soutien pour continuer à offrir un journalisme de qualité, ouvert et indépendant. Chaque abonnement des lecteurs, quelle que soit sa taille, est précieux. Soutenez UP’ Magazine à partir d’1.90 € par semaine seulement – et cela ne prend qu’une minute. Merci de votre soutien.

Je m’abonne →

Inline Feedbacks
View all comments
The urgency of adapting to the climate emergency
Previous article

The urgency of adapting to the climate emergency

Next article

[Grand Reporter] Without faith or law, travel to the heart of the burning Amazon...

Latest articles from Climate



Already registered? I'm connecting

Inscrivez-vous et lisez three articles for free. Recevez aussi notre newsletter pour être informé des dernières infos publiées.

→ Register for free to continue reading.



You have received 3 free articles to discover UP'.

Enjoy unlimited access to our content!

From $1.99 per week only.