Global warming is not a “con job.” It is a fact.

This assessment emerged from its research on the mechanisms, still partially unknown, that underpin the climate machine, namely by establishing the largest climate models with its partners (whose outputs directly feed into the conclusions of the IPCC), and by certifying the national observation services that monitor the state of our environments, oceans, ice cover, atmosphere, and mountain slopes.

At the same time, it has also been established that this climate change can be limited. The thousands of scientific publications summarized in the most recent IPCC report notably show that the average global temperature can quickly be stabilised when net CO₂ emissions are reduced to zero.

While today we remain far from such a reduction in emissions of CO₂ and other greenhouse gases, this clear and undeniable scientific assessment means that it is not too late to act and limit climate change, with humanity still able to reverse course. For example, the IPCC has pointed out that “keeping warming to 1.5°C is still possible, but this requires deep, rapid, and sustained greenhouse gas emissions reductions”. In concrete terms, this involves cutting approximately 43% of global CO₂ emissions by 2030 as compared to 2019, and achieving zero net emissions around 2050. Each tenth of a degree that is avoided counts, since “each additional increase in warming heightens risks for health, means of subsistence, food security, water supply, and economic development”. Denying science condemns our economies to more intense shocks, brings the loss of sustainable jobs and rising insecurity, reduces the feasibility of sustainable trajectories, and increases future costs for all societies.

Within this context, but also because adapting to the changes underway is already indispensable, we remain fully mobilized in meeting these challenges alongside all of society and its elected representatives—regional actors in particular—via the Observatories of the Sciences of the Universe.

Authors:

• Nicolas Arnaud, Director of the CNRS’s National Institute of Sciences of the Universe – CNRS Earth & Space
• Jean-François Doussin, CNRS Senior Researcher, Deputy Director of the CNRS’s National Institute of Sciences of the Universe – CNRS Earth & Space
• Gerhard Krinner, CNRS Senior Researcher, Scientific Advisor on Climate-Related Research to management at the CNRS’s National Institute of Sciences of the Universe – CNRS Earth & Space