Fundamental Research Division
The DRF at the CEA assemble approximately 6,000 scientists since January 2016.
Scientific result | International | Climatic models | Climate | Impact of climate change
The results converge on the fact that a value below 2°C is barely compatible with the three types of study. The last glacial maximum indicates that values above 4.5°C are not very credible. The results reduce the range of values at 66% chance (the probable range given in the IPCC reports) to 2.6°C - 3.9°C, and the 5% - 95% range of chance to 2.3°C - 4.7°C. The estimates indicate that this range is restricted to an interval of 2°C - 5.7°C.
These results are important in order to realistically target the objectives set by the Paris Agreement. Indeed, this study provides a strong constraint on the lower limit of climate sensitivity. Considerations regarding how to keep the temperature below 2°C or 1.5°C of the Paris Agreement must seriously take into account these results in order to meet the objectives of sustainable development.
It is possible to compare the results from climate models with this new climate sensitivity assessment since it does not use any of their data.
Some of the CMIP6 (Coupled Model Intercomparison Project Phase 6) models that will contribute to the 6th IPCC report producing sensitivities below 2°C appear to underestimate warming. Several new-generation models produce values around 5°C or more. Although they are outside the most likely range, they produce high values that remain possible.
These results were obtained within the framework of the World Climate Research Programme, which was established in 1980 under the joint sponsorship of the World Meteorological Organization and the International Council for Science (ICSU) and, since 1993, the Intergovernmental Oceanographic Commission (IOC) of UNESCO. The paleoclimatic contribution was organized by a group within the Paleoclimate Modelling Intercomparison Project (PMIP) coordinated at the LSCE.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.