Irreversible climate change due to carbon dioxide emissions

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Solomon, Susan, Plattner, Gian-Kasper, Knutti, Reto, Friedlingstein, Pierre
• Other Authors: NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Institute of Biogeochemistry and Pollutant Dynamics ETH Zürich (IBP), Department of Environmental Systems Science ETH Zürich (D-USYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Institute for Atmospheric and Climate Science Zürich (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: dangerous interference; precipitation; sea level rise; warming; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Ice Sheet
• Online Access: https://hal.science/hal-03199260; https://doi.org/10.1073/pnas.0812721106

International audience The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450 – 600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the ‘‘dust bowl’’ era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4 –1.0 m if 21st century CO$_2$ concentrations exceed 600 ppmv and 0.6 –1.9 m for peak CO$_2$ concentrations exceeding ~1,000 ppmv. Additional contributions from glaciersand ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer.