Stringent mitigation substantially reduces risk of unprecedented near-term warming rates

• Published in: Nature climate change Vol. 11; no. 2; pp. 126 - 131
• Main Authors: McKenna, Christine M., Maycock, Amanda C., Forster, Piers M., Smith, Christopher J., Tokarska, Katarzyna B.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.02.2021; Nature Publishing Group
• Subjects: 704/106/694; 704/106/694/1108; 704/106/694/2739; 704/106/694/2786; 704/106/694/682; Climate Change; Climate Change/Climate Change Impacts; Climate models; Earth and Environmental Science; Emulators; Environment; Environmental impact; Environmental Law/Policy/Ecojustice; Global temperatures; Global warming; Greenhouse gases; Mean temperatures; Mitigation; Net zero; Paris Agreement; Risk reduction; Stabilizing; Surface temperature; Temperature trends; Variability
• ISSN: 1758-678X; 1758-6798
• DOI: 10.1038/s41558-020-00957-9

Following the Paris Agreement, many countries are enacting targets to achieve net-zero GHG emissions. Stringent mitigation will have clear societal benefits in the second half of this century by limiting peak warming and stabilizing climate. However, the near-term benefits of mitigation are generally thought to be less clear because forced surface temperature trends can be masked by internal variability. Here we use observationally constrained projections from the latest comprehensive climate models and a simple climate model emulator to show that pursuing stringent mitigation consistent with holding long-term warming below 1.5 °C reduces the risk of unprecedented warming rates in the next 20 years by a factor of 13 compared with a no mitigation scenario, even after accounting for internal variability. Therefore, in addition to long-term benefits, stringent mitigation offers substantial near-term benefits by offering societies and ecosystems a greater chance to adapt to and avoid the worst climate change impacts. GHG mitigation is not likely to be detectable in global mean temperature before mid-century. However, a simple climate emulator and an Earth system model ensemble suggest that strong mitigation greatly decreases the likelihood of high rates of 20-year warming over the next two decades.