TY - JOUR
T1 - Estimating the timing of geophysical commitment to 1.5 and 2.0 °C of global warming
AU - Dvorak, M. T.
AU - Armour, K. C.
AU - Frierson, D. M. W.
AU - Proistosescu, C.
AU - Baker, M. B.
AU - Smith, C. J.
N1 - Funding Information:
The authors acknowledge funding from the following sources: National Science Foundation Grant AGS-1752796 (M.T.D., K.C.A.), Alfred P. Sloan Research Fellowship FG-2020-13568 (K.C.A.), NOAA Grant UWSC12184 (C.P.), NERC/IIASA Collaborative Research Fellowship NE/T009381/1 (C.J.S.) and NSF grant AGS-1665247 (D.M.W.F.).
Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2022/6
Y1 - 2022/6
N2 - Following abrupt cessation of anthropogenic emissions, decreases in short-lived aerosols would lead to a warming peak within a decade, followed by slow cooling as GHG concentrations decline. This implies a geophysical commitment to temporarily crossing warming levels before reaching them. Here we use an emissions-based climate model (FaIR) to estimate temperature change following cessation of emissions in 2021 and in every year thereafter until 2080 following eight Shared Socioeconomic Pathways (SSPs). Assuming a medium-emissions trajectory (SSP2–4.5), we find that we are already committed to peak warming greater than 1.5 °C with 42% probability, increasing to 66% by 2029 (340 GtCO2 relative to 2021). Probability of peak warming greater than 2.0 °C is currently 2%, increasing to 66% by 2057 (1,550 GtCO2 relative to 2021). Because climate will cool from peak warming as GHG concentrations decline, committed warming of 1.5 °C in 2100 will not occur with at least 66% probability until 2055.
AB - Following abrupt cessation of anthropogenic emissions, decreases in short-lived aerosols would lead to a warming peak within a decade, followed by slow cooling as GHG concentrations decline. This implies a geophysical commitment to temporarily crossing warming levels before reaching them. Here we use an emissions-based climate model (FaIR) to estimate temperature change following cessation of emissions in 2021 and in every year thereafter until 2080 following eight Shared Socioeconomic Pathways (SSPs). Assuming a medium-emissions trajectory (SSP2–4.5), we find that we are already committed to peak warming greater than 1.5 °C with 42% probability, increasing to 66% by 2029 (340 GtCO2 relative to 2021). Probability of peak warming greater than 2.0 °C is currently 2%, increasing to 66% by 2057 (1,550 GtCO2 relative to 2021). Because climate will cool from peak warming as GHG concentrations decline, committed warming of 1.5 °C in 2100 will not occur with at least 66% probability until 2055.
UR - https://doi.org/10.1038/s41558-022-01372-y
UR - http://www.scopus.com/inward/record.url?scp=85131604368&partnerID=8YFLogxK
U2 - 10.1038/s41558-022-01372-y
DO - 10.1038/s41558-022-01372-y
M3 - Article
SN - 1758-678X
VL - 12
SP - 547
EP - 552
JO - Nature Climate Change
JF - Nature Climate Change
ER -