TY - JOUR
T1 - Changes in IPCC Scenario Assessment Emulators Between SR1.5 and AR6 Unraveled
AU - Nicholls, Z.
AU - Meinshausen, M.
AU - Lewis, Jared
AU - Smith, C. J.
AU - Forster, P. M.
AU - Fuglestvedt, J. S.
AU - Rogelj, J.
AU - Kikstra, J. S.
AU - Riahi, K.
AU - Byers, E.
N1 - Funding Information:
Funding from the European Union's Horizon 2020 research and innovation programme is acknowledged for the following authors and projects (grant agreement number): Z. N., J. L., and J. R. ESM2025—Earth System Models for the Future (101003536); P. M. F. and J. R. CONSTRAIN (820829); J. R. PROVIDE (101003687); J. S. K. and E. B. ENGAGE (821471); K. R. GENIE (European Research Council 951542). C. J. S. was supported by a NERC/IIASA Collaborative Research Fellowship (NE/T009381/1). J. S. K. was supported by the UK Natural Environment Research Council under grant agreement NE/S007415/1.
Publisher Copyright:
© 2022. The Authors.
PY - 2022/10/28
Y1 - 2022/10/28
N2 - The IPCC's scientific assessment of the timing of net-zero emissions and 2030 emission reduction targets consistent with limiting warming to 1.5°C or 2°C rests on large scenario databases. Updates to this assessment, such as between the IPCC's Special Report on Global Warming of 1.5°C (SR1.5) of warming and the Sixth Assessment Report (AR6), are the result of intertwined, sometimes opaque, factors. Here we isolate one factor: the Earth System Model emulators used to estimate the global warming implications of scenarios. We show that warming projections using AR6-calibrated emulators are consistent, to within around 0.1°C, with projections made by the emulators used in SR1.5. The consistency is due to two almost compensating changes: the increase in assessed historical warming between SR1.5 (based on AR5) and AR6, and a reduction in projected warming due to improved agreement between the emulators' response to emissions and the assessment to which it is calibrated.
AB - The IPCC's scientific assessment of the timing of net-zero emissions and 2030 emission reduction targets consistent with limiting warming to 1.5°C or 2°C rests on large scenario databases. Updates to this assessment, such as between the IPCC's Special Report on Global Warming of 1.5°C (SR1.5) of warming and the Sixth Assessment Report (AR6), are the result of intertwined, sometimes opaque, factors. Here we isolate one factor: the Earth System Model emulators used to estimate the global warming implications of scenarios. We show that warming projections using AR6-calibrated emulators are consistent, to within around 0.1°C, with projections made by the emulators used in SR1.5. The consistency is due to two almost compensating changes: the increase in assessed historical warming between SR1.5 (based on AR5) and AR6, and a reduction in projected warming due to improved agreement between the emulators' response to emissions and the assessment to which it is calibrated.
UR - https://doi.org/10.1029/2022GL099788
UR - http://www.scopus.com/inward/record.url?scp=85141743363&partnerID=8YFLogxK
U2 - 10.1029/2022GL099788
DO - 10.1029/2022GL099788
M3 - Article
C2 - 36589268
SN - 0094-8276
VL - 49
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 20
M1 - e2022GL099788
ER -