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https://doi.org/10.5194/egusphere-2023-1647
https://doi.org/10.5194/egusphere-2023-1647
26 Jul 2023
 | 26 Jul 2023

Opinion: Can uncertainty in climate sensitivity be narrowed further?

Steven Sherwood and Chris Forest

Abstract. After many years with little change in community views on Equilibrium Climate Sensitivity (ECS), in 2021 the IPCC concluded that it was much better known than previously, supported by a major assessment the previous year. This development underpinned increased confidence in long-term climate changes in that report. Here, we place this development in historical context, briefly assess progress since then, and discuss the challenges and opportunities for further improving our knowledge of this iconic concept. We argue that the probability distributions published in those assessments are still approximately valid; while various subsequent studies have claimed further narrowing, they have omitted important structural uncertainties that should be included. The distributions could nonetheless be narrowed in the future, particularly through better understanding of certain climate processes and paleoclimate proxies. Not all touted strategies are truly helpful, however. We also note that as increasingly strong mitigation (i.e., “net-zero”) scenarios are considered, ECS becomes less informative about future climate change compared to other factors such as aerosol radiative forcing, carbon cycle and vegetation processes, and influences on regional change such as ocean dynamics.

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Journal article(s) based on this preprint

29 Feb 2024
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Opinion: Can uncertainty in climate sensitivity be narrowed further?
Steven C. Sherwood and Chris E. Forest
Atmos. Chem. Phys., 24, 2679–2686, https://doi.org/10.5194/acp-24-2679-2024,https://doi.org/10.5194/acp-24-2679-2024, 2024
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Equilibrium climate sensitivity (ECS), with a specific definition, has been used as a convenient...
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The most fundamental parameter used to gauge the severity of future climate change is the...
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