Details:

Journal Title:
Earth System Dynamics
Personal Author:
McBride, Laura A. ; Hope, Austin P. ; Canty, Timothy P. ; Bennett, Brian F. ; Tribett, Walter R. ; ... More +
McBride, Laura A. ; Hope, Austin P. ; Canty, Timothy P. ; Bennett, Brian F. ; Tribett, Walter R. ; Salawitch, Ross J. Less -
NOAA Program & Office:
CISESS (Cooperative Institute for Satellite Earth System Studies)
Description:
The sixth phase of the Coupled Model Intercomparison Project (CMIP6) is the latest modeling effort for general circulation models to simulate and project various aspects of climate change. Many of the general circulation models (GCMs) participating in CMIP6 provide archived output that can be used to calculate effective climate sensitivity (ECS) and forecast future temperature change based on emissions scenarios from several Shared Socioeconomic Pathways (SSPs). Here we use our multiple linear regression energy balance model, the Empirical Model of Global Climate (EM-GC), to simulate and project changes in global mean surface temperature (GMST), calculate ECS, and compare to results from the CMIP6 multi-model ensemble. An important aspect of our study is a comprehensive analysis of uncertainties due to radiative forcing of climate from tropospheric aerosols (AER RF) in the EM-GC framework. We quantify the attributable anthropogenic warming rate (AAWR) from the climate record using the EM-GC and use AAWR as a metric to determine how well CMIP6 GCMs replicate human-driven global warming over the last 40 years. The CMIP6 multi-model ensemble indicates a median value of AAWR over 1975–2014 of 0.221°C per decade (range of 0.151 to 0.299°C per decade; all ranges given here are for 5th and 95th confidence intervals), which is notably faster warming than our median estimate for AAWR of 0.157°C per decade (range of 0.120 to 0.195 °C per decade) inferred from the analysis of the Hadley Centre Climatic Research Unit version 5 data record for GMST. Estimates of ECS found using the EM-GC assuming that climate feedback does not vary over time (best estimate 2.33°C; range of 1.40 to 3.57 °C) are generally consistent with the range of ECS of 1.5 to 4.5°C given by the IPCC’s Fifth Assessment Report. The CMIP6 multi-model ensemble exhibits considerably larger values of ECS (median 3.74°C; range of 2.19 to 5.65 °C). Our best estimate of ECS increases to 3.08°C (range of 2.23 to 5.53°C) if we allow climate feedback to vary over time. Given the estimated emission of 11.7 Gt C per year for 2019 due to combustion of fossil fuels and deforestation, our EM-GC simulations suggest that the 1.5°C warming target of the Paris Agreement will not be achieved unless carbon and methane emissions are severely curtailed in the next 10 years.
Keywords:
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Climate Change Climatology Mathematical Models
Source:
Earth Syst. Dynam., 12, 545–579, 2021
DOI:
https://doi.org/10.5194/esd-12-545-2021
Document Type:
Journal Article
Funding:
Grant no. ​NA19NES4320002 ; Grant no. NA14NES4320003
Grant no. ​NA19NES4320002 ; Grant no. NA14NES4320003 Less -
License:
https://creativecommons.org/licenses/by/4.0/
Rights Information:
CC BY
Compliance:
Submitted
Main Document Checksum:
[+]
urn:sha256:81a576051e88bf6ab9dff32378cd51ae9cd602eea6a58c0a8e5680dd5f7d60d2
Download URL:
https://repository.library.noaa.gov/view/noaa/48162/noaa_48162_DS1.pdf
File Type:

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