Earths Climate Sensitivity: Apparent Inconsistencies in Recent Assessments
Abstract
Earth's equilibrium climate sensitivity (ECS) and forcing of Earth's climate system over the industrial era have been re-examined in two new assessments: the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), and a study by Otto et al. (2013). The ranges of these quantities given in these assessments and also in the Fourth (2007) IPCC Assessment are analyzed here within the framework of a planetary energy balance model, taking into account the observed increase in global mean surface temperature over the instrumental record together with best estimates of the rate of increase of planetary heat content. This analysis shows systematic differences among the several assessments and apparent inconsistencies within individual assessments. Importantly, the likely range of ECS to doubled CO₂ given in AR5, 1.5–4.5 K/(3.7 W m⁻²) exceeds the range inferred from the assessed likely range of forcing, 1.2–2.9 K/(3.7 W m⁻²), where 3.7 W ⁻² denotes the forcing for doubled CO₂. Such differences underscore the need to identify their causes and reduce the underlying uncertainties. Explanations might involve underestimated negative aerosol forcing, overestimated total forcing, overestimated climate sensitivity, poorly constrained ocean heating, limitations of the energy balance model, or a combination of effects.
- Authors:
-
- Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Univ. of Washington, Seattle, WA (United States)
- NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
- Stockholm Univ. (Sweden)
- Publication Date:
- Research Org.:
- Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1167429
- Report Number(s):
- BNL-107119-2014-JA
Journal ID: ISSN 2328-4277; R&D Project: 2016-BNL-EE630EECA-Budg; KP1701000
- Grant/Contract Number:
- SC00112704
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Earth's Future
- Additional Journal Information:
- Journal Volume: 2; Journal Issue: 12; Journal ID: ISSN 2328-4277
- Publisher:
- American Geophysical Union (AGU)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 54 ENVIRONMENTAL SCIENCES
Citation Formats
Schwartz, Stephen E., Charlson, Robert J., Kahn, Ralph, and Rodhe, Henning. Earths Climate Sensitivity: Apparent Inconsistencies in Recent Assessments. United States: N. p., 2014.
Web. doi:10.1002/2014EF000273.
Schwartz, Stephen E., Charlson, Robert J., Kahn, Ralph, & Rodhe, Henning. Earths Climate Sensitivity: Apparent Inconsistencies in Recent Assessments. United States. https://doi.org/10.1002/2014EF000273
Schwartz, Stephen E., Charlson, Robert J., Kahn, Ralph, and Rodhe, Henning. Mon .
"Earths Climate Sensitivity: Apparent Inconsistencies in Recent Assessments". United States. https://doi.org/10.1002/2014EF000273. https://www.osti.gov/servlets/purl/1167429.
@article{osti_1167429,
title = {Earths Climate Sensitivity: Apparent Inconsistencies in Recent Assessments},
author = {Schwartz, Stephen E. and Charlson, Robert J. and Kahn, Ralph and Rodhe, Henning},
abstractNote = {Earth's equilibrium climate sensitivity (ECS) and forcing of Earth's climate system over the industrial era have been re-examined in two new assessments: the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), and a study by Otto et al. (2013). The ranges of these quantities given in these assessments and also in the Fourth (2007) IPCC Assessment are analyzed here within the framework of a planetary energy balance model, taking into account the observed increase in global mean surface temperature over the instrumental record together with best estimates of the rate of increase of planetary heat content. This analysis shows systematic differences among the several assessments and apparent inconsistencies within individual assessments. Importantly, the likely range of ECS to doubled CO₂ given in AR5, 1.5–4.5 K/(3.7 W m⁻²) exceeds the range inferred from the assessed likely range of forcing, 1.2–2.9 K/(3.7 W m⁻²), where 3.7 W ⁻² denotes the forcing for doubled CO₂. Such differences underscore the need to identify their causes and reduce the underlying uncertainties. Explanations might involve underestimated negative aerosol forcing, overestimated total forcing, overestimated climate sensitivity, poorly constrained ocean heating, limitations of the energy balance model, or a combination of effects.},
doi = {10.1002/2014EF000273},
journal = {Earth's Future},
number = 12,
volume = 2,
place = {United States},
year = {Mon Dec 08 00:00:00 EST 2014},
month = {Mon Dec 08 00:00:00 EST 2014}
}
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Works referenced in this record:
Earth's energy imbalance and implications
journal, January 2011
- Hansen, J.; Sato, M.; Kharecha, P.
- Atmospheric Chemistry and Physics, Vol. 11, Issue 24
On avoiding dangerous anthropogenic interference with the climate system: Formidable challenges ahead
journal, September 2008
- Ramanathan, V.; Feng, Y.
- Proceedings of the National Academy of Sciences, Vol. 105, Issue 38
Climate sensitivity, sea level and atmospheric carbon dioxide
journal, October 2013
- Hansen, James; Sato, Makiko; Russell, Gary
- Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 371, Issue 2001
Twentieth century climate model response and climate sensitivity
journal, January 2007
- Kiehl, Jeffrey T.
- Geophysical Research Letters, Vol. 34, Issue 22
The equilibrium sensitivity of the Earth's temperature to radiation changes
journal, October 2008
- Knutti, Reto; Hegerl, Gabriele C.
- Nature Geoscience, Vol. 1, Issue 11
Reducing the Uncertainties in Direct Aerosol Radiative Forcing
journal, October 2011
- Kahn, Ralph A.
- Surveys in Geophysics, Vol. 33, Issue 3-4
Upward adjustment needed for aerosol radiative forcing uncertainty
journal, March 2014
- Samset, Bjørn H.; Myhre, Gunnar; Schulz, Michael
- Nature Climate Change, Vol. 4, Issue 4
Energy budget constraints on climate response
journal, May 2013
- Otto, Alexander; Otto, Friederike E. L.; Boucher, Olivier
- Nature Geoscience, Vol. 6, Issue 6
An Overview of CMIP5 and the Experiment Design
journal, April 2012
- Taylor, Karl E.; Stouffer, Ronald J.; Meehl, Gerald A.
- Bulletin of the American Meteorological Society, Vol. 93, Issue 4
An Observationally Based Estimate of the Climate Sensitivity
journal, November 2002
- Gregory, J. M.; Stouffer, R. J.; Raper, S. C. B.
- Journal of Climate, Vol. 15, Issue 22
Forcing, feedbacks and climate sensitivity in CMIP5 coupled atmosphere-ocean climate models: CLIMATE SENSITIVITY IN CMIP5 MODELS
journal, May 2012
- Andrews, Timothy; Gregory, Jonathan M.; Webb, Mark J.
- Geophysical Research Letters, Vol. 39, Issue 9
Why Hasn’t Earth Warmed as Much as Expected?
journal, May 2010
- Schwartz, Stephen E.; Charlson, Robert J.; Kahn, Ralph A.
- Journal of Climate, Vol. 23, Issue 10
New estimates of radiative forcing due to well mixed greenhouse gases
journal, July 1998
- Myhre, Gunnar; Highwood, Eleanor J.; Shine, Keith P.
- Geophysical Research Letters, Vol. 25, Issue 14
Evaluating adjusted forcing and model spread for historical and future scenarios in the CMIP5 generation of climate models: FORCING IN CMIP5 CLIMATE MODELS
journal, February 2013
- Forster, Piers M.; Andrews, Timothy; Good, Peter
- Journal of Geophysical Research: Atmospheres, Vol. 118, Issue 3
Earth's energy imbalance and implications
journal, January 2011
- Hansen, J.; Sato, M.; Kharecha, P.
- Atmospheric Chemistry and Physics Discussions, Vol. 11, Issue 9
Works referencing / citing this record:
Beyond equilibrium climate sensitivity
journal, September 2017
- Knutti, Reto; Rugenstein, Maria A. A.; Hegerl, Gabriele C.
- Nature Geoscience, Vol. 10, Issue 10
Analysis algorithm for sky type and ice halo recognition in all-sky images
journal, January 2019
- Boyd, Sylke; Sorenson, Stephen; Richard, Shelby
- Atmospheric Measurement Techniques, Vol. 12, Issue 8
Beyond equilibrium climate sensitivity
text, January 2017
- Knutti, Reto; Rugenstein, Maria A. A.; Hegerl, Gabriele C.
- ETH Zurich
Analysis Algorithm for Sky Type and Ice Halo Recognition in All-Sky Images
posted_content, January 2019
- Boyd, Sylke; Sorenson, Stephen; Richard, Shelby
- Atmospheric Measurement Techniques Discussions