Complementary observational constraints on climate sensitivity

Nathan M. Urban, Klaus Keller

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

A persistent feature of empirical climate sensitivity estimates is their heavy tailed probability distribution indicating a sizeable probability of high sensitivities. Previous studies make general claims that this upper heavy tail is an unavoidable feature of (i) the Earth system, or of (ii) limitations in our observational capabilities. Here we show that reducing the uncertainty about (i) oceanic heat uptake and (ii) aerosol climate forcing can-in principle- cut off this heavy upper tail of climate sensitivity estimates. Observations of oceanic heat uptake result in a negatively correlated joint likelihood function of climate sensitivity and ocean vertical diffusivity. This correlation is opposite to the positive correlation resulting from observations of surface air temperatures. As a result, the two observational constraints can rule out complementary regions in the climate sensitivity-vertical diffusivity space, and cut off the heavy upper tail of the marginal climate sensitivity estimate.

Original languageEnglish (US)
Article numberL04708
JournalGeophysical Research Letters
Volume36
Issue number4
DOIs
StatePublished - Feb 28 2009

Fingerprint

climate
sensitivity
diffusivity
cut-off
estimates
climate forcing
heat
surface temperature
air temperature
aerosols
aerosol
oceans
ocean
air
temperature

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Earth and Planetary Sciences(all)

Cite this

@article{cb728d5545f545b8b14038c7961b9aab,
title = "Complementary observational constraints on climate sensitivity",
abstract = "A persistent feature of empirical climate sensitivity estimates is their heavy tailed probability distribution indicating a sizeable probability of high sensitivities. Previous studies make general claims that this upper heavy tail is an unavoidable feature of (i) the Earth system, or of (ii) limitations in our observational capabilities. Here we show that reducing the uncertainty about (i) oceanic heat uptake and (ii) aerosol climate forcing can-in principle- cut off this heavy upper tail of climate sensitivity estimates. Observations of oceanic heat uptake result in a negatively correlated joint likelihood function of climate sensitivity and ocean vertical diffusivity. This correlation is opposite to the positive correlation resulting from observations of surface air temperatures. As a result, the two observational constraints can rule out complementary regions in the climate sensitivity-vertical diffusivity space, and cut off the heavy upper tail of the marginal climate sensitivity estimate.",
author = "Urban, {Nathan M.} and Klaus Keller",
year = "2009",
month = "2",
day = "28",
doi = "10.1029/2008GL036457",
language = "English (US)",
volume = "36",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "American Geophysical Union",
number = "4",

}

Complementary observational constraints on climate sensitivity. / Urban, Nathan M.; Keller, Klaus.

In: Geophysical Research Letters, Vol. 36, No. 4, L04708, 28.02.2009.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Complementary observational constraints on climate sensitivity

AU - Urban, Nathan M.

AU - Keller, Klaus

PY - 2009/2/28

Y1 - 2009/2/28

N2 - A persistent feature of empirical climate sensitivity estimates is their heavy tailed probability distribution indicating a sizeable probability of high sensitivities. Previous studies make general claims that this upper heavy tail is an unavoidable feature of (i) the Earth system, or of (ii) limitations in our observational capabilities. Here we show that reducing the uncertainty about (i) oceanic heat uptake and (ii) aerosol climate forcing can-in principle- cut off this heavy upper tail of climate sensitivity estimates. Observations of oceanic heat uptake result in a negatively correlated joint likelihood function of climate sensitivity and ocean vertical diffusivity. This correlation is opposite to the positive correlation resulting from observations of surface air temperatures. As a result, the two observational constraints can rule out complementary regions in the climate sensitivity-vertical diffusivity space, and cut off the heavy upper tail of the marginal climate sensitivity estimate.

AB - A persistent feature of empirical climate sensitivity estimates is their heavy tailed probability distribution indicating a sizeable probability of high sensitivities. Previous studies make general claims that this upper heavy tail is an unavoidable feature of (i) the Earth system, or of (ii) limitations in our observational capabilities. Here we show that reducing the uncertainty about (i) oceanic heat uptake and (ii) aerosol climate forcing can-in principle- cut off this heavy upper tail of climate sensitivity estimates. Observations of oceanic heat uptake result in a negatively correlated joint likelihood function of climate sensitivity and ocean vertical diffusivity. This correlation is opposite to the positive correlation resulting from observations of surface air temperatures. As a result, the two observational constraints can rule out complementary regions in the climate sensitivity-vertical diffusivity space, and cut off the heavy upper tail of the marginal climate sensitivity estimate.

UR - http://www.scopus.com/inward/record.url?scp=66149170253&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=66149170253&partnerID=8YFLogxK

U2 - 10.1029/2008GL036457

DO - 10.1029/2008GL036457

M3 - Article

AN - SCOPUS:66149170253

VL - 36

JO - Geophysical Research Letters

JF - Geophysical Research Letters

SN - 0094-8276

IS - 4

M1 - L04708

ER -