Skip to main content
U.S. flag

An official website of the United States government

Research Highlights

Publication Date
29 November 2012

Identifying Human Influences on Atmospheric Temperature

Print / PDF
Powerpoint Slide
Download Summary Slide
Image
Trends in lower tropospheric temperature over January 1979 to December 2011 in satellite observations (top 2 panels) and in CMIP-5 models. For further details, refer to Fig. 4 in Santer et al. (2013a)
Trends in lower tropospheric temperature over January 1979 to December 2011 in satellite observations (top 2 panels) and in CMIP-5 models. For further details, refer to Fig. 4 in Santer et al. (2013a)
Science

Objective

  • Performs the first multi-model fingerprint study with CMIP-5 simulation output and satellite measurements of stratospheric and tropospheric temperature change

Main scientific points

  • Clearest evidence to date of a human influence on atmospheric temperature
  • Satellite data and CMIP-5 simulations of historical climate change show similar geographical patterns of tropospheric warming and lower stratospheric cooling
  • Sustained, global-scale tropospheric warming and stratospheric cooling cannot be explained by natural internal climate variability
Impact
  • Shows that the identification of a human-caused signal in atmospheric temperature is robust to uncertainties in models and data
  • Maintains DOE’s leadership in fingerprint research
Summary

We find some of the clearest evidence to date of a discernible human influence on atmospheric temperature. Satellite data and computer model simulations of historical climate change show common patterns of pronounced warming of the troposphere and cooling of the lower stratosphere. In the model simulations, these changes are mainly caused by human factors. We show that sustained, global-scale tropospheric warming and lower stratospheric cooling cannot be explained by natural climate variability. Our results are robust to current uncertainties in models and satellite observations.  

Point of Contact
Benjamin Santer
Institution(s)
Lawrence Livermore National Laboratory (LLNL)
Funding Program Area(s)
RGMA
Project(s)
PCMDI – An Earth System Model Evaluation Project
Publication
Identifying Human Influences on Atmospheric Temperature
Santer, Benjamin, Jeffrey Painter, Carl Mears, Charles Doutriaux, Peter Cadwell, Julie M. Arblaster, Philip J. Cameron-Smith, et al. 2012. “Identifying Human Influences On Atmospheric Temperature”. Proceedings Of The National Academy Of Sciences 110: 26-33. doi:10.1073/pnas.1210514109.
Return to top