P. A. Stott, S. F. B. Tett, G. S. Jones, M. R. Allen, W. J. Ingram, J. F. B. Mitchell

Climate Dynamics

Published date January 1, 2001

Attribution of twentieth century temperature change to natural and anthropogenic causes

  • Analyzes possible causes of twentieth century near-surface temperature change
  • Uses an “optimal detection” methodology to compare seasonal and annual data from the coupled atmosphere-ocean general circulation model HadCM2 with observations averaged over a range of spatial and temporal scales
  • The results indicate that the increases in temperature observed in the latter half of the century have been caused by warming from anthropogenic increases in greenhouse gases offset by cooling from tropospheric sulfate aerosols rather than natural variability, either internal or externally forced
  • Finds that greenhouse gases are likely to have contributed significantly to the warming in the first half of the century