Apr 1, 1998

Detecting climate signals in the surface temperature record

Gerald R. North and Mark J. Stevens
AMS Journal of Climate
  • Applies optimal signal detection theory in a search through 100 yr of surface temperature data for the climate response to four specific radiative forcings
  • Estimates were sought of the strengths of the climate response to solar variability, volcanic aerosols, greenhouse gases, and anthropogenic aerosols
  • Finds that the component of the volcanic response perpendicular to the other signals was very robust and highly significant
  • Finds the component of the greenhouse gas response perpendicular to the others was very robust and highly significant
  • When the sum of all four climate forcings was used, the climate response was more than three standard deviations above the noise level
  • These findings are considered to be powerful evidence of anthropogenically induced climate change