Jul 27, 2007

Identification of human-induced changes in atmospheric moisture content

by
B. D. Santer, C. Mears, F. J. Wentz, K. E. Taylor , P. J. Gleckler, T. M. L. Wigley, T. P. Barnett, J. S. Boyle, W. Brüggemann, N. P. Gillett, S. A. Klein, G. A. Meehl, T. Nozawa, D. W. Pierce, P. A. Stott, W. M. Washington, and M. F. Wehner
,
Proceedings of the National Academy of Sciences
  • States that data from the satellite-based Special Sensor Microwave Imager (SSM/I) show that the total atmospheric moisture content over oceans has increased by 0.41 kg/m2 per decade since 1988
  • States that results from current climate models indicate that water vapor increases of this magnitude cannot be explained by climate noise alone
  • Presents a formal detection and attribution analysis using the pooled results from 22 different climate models
  • Finds the simulated “fingerprint” pattern of anthropogenically caused changes in water vapor is identifiable with high statistical confidence in the SSM/I data
  • Finds that experiments in which forcing factors are varied individually suggest that this fingerprint “match” is primarily due to human-caused increases in greenhouse gases and not to solar forcing or recovery from the eruption of Mount Pinatubo
  • Findings provide preliminary evidence of an emerging anthropogenic signal in the moisture content of earth's atmosphere