Contributions of Stratospheric Water Vapor to Decadal Changes in the Rate of Global Warming
Susan Solomon,1
Karen H. Rosenlof,1
Robert W. Portmann,1
John S. Daniel,1
Sean M. Davis,1,2
Todd J. Sanford,1,2
Gian-Kasper Plattner3
Stratospheric water vapor concentrations decreased by about
10% after the year 2000. Here we show that this acted to slow
the rate of increase in global surface temperature over 2000–2009
by about 25% compared to that which would have occurred due
only to carbon dioxide and other greenhouse gases. More limited
data suggest that stratospheric water vapor probably increased
between 1980 and 2000, which would have enhanced the decadal
rate of surface warming during the 1990s by about 30% as compared
to estimates neglecting this change. These findings show that
stratospheric water vapor is an important driver of decadal
global surface climate change.
2 Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA.
3 Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland.
