Water Vapor &
Climate Change: New Study Confirms Global Warming Predictions
October 07, 2005 — By University of Miami Rosenstiel School of Marine &
Atmospheric Science
Virginia Key, FL — A new study published in this week’s issue of Science
confirms evidence of global warming using satellite measurements of water vapor
— a well-known greenhouse gas — in the troposphere.
Using satellite measurements of water vapor from 1982 to 2004, Dr. Brian Soden
from the University of Miami Rosenstiel School of Marine & Atmospheric Science
and colleagues were able to confirm the climate model simulations that have long
indicated that moisture is increasing in the upper troposphere and this water
vapor build up is exacerbating global warming. Their findings are published in
the paper, “The Radiative Signature of Upper Tropospheric Moistening.”
“The importance of water vapor in regulating climate is undisputed. It is the
dominant greenhouse gas, trapping more of the Earth’s heat than any other
gaseous constituent,” wrote Soden and his co-authors Darren L. Jackson from the
University of Colorado Cooperative Institute for Research in Environmental
Sciences, V. Ramaswamy and M.D. Schwarzrzkopf from NOAA’s Geophysical Fluid
Dynamics Laboratory, and Xianglei Huang at the Princeton University Atmospheric
and Oceanic Sciences Program.
Water vapor is not only the dominant greenhouse gas, but its concentration also
depends strongly upon temperature. As the climate warms from the burning of
fossil fuels, the concentrations of water vapor are expected to increase. This
moistening of the atmosphere, in turn, absorbs more heat and further raises the
temperature. In this way, water vapor greatly amplifies the global warming
projected to occur over the next century.
In this study, the researchers took satellite observations from the
High-Resolution Infrared Radiometer Sounder (HIRS) to document an increase in
atmospheric water vapor in the upper troposphere – a region of the atmosphere,
which extends from roughly 5-12 km above the surface where the greenhouse effect
from water vapor is particularly potent. The HIRS has been providing global
measurements at consistent time intervals and in the same vapor absorption band
within the troposphere from 1979 to present. The scientists determined that the
concentration of water vapor there has increased over the past 20 years in a
manner consistent with climate model simulations and could double by the end of
the century due to projected increases in other greenhouse gases.
“Up until now, our ability to detect such changes had been limited by inadequate
observational data,” Soden said. “What’s most significant about our research is
that we have identified a distinct characteristic of moistening in the satellite
record. We can now see how the climate’s behavior is consistent with current
models, validating their accuracy and their projections of future global
warming.”
About the Rosenstiel School
Rosenstiel School is part of the University of Miami and, since its founding in
the 1940s, has grown into one of the world’s premier marine and atmospheric
research institutions.
Media Contacts
Ivy Kupec
(305) 421-4704
Annie Reisewitz
305) 284-1601
www.rsmas.miami.edu