By ANDREW C. REVKIN
14 February 2014
(The New York Times) – There’s a noteworthy letter in today’s edition of the journal Science, titled “Global Warming and This Winter’s Cold Weather,” that aims to cut through the flood of overwrought assertions about recent Northern Hemisphere winter weather in the context of global warming.
It’s written by five leading climate scientists, all of whom have long been reliable guides to a complicated and consequential body of science — John M. Wallace at the University of Washington, Isaac M. Held at the Geophysical Fluid Dynamics Laboratory, David W. J. Thompson at Colorado State University, Kevin E. Trenberth at the National Center for Atmospheric Research, and John E. Walsh at the University of Alaska, Fairbanks.
The letter is behind the journal’s subscription wall, so I’m providing excerpts here:[more]
As climate scientists, we share the prevailing view in our community that human-induced global warming is happening and that, without mitigating measures, the Earth will continue to warm over the next century with serious consequences. But we consider it unlikely that those consequences will include more frigid winters.
Distinguishing between different kinds of extreme weather events is important because the risks of different kinds of events are affected by climate change in different ways. For example, a rise in global mean temperature will almost certainly lead to an increase in the incidence of record high temperatures. Global warming also leads to increases in atmospheric water vapor, which increases the likelihood of heavier rainfall events that may cause flooding. Rising temperatures over land lead to increased evaporation, which renders crops more susceptible to drought. As the atmosphere and oceans warm, sea water expands and glaciers and ice sheets melt. In response, global sea level rises, increasing the threat of coastal inundation during storms.