Cooperative Institute for Research in Environmental Sciences

A world of change: Climate yesterday, today, and tomorrow

Susan Solomon

Earth System Research Laboratory
National Oceanic and Atmospheric Administration
Boulder, Colorado

The first part of this talk summarizes key evidence from the 2007 report of the Intergovernmental Panel on Climate Change for changes in the Earth's climate, and the causes of those changes. Understanding how temperatures are increasing around the world, how ice is melting at the poles, and how rain is decreasing in key regions, are among the issues that will be addressed. Observations of the greenhouse gases and aerosols that are the main reasons for current climate change will also be discussed. The second part of the talk reviews findings that were not detailed in IPCC on the subject of the time scales of climate changes due to carbon dioxide increases. It is not generally appreciated that man-made warming that takes place due to increases in carbon dioxide concentration is nearly irreversible for more than 1000 years after emissions stop. This is due to physical linkages between transport of heat and of carbon dioxide to the deep ocean, rendering the cumulative effects of every year's carbon dioxide emissions and resulting climate changes unique among major anthropogenic greenhouse gases. Illustrative impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 ppmv to a peak of 450-600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the 'dust bowl' era, as well as a lower limit to slow but inexorable sea level rise that could eventually exceed 1 meter.

About the Lecturer
Susan Solomon is widely recognized as one of the leaders in the field of atmospheric science. Since receiving her PhD degree in chemistry from the University of California at Berkeley in l98l, she has been employed by the National Oceanic and Atmospheric Administration as a research scientist. Her scientific papers have provided not only key measurements but also theoretical understanding regarding ozone destruction, especially the role of surface chemistry. In l986 and l987, she served as the Head Project Scientist of the National Ozone Expedition at McMurdo Station, Antarctica and made some of the first measurements there that pointed towards chlorofluorocarbons as the cause of the ozone hole. In l994, an Antarctic glacier was named in her honor in recognition of that work. In March of 2000, she received the National Medal of Science, the United States' highest scientific honor, for "key insights in explaining the cause of the Antarctic ozone hole." She is the recipient of many other honors and awards, including the highest awards of the American Geophysical Union (the Bowie Medal), the American Meteorological Society (the Rossby Medal), and the Geochemical Society (the Goldschmidt Medal).

More Information
http://cires.colorado.edu/people/solomon/

Susan Solomon