By Diane Kuehn, SUNY-ESF
Dr. Brenda Ekwurzel a Climate Scientist with the Global Environment Program, Union of Concerned Scientists (UCS) based in Washington, DC, spoke at the State University of New York College of Environmental Science and Forestry (SUNY-ESF) on Tuesday, March 6 on “Global Warming: The Science behind the Headlines.” The presentation was co-sponsored by the Women in Science and Engineering (WISE) Initiative of Syracuse University, SUNY-ESF, the ESF Women's Caucus, and the Syracuse University Graduate School. The presentation was part of SUNY-ESF's Women in Scientific and Environmental Professions Speaker Series.
Dr. Ekwurzel began her presentation by discussing climate changes and trends since 1850. Some of the points she mentioned were:
· 7% of the maximum area of frozen ground has decreased since 1900 in the Northern Hemisphere.
· Satellite data collected since 1978 indicate a 20% reduction in the extent of summer sea ice.
· Eleven of the last twelve years have been the hottest on record since 1850.
Dr. Ekwurzel discussed the connection between reduced sea ice and snow coverage and the increased average global temperatures. Specifically, since sea ice and snow work to reflect back into the atmosphere about 90% of the sun’s energy, losing ice actually increases heat absorption by the earth.
Why is the snow and sea ice melting? Given the relative stability of the sun’s energy output and of the amount of other particles in the air (such as those from volcanic ash) over time, most of the change appears to be due to increasing amounts of heat-trapping emissions in our atmosphere. Carbon dioxide, for example, is produced in large quantities by fossil fuel-burning machines and power generation facilities today and, because of its slow absorption by the earth’s oceans (absorption can take anywhere from 50 to 1000 years), accumulates in our atmosphere over time. Methane (average absorption time of 12 years) and nitrous oxide (average absorption time of 114 years) are two of the other heat-trapping gases.
What can we expect in the future in Central New York? Dr. Ekwurzel discussed future changes such as the annual average temperature rising, shorter winters, and a shorter coverage of ice on nearby lakes. She also stated that there will likely be more intense precipitation, both in the winter and during other seasons as well, when storms do occur. Elsewhere in the country, subtropical areas will likely continue to dry out, coastal areas may experience flooding, and urban areas (because of the extensive amount of pavement and buildings) will have amplified summertime temperatures.
What options does our society have for the future? The first option that Dr. Ekwurzel raised is to decrease the amount of longer-lived gases (e.g., carbon dioxide) released into the atmosphere to prevent the buildup of these gases over time. Our society may also need to adapt to climate changes over time by altering the design of our homes or the location of our residences (e.g., away from coastal areas). Finally, Dr. Ekwurzel emphasized the need for new options for the future.
Dr. Brenda Ekwurzel works on the national climate program for the Union of Concerned Scientists (UCS). She is leading UCS's climate science education work aimed at strengthening support for strong federal climate legislation and sound U.S. climate policies. Prior to joining UCS, Dr. Ekwurzel was on the faculty of the University of Arizona Department of Hydrology and Water Resources with a joint appointment in the Geosciences Department. Her specialty is isotope geochemistry, a tool she has used to study climate variability in places as disparate as the Arctic Ocean and the desert Southwest. She has published on topics that include climate variability and fire, isotopic dating of groundwater, Arctic Ocean tracer oceanography, paleohydrology, and coastal sediment erosion. She has also worked as a hydrologist with the Connecticut Department of Environmental Protection, working with communities to protect groundwater sources. Dr. Ekwurzel completed her doctorate work at Lamont-Doherty Earth Observatory of Columbia University and post-doctoral research at Lawrence Livermore National Laboratory in California.