ESI Director Jay Banner was selected as the 2015 Kappe Lecturer of the American Academy of Environmental Engineers and Scientists. This prestigious lectureship was endowed in 1989 to “share the knowledge of today’s practitioners with tomorrow’s environmental engineers and scientists” and involves a national university speaking tour. Dr. Banner is the first scientist to ever be honored, as all previous speakers were engineers. Per tradition, Banner is offering two talks to be selected from by the host institution at each venue visited on the speaking tour. The two abstracts are below.
More information on the Kappe Lectureship may be found here: http://www.aaees.org/kappelecturer.php.
And check out photos and stories from the road on ESI’s Facebook page: https://www.facebook.com/Environmental-Science-Institute-323466967664835/.
Past, Present, and Future Climate Change Impacts on Water in a Semi-Arid Region: Science and Policy
Texas comprises the eastern portion of the Southwest region, where the convergence of climatological and geopolitical forces has the potential to put extreme stress on water resources. Geologic records indicate that Texas experienced large changes in moisture sources and amounts on millennial time scales in the past, and over the last thousand years, tree-ring records indicate that there were significant periods of drought in Texas. These droughts were of longer duration than the 1950s “drought of record” that is commonly used in planning, and they occurred independently of human-induced global climate change. Although there has been a negligible net temperature increase in Texas over the past century, temperatures have increased more significantly over the past three decades, and the region experienced a record drought in 2011 that is ongoing. Under essentially all climate model projections, Texas is susceptible to significant climate change in the future. Most projections for the 21st century show that with increasing atmospheric greenhouse gas concentrations, there will be an increase in temperatures across Texas and a shift to a more arid average climate. Studies agree that Texas will likely become significantly warmer and drier, yet the magnitude, timing, and regional distribution of these changes are uncertain. With a projected doubling of the state’s population by 2065, science, engineering, and economics are essential elements needed for the state’s planning for the projected changes.
Cave Mineral Deposits as Proxies for Past Climate Change
Cave mineral deposits, or ‘speleothems’, provide a record of past changes in the composition and amounts of cave drip water that feed their growth. In turn, these changes in drip water may be used to infer past changes in climate above caves. Given that caves occur on all continents and that speleothems can grow continuously on time scales of decades to over 100,000 years, there is much interest in their application to reconstructing large and abrupt Pleistocene climate changes and Holocene changes that influenced early civilizations. With modern mass spectrometry, methods for dating and geochemical analysis of speleothem growth layers offer the prospect of high resolution reconstructions. These prospects are balanced by the complexity of non-climatic processes that can affect speleothem compositions, during transmission of water through the vadose zone and in the cave environment. These processes are addressed through examination of modern karst systems, including monitoring of physical and chemical hydrology, cave meteorology, speleothem growth on artificial substrates, and chemical and isotopic equilibrium. Studies from Texas and the tropics portray the information speleothems provide regarding past changes in temperature, rainfall sources and amounts, vadose flow paths, and seasonality.