Biology

Dr. Jason Polk collects geochemical data and water samples from a river flowing from beneath a glacier in Iceland.

Dr. Jason Polk, Associate Professor of Geography and Geology and Director of the WKU Center for Human GeoEnvironmental Studies (CHNGES), is joining a team of international scientists to serve as an Expert Reviewer for the Intergovernmental Panel on Climate Change (IPCC) AR6: The Physical Basis, the next global report on the current status of climate change science.

Dr. Polk will contribute to Chapter 5 focused on Global Carbon and other Biogeochemical Cycles and Feedbacks.

The Intergovernmental Panel on Climate Change is preparing this main assessment report, AR6, for Working Group I of the Physical Science Basis for release to scientists and policymakers. The IPCC was established in 1988 as an international body representing over 190 countries under the auspices of the United Nations to serve as a leading authority on climate change issues. Since 1990, the IPCC has produced assessments of global climate data that serve to drive policy and resilience decisions for countries all over the world aiming to mitigate the effects of a changing climate.

“It is both an honor and a career highlight to be able to contribute my expertise to reviewing the latest IPCC report,” Dr. Polk said. “In working with my students, I always encourage them to conduct their research with the highest level of objectivity and data integrity, because one never knows when his or her results might be used for something as impactful and important as a report like this. I have an even deeper appreciation for the rigorous writing and review process that the IPCC scientific reports undergo through my experience in this process and am grateful for the positive experience in working with fellow scientists to ensure we are using the best available scientific data when making decisions to address issues related to a changing climate.”

Dr. Polk is participating as a member of the Past Global Changes (PAGES) Early Career Network (ECN), which is part of a consortium of organizations that include the Permafrost Young Research Network (PYRN), Young Earth System Scientists (YESS), Young Professionals Network of the World Commission on Protected Areas (WCPA), and Association of Polar Early Career Scientists (APECS-IPCC). These organizations represent some of the world’s most prominent scholars studying both past and present global change toward enhancing our understanding and response to pressing issues related to the world’s climate and ecosystems. His review will include providing an objective assessment of the science and to ensure that all scientific views are represented in a balanced and accurate manner.

Dr. Polk is providing expertise because of his research expertise on reconstructing past climate conditions from environmental records preserved in caves and sediments and, more recently, his work at WKU with students that involves studying carbon fluctuations from large reservoirs previously understudied in extreme environments, including rapidly melting glaciers in Iceland and groundwater systems at Mammoth Cave National Park, home to the longest cave in the world.

Collectively, these types of environments present interesting and complex biogeochemical feedback cycles affecting the rate of carbon release or sequestration in various natural processes impacted under, or contributing to, a changing climate.

In Iceland, this includes the increased rate in glacier meltwater feeding rivers throughout the country, which is impacted by increasing global temperatures and interactions between the meltwater and local bedrock. Quantifying these measurements can be difficult, due to the addition of carbon from gases trapped in the glacier and the changing atmospheric concentration. Just as challenging is the ability to determine carbon flux measurements in cave systems that function as part of the carbon cycle through the dissolving of carbonate (limestone) rock by the groundwater in the karst landscapes in which they are formed.

At Mammoth Cave, Kentucky, this process is even more complex, due to the size of the cave system in being the longest in the world, as well as the interactions between the Green River and the springs flowing from the cave into it, which can reverse direction when the river is flooding and change the input and cycling of carbon within the system on relatively short timescales. Being able to quantify these relationships is only possible through extensive, detailed studies of the water’s geochemistry, atmospheric conditions, and the collection of high-resolution data that allow for calculating the volumes of carbon being released or stored daily, seasonally, and annually. Feedbacks from the climate system affect these natural systems and need to be considered as well; therefore, working with collaborators from around the world, Dr. Polk and his students engage in applied research that contributes to the scientific basis from which reports like the IPCC AR6 are developed.

The IPCC AR6 report is scheduled for release in April 2021 and will continue to be reviewed and revised to ensure the highest quality summary of the status of climate change data and its potential implications for use in future investigations of the climate system and policies governing the world’s interaction with it in the future.

Dr. Fred Siewers, Chair of the Department of Geography and Geology, said: “The research being conducted at WKU in the Geosciences and through CHNGES provides applied student engagement opportunities that contribute to the datasets and future policy actions that help inform perceptions and behaviors affecting the entire world on topics like climate change. We welcome all students interested in these types of experiences.”

As part of WKU’s Applied Research and Technology Program (ARTP), which focuses on applied student learning experiences, CHNGES is actively seeking graduate students interested in studying global environmental change through an applied lens.

For information, contact Dr. Jason Polk at jason.polk@wku.edu or 270-745-5015.