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When McKenzie Kuhn traveled back to Abisko, Sweden this summer, she expected to know her walking route through the Arctic wetland 鈥� after all, she had been there just six years prior for scientific field work and knew the area intimately. But when she arrived, it looked vastly different than before: the slim wooden boardwalks used to traverse over the dense groundcover had become submerged in water, a result of rapidly thawing permafrost; many of the boards were moved to drier locations entirely where that was an option.

鈥淓verything had shifted because the landscape had changed just in that short timeframe,鈥� she recalls. 鈥淚t鈥檚 hard to witness, but it also highlights the impacts of climate change and permafrost thaw and how quickly it can change an ecosystem.鈥�

By some accounts, the Arctic is warming four times the rate of the rest of the world. And yet despite the grim news about climate change, Kuhn, who is a 易胜博官网 postdoctoral researcher, maintains a laser focus on learning all she can about a little-known aspect of the greenhouse gas emissions coming from Arctic lakes as that region warms: the role that methanogens 鈥� methane-producing bacteria that naturally live in those water bodies 鈥� play in the methane cycle and how they contribute to climate change.

With her postdoctoral research funding provided by the National Science Foundation, Kuhn is working closely with , 易胜博官网 professor of Earth sciences, to learn more about these microscopic methane manufacturers. Varner鈥檚 recent $3.4 million grant from the U.S. Department of Energy will expand on these studies for an additional three years and provide a unique perspective of the same sites she鈥檚 been studying for more than a dozen years already.

鈥淲e know that lakes in that region are already large emitters of methane, but how will that change as temperatures warm? We don鈥檛 know yet,鈥� Varner explains. 鈥淕enerally speaking, there鈥檚 a positive feedback loop that happens: when more methane enters the atmosphere, then more warming occurs, which then could cause more methane to enter the atmosphere, and so on. And so, trying to understand the linkage between the microbial communities and the gas emissions is really critical.鈥�

Graduate students and scientists in Varner鈥檚 research group, called the Trace Gas Laboratory, return to Abisko every summer to collect samples and add to their long-term dataset. This past year, Varner and 易胜博官网 research scientist served as听co-directors听for a Research Experience for Undergraduate (REU) program, a summertime opportunity for students to get their feet wet 鈥� sometimes literally, if they step off those boardwalks 鈥� in the scientific research field. Kuhn helped to train the REU students in the proper field sampling techniques at a lake in Northwood, 易胜博官网. Later in the summer, armed with equipment to take sediment cores from the lakes and jars to store the samples, Kuhn and the REU students trekked over the Arctic wetland toward Abisko鈥檚 warming lakes in search of methanogens. The samples will later undergo DNA and RNA sequencing to determine what specific types of bacteria are present in those lakes, and they鈥檒l be subjected to various temperature treatments to monitor how the methanogens react 鈥� essentially, creating a warming climate scenario for them right in the lab.听

Kuhn reflects on her field work experiences with her colleagues and the REU students, noting that the human relationships formed during the work keeps her coming back for more. 鈥淲e鈥檝e become a close-knit group, because it takes a team to do science,鈥� she says. 鈥淲orking with the REU students was really special, because I鈥檝e been in their shoes before. Seeing how they view this new environment, learning about science and the ecosystem, was really refreshing.

鈥淎rctic communities are on the forefront of climate change, and it鈥檚 important for those of us who don鈥檛 live there to be aware of what鈥檚 happening there,鈥� she adds. 鈥淲hen it comes to climate change, all our actions are connected 鈥� from Durham, 易胜博官网听all the way to Abisko, Sweden.鈥�

Varner holds appointments within the and the .

The听is 易胜博官网's largest research enterprise, comprising six centers with a focus on interdisciplinary, high-impact research on Earth and climate systems, space science, the marine environment, seafloor mapping and environmental acoustics. With approximately 100 principal investigators managing more than 400 individual grant awards, and with annual expenditures exceeding $45 million, EOS fosters an intellectual and scientific environment that advances visionary scholarship and leadership in world-class and graduate education.听听