March 6, Thursday -- Katey Walter, a 2000 master's degree alumna of the аÄÃÅÁùºÏ²ÊÄÚÄ»ÐÅÏ¢ Davis Graduate Group in Ecology, will speak on campus on Thursday, March 6, about an emerging concern in climate-change studies: methane emissions from Arctic lakes. Walter, now assistant professor of limnology, water and environmental research at the University of Alaska, Fairbanks, is one of the first people to calculate the methane bubbling out of melting lakes. "The carbon that the bacteria are eating has been locked up in the permafrost, in the freezer, for tens of thousands of years. And today with climate change, as more of this permafrost is thawing, you're defrosting that meal for the bacteria," she told National Public Radio listeners last year. Walter's talk is set for 4:10 p.m. to 5:15 p.m. in Room 1100 of the Social Sciences and Humanities Building. Members of the public are welcome; the talk is free.