Prior to my PhD I earned my Master's in geosciences from the Pennsylvania State University working with Richard Alley, Michael Mann, and Todd Sowers. I collected ice for the Antarctic WAIS Divide ice core and analyzed that ice for changes in methane over the last 2,000 years. Methane is an important greenhouse gas (it is 20 times more effective at trapping heat than carbon dioxide) and has many significant sources, both natural (wetlands, clathrates, hydrocarbon seeps, wildfires, etc.) and anthropogenic (rice farming, cattle and other ruminants, combustion of hydrocarbons/wood/grasses, oil drilling, etc.). Different sources of methane (i.e. fires vs. farming) have different isotopic signatures. The bulk isotopic composition of methane in today's atmosphere is determined by the relative contributions of each one of its component sources (each with its own unique isotopic composition). Using the WAIS divide ice core as a means to sample the Earth's atmosphere over the last 2000 years I was able to track how the global atmosphere's methane isotopic composition (both carbon and hydrogen) changed with time. I then employed a simple box model run repeatedly with different source configurations to determine the most likely explanation for the temporal changes in atmospheric methane isotopes observed in the ice core. The most significant perturbation in methane isotopes over the last 2000 years has been caused mainly by changes in fire. This conclusion has been reinforced by later charcoal studies. This work was supported by the NSF Graduate Research Fellowship Program and is published here.