Permafrost soils contain vast amounts of ancient, frozen soil organic matter. As climate warms, this carbon pool may become available to soil microbes that can transform it into greenhouse gases (CO2 and CH4). How quickly and how much this “permafrost carbon feedback” may amplify climate change is a major uncertainty in projections of future climate.
To help answer this question, PhD student Shawn Pedron built a new greenhouse gas sampler that allows him to collect emissions of carbon dioxide (CO2) from permafrost soils. At UCI, he measures its radiocarbon content, which allows him to understand what proportion of the emissions originates from microbes vs. plants and how much permafrost carbon the microbes are consuming. A major advantage is that this new device collects samples year-round, so that we can better understand the actions of soil microbes during the long, dark Arctic winter.