Up to 450 billion tons of soil carbon has accumulated in high latitude ecosystems after the retreat of the last major ice sheets. Recent studies suggest that these ecosystems may no longer be accumulating carbon in soils, and in some cases may be losing stored carbon to the atmosphere. This study will use measurements of radiocarbon isotopes to ask the question: Is old carbon that comprises the bulk of the soil organic matter pool released in response to thawing of permafrost? Field measurements will center on a site in Alaska where permafrost has been observed to warm and melt over the past several decades. This area is unique for addressing questions at the time scales relevant for change in arctic ecosystems. This project has broad significance for changes in the global carbon cycle. Transfer of carbon now stored in waterlogged and frozen soils to the atmosphere could cause a significant positive feedback to climate change due to the large size and potential reactivity of this carbon reservoir. In addition to the measurement program, this project will support an experienced journalist to spend time in the field each year as a consultant to the project. She will interface with scientists and communicate the results of the research by producing stories for various public radio and print outlets. These stories will share the research questions and implications of this project with a broad-based, lay audience.
