Impacts of Arctic Permafrost Change on Ecosystems and People: Abrupt Thaw Synthesis & Projections

In partnership with the Permafrost Carbon Network, this workshop will increase collaboration across research disciplines and geographies that have not had other venues to connect on this issue, to evaluate current gaps in our capacity to anticipate the impacts of rapid permafrost change on ecosystem carbon emissions and implications for people. A scaffolded four-day program will include technical presentations, discussions, working groups, and a public lecture.

Four key goals of the workshop are to lay the foundation to:
• Assemble a cross-cutting working group of experts across a range of disciplinary expertise on the topic of abrupt permafrost thaw as it interacts with climate, wildfire, and underlying landscape factors.
• Produce a quantitative synthesis of abrupt permafrost thaw rates and distribution
• Produce regional and circumpolar scenarios that project abrupt permafrost thaw disturbance as triggered by changes in climate and wildfire, with the potential to overlay these with current and future human infrastructure and ecosystem carbon storage.
• Communicate these products both as peer-reviewed publications and in formats designed to reach a range of user-communities

Scientific and Societal Need

Permafrost (perennially-frozen) ground is widespread in the Arctic and provides the structural underpinning for human infrastructure and ecosystems in the region. Permafrost is defined by temperature, but ice and organic matter are other key components of frozen ground that shape the response of permafrost to rapidly changing Arctic conditions, and the cascading impacts on people. Locally, thaw can be directly disruptive to human infrastructure and ecosystem services on permafrost ground. Globally, permafrost thaw alters the carbon cycle and climate, which has far-reaching impacts for people everywhere, not just in the Arctic. Gradual top-down permafrost thaw in response to environmental changes is the primary mechanism encoded into model predictions of changing permafrost landscapes and occurs on the (vertical) scale of centimeters per year. Abrupt permafrost thaw describes the interaction between changing environmental conditions (climate, disturbance/fire), the melting of ground ice along with ground subsidence, and related changes in erosion and mobilization of soil. This process does not occur everywhere. It depends on the ground ice content that can be less than 20% and up to 80% of permafrost ground by volume, and the geomorphological aspects of the landscape undergoing change. But, as the name implies, where it does occur it is rapid and can be catastrophic, thawing through meters of frozen ground in a single season, disrupting ecosystems and human infrastructure at the surface. As a result of the complexities of interacting factors, abrupt permafrost thaw has been studied extensively at the site scale, but it has defied incorporation into large-scale models that would allow for regional projections of landscape response.

Products and Impact

The four goals together are beyond the scope of completion during the workshop itself, but the workshop will lay the groundwork for immediate products and follow-on research projects that could arise. The first goal of assembling the cross-cutting research team will be achieved in the workshop planning and implementation. This will comprise workshop attendees, as well as a broader circle of interested contributors even if they cannot attend. The second and third goals are the primary aim of the workshop. Advance planning in combination with discussions at the workshop will be used to scope out the initial products that are possible as near-term workshop outputs. We will also define mid-term outputs that could include additional peer-reviewed publications and future directions that could potentially shape research proposals outside the scope of the workshop. Finally, the workshop will aim to define user-audiences and communication platforms for broader audiences for this information. A workshop goal will be to enable at least one broader communication item.