Environmental Impacts from Projected Permafrost Thaw in Alaska: Defining Knowledge Gaps, Data Needs, and Research Priorities.

Thawing permafrost will significantly impact regulatory activities in Alaska that are conducted by the U.S. Environmental Protection Agency (EPA) to protect human health and the environment. Many of those activities are in vulnerable rural lands predominantly occupied by Alaska Natives. Temperatures in Alaska-the largest and northernmost of the 50 states-are increasing disproportionately relative to the global average and at a markedly higher rate than in any other state in the Nation. Most land and surface waters in Alaska are underlaid by permafrost (or perennially frozen ground), which stabilizes infrastructure, serves community needs, and shapes ecosystems with unique environmental characteristics. The Fourth National Climate Assessment estimated that 16-24% of near-surface Alaskan permafrost could disappear by the end of this century. Permafrost thaw not only compromises critical infrastructure used in daily life (e.g., buildings, roads, and pipelines), but also alters movement of hazardous substances within the surrounding environment. Changes to permafrost characteristics and extent may release contaminants through multiple mechanisms which can pollute air, soil, and water, with unintended consequences to subsistence activities and the livelihood of local communities. This paper summarizes information gathered from semi-formal interviews conducted with EPA regulatory staff during late 2022 to glean the breadth of activities that would be affected by permafrost thaw, tabulate available data sources, and identify data and knowledge gaps. This information can be used to influence monitoring activities and future research that can inform EPA regulatory activities affected by permafrost thaw in Alaska.