A new study published in the Proceedings of the National Academy of Sciences reveals that the combined effects of sea level rise, permafrost thaw subsidence, and coastal erosion could lead to significant land loss along Arctic coastlines. Conducted by researchers from the Woods Hole Oceanographic Institution (WHOI) and other organizations, the study highlights the urgency of addressing these overlapping hazards.
The focus of the research is Alaska's Arctic Coastal Plain (ACP), a low-elevation area covering over 60,000 square kilometers. This region is experiencing some of the fastest rates of sea level rise and coastal erosion in the Arctic, compounded by land subsidence from thawing permafrost.
By the year 2100, projections indicate that the North Slope shoreline may retreat to positions not seen in over 100,000 years. The researchers emphasize that the rapid transformation of these coastlines necessitates immediate action to protect vulnerable communities and infrastructure.
While coastal erosion has been well-documented, this study uniquely incorporates the effects of permafrost thaw and sea level rise. Data from high-resolution topography and satellite observations suggest that land loss could surpass erosion-related losses by as much as eight times under medium- and high-emission scenarios.
Dr. Pier Paul Overduin, a researcher involved in the study, noted that the land surface in ice-rich permafrost areas is subsiding faster than sea levels are rising, indicating that permafrost thaw will significantly influence Arctic coastal changes in the long term.
The implications of Arctic land loss are profound, threatening local infrastructure, cultural heritage, and access routes essential for subsistence. The researchers call for adaptive planning that accounts for the cumulative effects of climate hazards.
Lead author Dr. Roger Creel stressed that while the impacts of permafrost thaw are recognized by residents in northern Alaska, federal agencies may not fully appreciate its role in coastal change. He urged for a broader dialogue on the issue.
Co-author Julia Guimond highlighted that the findings from Alaska's ACP have global relevance for coastal resilience planning, underscoring the need for a comprehensive understanding of climate hazards as communities prepare for rapid changes in the 21st century.