Journal of Geophysical Research: Earth Surface, 20 July 2023
Rising air and water temperatures have increased riverbank erosion in permafrost regions, threatening communities and infrastructure built along rivers across the Arctic. This study measured the heat transferred from flowing water into the frozen soil and sediments of riverbanks. Researchers found that erosion rates directly increase with water temperature, and that riverbanks with greater ice content are more resilient than those with less ice. Notably, this study also observed permafrost erosion rates three times faster than expected when there were no shrubs or smaller plants along the riverbanks to protect them from the water currents. The sensitivity of permafrost to rising temperatures poses a wide range of devastating hazards. Many Arctic communities are located on riverbanks, which provide access for subsistence fishing but pose a major risk to buildings, roads, and power lines as the river erodes into their floodplains. Increasing permafrost thaw in the Arctic provides a clear message that the most effective way to limit such regional and global consequences of cryosphere loss is to uphold the 1.5°C Paris limit through urgent emissions reductions.