A sweeping new study reveals that as Arctic permafrost thaws, it is dramatically reshaping rivers and releasing vast amounts of ancient carbon that had been locked away for thousands of years. By analyzing decades of high-resolution data across northern Alaska, scientists found that runoff is increasing, rivers are carrying more dissolved carbon, and the thawing season is stretching further into the fall. This carbon eventually reaches the ocean, where some of it turns into carbon dioxide, intensifying global warming.

One of the most notable findings is how much of the change is tied directly to permafrost thaw. The thaw season now lasts longer than in the past, extending into September and even October.

These changes are likely affecting salinity, nutrient cycles, and food webs in the Beaufort Sea. Researchers are now studying how ice wedge polygons, a common Arctic landscape feature, influence how water and carbon move toward coastal areas.