Overview
- GEOMAR-led simulations indicate that centuries after emissions peak and turn net‑negative, stored heat from the deep Southern Ocean could resurface and drive more than a century of renewed global warming.
- The modeled pathway assumes emissions peak within about 70 years with atmospheric CO2 doubled, followed by rapid cuts and several hundred years of net‑negative emissions before an abrupt heat release.
- Scientists attribute the projected warming to heat accumulated under earlier global warming that later reaches the surface via deep convection, partially decoupling future temperature trends from immediate emissions.
- AWI analysis of measurements from 1972 to 2021 finds surface freshening since the 1990s has strengthened stratification and temporarily kept CO2‑rich deep waters isolated, preserving the region’s carbon uptake.
- AWI notes the upper boundary of deep water has risen by roughly 40 meters and calls for more winter observations through efforts such as Antarctica InSync to assess whether mixing and CO2 leakage are already increasing.