Permafrost tipping point triggered by warming-driven loss of old carbon
8 hours ago
- #Tibetan Plateau
- #permafrost
- #carbon feedback
- Low-to-moderate warming (<2°C) leads to respiratory carbon loss increases exceeding photosynthetic gains by 1–16 fold, turning ecosystems into a carbon source.
- Extreme warming (2–4°C) causes a surge in deep carbon loss to 59% of ecosystem respiration, while photosynthesis declines, indicating a tipping point.
- At projected end-of-century warming (2.69°C), Tibetan permafrost could release 24–47 g CO2 m−2 yr−1 of old carbon, establishing thresholds for carbon vulnerability.