Permafrost Peatlands: Stability, Resilience or Collapse under Overshoot Warming? (PRISE)

Thawing permafrost in peatlands is projected to reverse the northern terrestrial carbon sink to a source in coming decades.

Still, evidence from different observational studies and models disagree on when and where sink-to-source transitions of permafrost ecosystems willoccur. The permafrost thaw, once triggered, will likely continue to emit greenhouse gases for centuries.

This raises particular concernthat overshoot warming trajectories, where global warming exceeds target temperature goals, may trigger responses that are nonresilient,and making it difficult to reverse overshoot warming.

PRISE aims at developing the capacity to assess the dynamics and climate feedbacks from northern permafrost landscapes underdifferent global warming scenarios.

This includes assessment of poorly understood and complex emission trajectories anddetermination of where permafrost loss that occurs under warming is resilient (soils refreeze) and where it is irreversible (ecosystemshifts).To achieve this aim, PRISE includes objectives:O1: Generate pan-Arctic maps of permafrost peatland landscapes, including peat depth and ground ice estimates.O2: Include permafrost peatland landscape types in a state-of-the-art ecosystem model including abrupt thaw and potential permafrost resilience.O3: Use new modelling capabilities to assess permafrost peatlands dynamics under global warming and assess how permafrost thaw decreases human allowable emission budgets.