Modelling past and future peatland carbon dynamics across the pan-Arctic

Area of Science:

• Environmental Science
• Climate Science
• Ecology

Background:

• Northern peatlands are crucial carbon sinks, sequestering vast amounts of carbon since the Holocene.
• Estimating regional carbon accumulation in remote peatlands remains challenging due to their vast extent.

Purpose of the Study:

• To quantify long-term carbon accumulation rates in northern peatlands.
• To assess the impact of historical and future climate change on peatland carbon balance using a dynamic vegetation model.

Main Methods:

• Utilized the LPJ-GUESS dynamic global vegetation model with peatland and permafrost functionality.
• Constrained the model using peat basal age data to create a pan-Arctic peat inception surface.
• Analyzed carbon accumulation changes under two warming scenarios (RCP8.5 and RCP2.6).

Main Results:

• Peatlands remain carbon sinks under both warming scenarios, but sink capacity decreases significantly under high warming (RCP8.5) after 2050.
• Areas initially limited by permafrost show increased carbon accumulation due to warming-induced thaw, higher precipitation, and elevated CO2.
• Peatlands in Europe and between 45-55°N latitude, especially those without permafrost or with reduced precipitation, are projected to lose carbon.

Conclusions:

• Rapid global warming poses a threat to the carbon sink capacity of northern peatlands.
• Future climate change will alter regional carbon balance in peatlands, with varying impacts based on permafrost presence and precipitation changes.