Global peatland dynamics since the Last Glacial Maximum

TLDR

The study synthesizes global peatland ages, area changes, and carbon pool dynamics since the Last Glacial Maximum, producing a new peatland map and total carbon pool estimates. The analysis reveals region‑specific controls on peatland expansion and carbon accumulation, with northern peatlands accumulating ~547 GtC peaking in the early Holocene, tropical peatlands ~50 GtC peaking 8000–4000 years ago, and southern peatlands ~15 GtC peaking during the Antarctic Thermal Maximum and mid‑Holocene, highlighting diverse drivers that significantly influence the global carbon cycle and methane budgets.

Abstract

Here we present a new data synthesis of global peatland ages, area changes, and carbon (C) pool changes since the Last Glacial Maximum, along with a new peatland map and total C pool estimates. The data show different controls of peatland expansion and C accumulation in different regions. We estimate that northern peatlands have accumulated 547 (473–621) GtC, showing maximum accumulation in the early Holocene in response to high summer insolation and strong summer – winter climate seasonality. Tropical peatlands have accumulated 50 (44–55) GtC, with rapid rates about 8000–4000 years ago affected by a high and more stable sea level, a strong summer monsoon, and before the intensification of El Niño. Southern peatlands, mostly in Patagonia, South America, have accumulated 15 (13–18) GtC, with rapid accumulation during the Antarctic Thermal Maximum in the late glacial, and during the mid‐Holocene thermal maximum. This is the first comparison of peatland dynamics among these global regions. Our analysis shows that a diversity of drivers at different times have significantly impacted the global C cycle, through the contribution of peatlands to atmospheric CH 4 budgets and the history of peatland CO 2 exchange with the atmosphere.