Global peatland dynamics since the Last Glacial Maximum

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 CH₄ budgets and the history of peatland CO₂ exchange with the atmosphere.