Northern Peatlands: Role in the Carbon Cycle and Probable Responses to Climatic Warming

TLDR

Boreal and subarctic peatlands store 455 Pg of carbon, accumulating at ~0.096 Pg yr⁻¹, yet estimates of stocks and fluxes—especially for Soviet peatlands—are uncertain and fire also plays a significant role. The study investigates how water‑table changes influence CO₂ and CH₄ fluxes across peatlands, particularly in warming regions, and evaluates satellite monitoring of open water as an early indicator of climatic impacts. The authors employ Clymo’s 1984 model to estimate current carbon fluxes and propose satellite monitoring of open‑water abundance to detect early warming effects. Long‑term drainage oxidizes ~0.0085 Pg C yr⁻¹ to CO₂, combustion adds ~0.026 Pg C yr⁻¹, and CH₄ emissions release ~0.046 Pg C annually.

Abstract

Boreal and subarctic peatlands comprise a carbon pool of 455 Pg that has accumulated during the postglacial period at an average net rate of 0.096 Pg/yr (1 Pg = 1015 g). Using Clymo's (1984) model, the current rate is estimated at 0.076 Pg/yr. Longterm drainage of these peatlands is estimated to be causing the oxidation to CO2 of a little more than 0.0085 Pg/yr, with conbustion of fuel peat adding °0.026 Pg/yr. Emissions of CH4 are estimated to release ° 0.046 Pg of carbon annually. Uncertainties beset estimates of both stocks and fluxes, particularly with regard to Soviet peatlands. The influence of water table alterations upon fluxes of both CO2 and CH4 is in great need of investigation over a wide range of peatland environments, especially in regions where permafrost melting, thermokarst erosion, and the development of thaw lakes are likely results of climatic warming. The role of fire in the carbon cycle of peatlands also deserves increased attention. Finally, satellite-monitoring of the abundance of open water in the peatlands of the West Siberian Plain and the Hudson/James Bay Lowland is suggested as a likely method of detecting early effects of climatic warming upon boreal and subarctic peatlands.