Researchers create more accurate model for greenhouse gases from peatlands

A press release from Argonne National Laboratory: Scientists at the U.S. Department of Energy’s Argonne National Laboratory have created a new model to more accurately describe the greenhouse gases likely to be released from Arctic peatlands as they warm. Their findings, based on modeling how oxygen filters through soil, suggest that previous models probably underestimated methane emissions and overrepresented carbon dioxide emissions from these regions.

Peatlands, common in the Arctic, are wetlands filled with dead and decaying organic matter. ...Cold temperatures keep the carbon locked in the soil. As the ground warms, however, microbes come to life and begin to decompose all that organic matter, which releases carbon into the atmosphere. Unfortunately, the extreme northern regions of the world are where warming has accelerated the most quickly—and it’s expected to pick up in the future. Scientists are concerned that Arctic warming could spiral quickly into a self-reinforcing cycle that dumps an enormous amount of carbon into the atmosphere.

...Up until now, researchers had been using a simple model that assumed water was the primary divider; soil above the water table would produce microbes that made CO2, and microbes below would produce methane. “But experiments had been showing that there could be significant limits on oxygen availability above the water ta
ble, and this would affect what form of carbon microbes release,” Fan said.

The size and characteristics of soil particles matter. If the oxygen gets trapped in air bubbles and consumed by other microbes or can’t filter down through soil, soil microbes will produce methane even if they’re above the water table. “So we set out to make a model that would take these findings into account,” Fan said.

The team used experimental data from peatland taken near Fairbanks, Alaska and plugged it into their model. The results showed their new model was much more accurate and suggested that more methane is produced and proportionally less CO2—than predicted by older water table-based models. “Revising this calculation will substantially affect current greenhouse gas production models in the Arctic,” Fan said....

Looks like a bulldozer sinking into thawing muskeg in Alaska, shot by Wyoherminator, public domain