Will increased precipitation reduce methane consumption in a future Arctic?

Our knowledge of the Arctic methane (CH4) budget is strongly influenced by measurements from carbon-rich wetlands, which emit large amounts of CH4. Less attention has been paid to the significant and strongly regulating CH4 consumption.

The flow of CH4 to and from the soil depends on two processes: uptake (drier soils, good oxygen supply) and production (water-saturated, anoxic environments). In previous projects, we have shown increased CH4 uptake in plant communities adapted to a warmer climate.

So far, there is very little knowledge about how the increased precipitation will influence this.With a changing climate, the Arctic plant communities react quickly, increasing height and biomass. This increases evapotranspiration, resulting in drier soil and increased oxygen availability. In addition, the plant communities change, leading to increased drainage and drier surface layers.

However, with rising temperatures, precipitation also increases.

We are now heading towards a rain over snow dominance, which potentially leads to wetter soils, reduced oxygen availability and reduced CH4 consumption.We hypothesize that increased precipitation will counteract the positive temperature response seen in Arctic CH4 consumption.

The response will look different in wetlands, where increased precipitation favours CH4 emissions, as compared to drier environments, where increased precipitation may benefit CH4 consumption. This balance is the key to understand climate feedback from the Arctic.