The dependence found by scientists can be taken into account in warming forecasts
Climate experts from the Russian Federation and the United States found that the global warming rate in the coming decades will strongly depend on the level of species diversity of Arctic microbes involved in organic decomposition in thawed permafrost. The higher this diversity is, the slower the climate will change, the Russian Science Foundation's press service said.
We have managed to prove that the moment of a sharp soar in temperature at the Earth's surface depends on microbial diversity, which is determined by humidity, nutrient contents, and the soil's acidity and warming, the press service quoted Elena Savenkova, senior researcher at the Centre for Scientific Research and Development (Veliky Novgorod, Russia), as saying.
She said that the microbial diversity cannot be influenced, but the dependence found should be taken into account in warming forecasts.
The joint study was conducted by researchers from five institutions: Centre for Scientific Research and Development (Veliky Novgorod, Russia), St. Petersburg State University of Industrial Technologies and Design and the Institute for Problems in Mechanical Engineering of the Russian Academy of Sciences (St. Petersburg) with colleagues from the University of California, and Howard University (the U.S.).
The experts made calculations using an expanded version of the Earth's atmosphere classical model, which British-American atmospheric physicist Richard Goody developed back in the middle of the last century. In that model, the atmosphere is represented as a set of cells where the air circulates between the surface, where it heats up, and the upper layers of the air, where it gives off the absorbed heat.
The Russian and American scientists wanted to learn how this cycle will be affected by the melting permafrost process and the associated release of large amounts of methane as the organic matter trapped in it is decomposed. Guided by this idea, the scientists supplemented Goody's model so that it took into account the processes associated with microbes' activities in the near-surface layers of thawed permafrost, where they feed on organic matter and emit methane.
By using this upgraded version of the model, the scientists managed to discover a previously unknown pattern: with a low level of species diversity and similar optimal living conditions, bacteria in the former permafrost are likely to begin decomposing organics very quickly, thus causing a sharp release of large amounts of methane into the atmosphere. In case of a high level of diversity, such surges actually do not occur, which is due to differences in the optimal conditions of microbial activity.