All news

Microbe diversity in Arctic affects climate change rate — scientists

Elena Savenkova and other experts came to this conclusion when they made calculations using an expanded version of the Earth's atmosphere classical model

TASS, December 7. 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 Center for Scientific Research and Development (Veliky Novgorod), as saying. "We are unable to influence the microbial diversity, but the dependence we have found must be taken into account in warming forecasts."

The expert and other scientists came to this conclusion when they 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 researchers 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.

The existing climate models do not take into account this feature of the Arctic microflora, and thus based on them mid-and long-term temperature forecasts for the Arctic and the whole planet may be overestimated or underestimated by several degrees Celsius at a time. This is why the Russian and American scientists suggest taking into account the influence of bacterial species diversity in work on such assessments.

Unstable permafrost

The rapidly melting permafrost in the Arctic in global warming has become a big problem for many Russian and foreign cities located in the Arctic. The disappearing permafrost destabilizes foundations of buildings and causes infrastructure discrepancies, which in the coming decades, according to Russian and foreign climate experts, may cost the Russian economy more than 422 billion rubles ($4.5 billion).