Russian scientists analyzed greenhouse gas emissions in different landscapes of Siberia and came to the conclusion that permafrost is more stable than previously thought and does not significantly contribute to climate change. The results of the work were published in the journal Environmental Research.
Today, climate change is considered as one of the main threats to all life on Earth and humanity in particular. At the same time, Siberia has a massive permafrost layer with a high content of organic carbon. Due to its melting, huge volumes of carbon dioxide can enter the atmosphere. Having a greenhouse effect, it can increase the temperature, while accelerating the release of new portions of gases from the same zone. Thus, the process goes in a circle and, according to some scientists, can lead to a serious acceleration of global warming.
The new work of scientists from the Krasnoyarsk Scientific Center of the SB RAS shows the comparative intensity of greenhouse gas emissions in different regions of Siberia, and the influence of permafrost on this process. Researchers have determined that emissions of carbon dioxide and methane differ significantly between natural zones and regions of Siberia. This is due to the warming up of the soil, biological factors, as well as the peculiarities of the landscapes of the territories and the gases emitted.
Researchers analyzed three thousand observations and came to the conclusion that in some parts of Siberia, the non-permafrost zone emits more greenhouse gases than areas with permafrost. This is typical, for example, for Western Siberia. In other areas, however, the opposite is true. In Central Siberia, the volume of greenhouse gases in the permafrost zone exceeds their emissions in the non-permafrost zone.
Scientists have noticed significant changes in greenhouse gas fluxes over the past thirty years. In the non-permafrost soils of Western Siberia, the emission of carbon dioxide increases, and in the middle part, its emissions decrease. The permafrost soils of Eastern Siberia began to release more methane, while the flows of this gas in the non-permafrost zone of Western Siberia began to decrease over time.
One of the reasons for this, according to scientists, is the reaction of soil microorganisms and plants to heating the soil surface. With an increase in temperature, the activity of microbes and the respiration rate of plant roots increase, which leads to an increased emission of carbon dioxide. The second reason is related to the characteristics of greenhouse gases. Methane is released by anaerobic bacteria. Therefore, wet places usually contain more of this gas, which means more methane is produced there than in dry ones.
In the case of carbon dioxide, the relationship is directly opposite. These factors affect the amount of emissions. For example, in relatively dry ecosystems, more carbon dioxide is emitted, while in places with high humidity, more methane. According to the authors of the work, the climate still affects the rate of emission of gases from permafrost. It may be stable now, but it is still a potential source of a huge amount of greenhouse gases, the release of which into the atmosphere threatens an even greater rise in temperature. Therefore, it is necessary to constantly monitor this process and monitor the state of permafrost and non-permafrost zones.