For the last hundred years the annual average air temperature on the Earth has increased by 0,6 ̊С and in Russia- by 0,9. In the opinion of the international scientific society, the temperature increase will continue. The scientists of the Krasnoyarsk Science Center SB RAS told us how the global warming can influence the nature and conditions of life in Siberia.

The problem of global climate change has long been a topic of discussions not only in scientific journals. One of the most striking recent public initiatives is the activity of a Swedish school student Greta Thunberg. To attract the attention of the authorities to the climate agenda, in August, 2018 she started a solitary school strike near the Swedish Parliament. Greta wants the politicians to follow «the Paris agreement», which imposes countries to take measures decreasing CO₂ emissions. At present the agreement is not followed in most countries which signed it. Tens of thousands of school children in the whole world took up the initiative of the girl from Sweden. On Fridays, instead of the lessons they go to the streets with similar demands. Recently, Greta has been nominated for the Nobel Peace Prize.

The ideology of the movement«Fridays for future» is based on a simple idea. «What is the purpose of studying for the future if the future might not exist? What is the purpose of spending so many efforts to get education if our governments do not listen to educated people?». Such loud emotional words require scientific validation. Global warming in different places of the world is assumed to manifest itself differently. We decided to understand the consequences of climate change for a particular region and asked the scientists of the V.N. Sukachev Institute of Forest SB RAS about their opinion concerning global warming and the future of Siberia.

Will it be warmer and will there be more food?

«Climate change is one of the global problems, says a climatologist, Doctor of Biological Sciences Nadezhda Chebakova. Under the influence of natural processes the climate on the Earth has always been changing. Now, the amount of CO₂ and of the green house gases is increasing due to the human activity. In the last 50 years their concentration has grown by 25—30 %. Greenhouse gases let shortwave radiation from the Sun penetrate to the Earth, but do not permit long-wave radiation from the heated Earth to leave the atmosphere. So, the temperature on the planet is increasing.

The consequences of the climate change in Siberia can, in general, be called favorable.The climate is assumed to become warmer, thus, it will be better for plants and for people. Since the treeline will shift to the north, to higher latitudes, open areas will appear in the south of Siberia, and they can be used in agriculture. The yield of grain crops and potatoes will increase twice. In Siberia it will be possible to plant crops which were not able to survive here earlier.However, one must remember that forest soils are not always suitable for agriculture. Thus, even if the climate is more favorable for agriculture, its development will be hindered by the absence of suitable lands, and, for arid regions in the south, by the amount of available moisture.

Due to climate warming the forest areas will decrease, on the southern treeline there will not be enough moisture for coniferous trees. An opportunity will appear for broad-leaved forests to establish themselves, for example, linden forests, which were widely spread in the south of Siberia in the middle of holocene, six thousand years ago.In the case of an unfavorable scenario, taiga will be replaced by forest steppe and steppes, fragments of desserts will appear on the border of Tuva and Mongolia. This forecast is made on the basis of climate models until 2100 года which have already been tested. However, to make such long-range forecasts is an ungrateful task».

Not only people love warmth but also insects enjoy it.

«The climate warming will contribute into the increasing areas and mass propagation of insect-pests harmful for forest and agriculture, — says Candidate of Biological Sciences Natalya Kirichenko. The increasing temperature and decreasing humidity are favorable factors for the development of many species of insects. Thus, the outbreaks of Siberian silk moth, a threat for coniferous forests have already been indicated on the boundary of its habitat in the north of Siberia and this abundance was not observed earlier. Siberian silkmoth is able to damage various species of coniferous plants and this ability increases its chances for occupying new areas.

Climate warming can contribute into the penetration of insect-pests from other regions to Siberia. For example, 20 years ago no one would imagine that such a well-known potato-pest as Colorado beetle could appear in our region and get adapted. However, today this species is not only recorded but it also greatly damages potato plantations in several parts of the Krasnoyarsk Region.

Some insect species are capable of developing in a wide temperature range and feed on various species of plants. Such species have great potential for propagation. The consequences of the spreading can be unpredictable. An insect which was rather harmless in its home region, can be a source of great troubles in another place».

Climate fireman or arsonist?

«More than 70 % of the forests which burn in Russia are in Siberia, says a Candidate of Technical Sciences Evgeny Ponomarev. For about 25 years, Krasnoyarsk scientists have been carrying out real time monitoring of forest fires and their risks in Siberia.The accumulated information allows one to make a conclusion that with years the number of fires and their impact areas are increasing. The highest level of fires observed in the north, hundreds of thousands hectares of forest burn there every year.

According to the estimates of climatologists, increasing temperatures during the growth season have been observed as well as changes in the amount of precipitation. In some regions a great number of fires per year is indicated which is due to high heat and insufficient amount of precipitation. If the climate changes the situation concerning fires can aggravate, forests will burn more often and the area of forest fires will increase.

Forest fires are always accompanied by emissions of gases and soot. According to the existing climate models, even with a slight increase in temperature, we can expect a doubling of emissions from fires in the forests of Siberia by the end of the century. This will further increase the carbon content in the atmosphere and enhance the greenhouse effect. Smoke plume from a fire is also a direct threat to humans. For example, due to the smoke, airports are being closed, the state of air is deteriorating, and therefore, the quality of life is decreasing. A major fire is a risk for populated areas.

If the heat and moisture conditions change, the level of natural fire hazard also changes. This is especially pronounced in areas with frozen soils and regions of Siberia with wetlands, having a large amount of combustible material and peat. With a high level of groundwater, the probability of fire for such areas is small, but it increases when this level drops. Peat fire is dangerous as it spreads underground, which makes it difficult to trace and prevent. Now, mainly forest and steppe fires are recordedin Siberia. But there are large areas of peatlands and swamps in Western Siberia, in the north, and in the permafrost zone. In the case of severe climate change, we should take care of their future state

Permafrost is not so eternal

“When the temperature rises, the soil warms up, the permafrost layer decreases, and the active soil thawing in summer increases the soil layer,” explains Anatoly Prokushkin, Candidate of Biological Sciences. - Permafrost can be different - insular, intermittent, continuous one. It is intermittent permafrost, with non-frozen areas observed among frozen soil, which is now exposed to considerable effects and is rapidly deteriorating. In the area of continuous permafrost, the depth of the frozen strata can reach 200–300 meters and even more. The average annual air temperature in such zones is well below zero. Even with a two-degree temperature increase, these regions will remain in the region of negative temperatures. So, we should not expect that all the permafrost will melt in the next hundred years. What will increase is a layer of soil thawing in summer. Soil in this case loses its properties. It is dangerous for roads or buildings located in these areas.

Melting permafrost is frightening due to the release of organic carbon that has accumulated there for hundreds of thousands of years. Thawed organic matter becomes available to microbes that will feed on it. In this case, CO₂ and methane, greenhouse gases, are intensively released. Global warming is believed to be due to the release of these gases. If melting permafrostwill continue contributing to the release of these gases, then the warming will only be intensified. Up to 60–70% of the total organic matter of the world's soil is concentrated in northern ecosystems. But the permafrost can be protected by nature itself. If the forestsmove northward, they should isolate it, then the degradation rate can become much lower. However, the speed of the shift of the forest treeline is slower than the speed of the observed climate changes. ”

It turns out that Krasnoyarsk scientists dispel the common myth about the possible benefits of warming for our latitudes. In the future, climate change can play a cruel joke with us – give us the warmth, but ultimately lead to negative consequences in the form of fires, droughts, insect pests and changes in the usual way of life associated with the predictability of weather and environmental conditions.