[24] Based on the INM RAS atmosphere-ocean general circulation model, we have analyzed some results of the reproduction of the observed climate and its changes in he XX century and estimated the climate changes expected for the late XXI century, for three scenarios of the concentrations of greenhouse and other gases. The observed global warming by 0.6-0.7oC in the XX century is most likely caused by enhanced concentrations of greenhouse gases, since a similar warming is obtained in all 5 calculations with observed changes in the concentrations of all gases, but in none of the three calculations where the concentrations of all gases are fixed at the level of 1871.
[25] The results of the INM RAS model indicate that in the late XXI century the value of global warming will be 3.5oC, 2.6oC, and 2.0oC for scenarios A2, A1B, and B1, respectively, which is close to the estimates of global warming averaged over all 20 models involved in the intercomparison project. The strongest warming is expected to be in the Arctic and continents at moderate latitudes. The global warming will lead to a reduction in the area of sea ice, with the most considerable reduction taking place in the late summer in Arctic, when the predicted ice cover in the late XXI century will melt down completely or almost completely. In winter, the reduction of the area of sea-ice cover may be some 20-30% of the current value. According to the INM RAS model results, the rise in the level of the world ocean due to thermal expansion may constitute 13-20 cm by 2100 and 25-45 cm by 2200. Under global warming, it is expected also that the amount of precipitation will grow by 10-30% at moderate and high latitudes and, caused by this, the soil humidity and river runoff will increase. The amount of precipitation may decrease in many subtropical areas, especially, in the Mediterranean and Central America.
[26] The warming on the territory of Russia is expected to be higher than the value averaged over the Earth. For scenario A1B under the global warming value of almost 3.3oC, the winter warming in Russia will be from 4-6oC in the south to 8-10oC in the north. In the coldest months of winter, the warming is expected to be stronger than, and in the warmest months to be weaker than on the average in winter. In summer, the warming in Russia will constitute from 5-6oC in the south to 3-4oC in the north; in this case, in the warmest (coldest) months of summer, the warming is expected to be stronger (weaker) than on the average in summer. On the most part of Russia, the amount of precipitation is expected to grow by a factor of between 1.1 and 1.5, except for the south, where a decrease by 10-20% is expected. An increase in the amount of precipitation in the months of highest humidity is expected in almost all the territory of Russia by a factor between 1.1 and 1.3, except for the south, where this value will not be significantly changed. In the driest months, a reduction in the amount of precipitation is expected for the south by a factor of 1.5-2, and a precipitation increase of the same factor is expected in the most part of the remaining territory. In the south, one expects an extension of the maximum duration of the no-precipitation period by 2-6 days, while in the northern part of Russia, a reduction by 1-3 days is expected. In the most part of the territory of Russia, one also expects a growth in the number of days with precipitation of more than 10 mm by 2-6 days, except for the south, where the number of these days will not be significantly changed.
[27] By the late XXI century in Russia, there will be a noticeable (by 20-50 days) growth in the length of vegetation period and a reduction of frosty days. The growth is expected to be the highest in central regions of the European part of Russia. By the late XXI century, one predicts a considerable reduction in the area of permafrost.
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