Page:Impact of Climate Change in 2030 Russia (2009).pdf/18

 Projected changes in annual river runoff vary across the country. Winter runoff is projected to increase from 60-90 percent in the Central and Volga Federal Districts, and from 5-40 percent in other Federal Districts. In the Black Earth area and in the south of the Siberia Federal District, springtime river runoff is projected to decrease by 10-20 percent.

Permafrost and Arctic Ice Projections
According to a collaborative report led by Climate Change Risk Management (CCRM), seasonal thaw depths are predicted to increase around 2050 by more than 50 percent in the northernmost permafrost regions, and 30-50 percent elsewhere. By 2100, it is predicted that almost 60 percent of current permafrost regions will thaw and freeze on a seasonal basis. Increased precipitation contributes to the thawing of frozen soils and is projected to lead to a 14 percent increase in freshwater discharge into the Arctic Ocean. Modelers warn that there are significant uncertainties in model projections of changes to the permafrost.

A coupled climate-permafrost model was used by Anisimov and Renava (2006) to calculate changes in permafrost extent and thickness for three timeslices. Model results predict a reduction of near-surface permafrost area by 11 percent, 18 percent, and 23 percent by 2030, 2050, and 2080, respectively. Contractions of near-surface permafrost over these same periods are 18 percent, 29 percent, and 41 percent, respectively.

Despite the uncertainties, most modelers agree that seasonal thaw depths will increase by more than 50 percent in the northern Russia, including much of Siberia and the Far East; and by 30 percent to 50 percent in most other permafrost regions. Figure 3 shows the projected changes in active-layer permafrost thickness in northern Eurasia by 2050. Increased methane emissions from the melting permafrost will be a significant feedback on radiative forcing and climate change. Projected changes in the permafrost to the year 2050 are shown in Figure 3.

Most models project that summer ice will decline much more rapidly than winter ice. Arctic sea ice is projected to decrease more rapidly than other sea ice. Some scientists suggest that the Arctic Ocean could be ice free in summer in the next 10-20 years.