Uzbekistan and climate change problem
Climate change consequences for Uzbekistan
The first experience of climate change consequences assessment in Uzbekistan has been taken during the UNDP|GEF project “Uzbekistan – country study on climate change”. The assessment is based on regional climate scenarios with use of different methods (modeling, empiric-statistical researches, and expert estimations).
Expected changes
As the result of warming the border between dry tropical and moderate climate zones will shift towards the north on 150-200km and high climate zones will shift on 150-200km. Durance of the without frost period will grow on 8-15 days. Air active temperature summary for different cultures will grow on 5-10%. Air temperature increasing on 1,5-2,00C in many regions of Uzbekistan will cause change of winter regime to the regime of unsteady “vegetational” winter, which may decrease the fertility of desert grasslands.
In general, carbon dioxide concentration increasing at other propitious conditions positively influences on growth of plants (increasing of photosynthesis speed). At optimal conditions of moisture providence fertility increasing of cotton, cereals and corns and pasture vegetation is possible. But will the conditions be so propitious? Where to find enough water for the irrigation? There are no enough water resources even at present time.
At moisture deficiency and high temperature influence, which is the cause of global warming, crop losses of agricultural plants and pastures may significantly exceed the possible increasing because of the rising of carbon dioxide concentration in the atmosphere.
Decreasing of desert pastures and increasing of amount of days with high temperature will deteriorate cattle grazing conditions on the plain territories, i.e. warming loading increasing, which decreases animals’ productiveness.
How will climate change influence on human health in the Republic?
The answer to this question is to be find. Not only straight influences threw increasing of thermal stress and connected with it illnesses (ischemic heart disease, respiratory, kidney illnesses and illnesses of the nerve system, etc.) are possible. There also can be an indirect influence. For instance, increasing of amount of infection illnesses, connected with natural-center infections’ areal change, rising of infection level because of the deterioration of quality of drinking water and its deficiency in ecologic strained regions. To provide people with food will also be problematical at soil fertility losses and water deficiency. Evaporation rising in warming conditions will increase water losses in the irrigation zones.
What were the results of water resources’ observations? According to most of the climate scenarios our country will have almost the same water resources, as it has at present. But in the case of the realization of extreme scenario significant decreasing of drainage is possible. For example, different models at the doubling of CO2 concentration show, that Amudarya drainage may fall on more than 1/3, and Syrdarya drainage on 1/5.The structure of drainage formation will change because of climate change. Model calculations of snow and glacier reserves in the mountains according to different climate scenarios had shown their general decrease. Decreasing of thaw snow water entering enclose and rain enclose increasing are expected. Time shift of the spring high water will happen for the rivers with snow-rain type of nourishment.
Amudarya today is the ideal river for the irrigated field in seasonal drainage distribution – the peak of the flood is in June. In warming conditions rising of river’s winter drainage level and falling of summer one is expected. Such redistribution will be the cause of mountain glaciers’ melting and rain share increasing. Glaciers of rivers of Aral Sea basin during the period of 1957-1980 lost almost 20% of its ice reserve, and loses had compiled another 14% by the year 2000. Expected drainage level fall in vegetation period is especially negative for the irrigational agriculture and separate ecosystems (littoral, delta ecosystems, etc.). Together with rainfall level increasing general growth of rainfall intensity is expected and it will cause rain floods, increasing of soil erosion and drainage turbidity. All fields of mountain hills may become the place of mud flow activity intensive development.
The water in our arid region has a high value and it will only increase in the future. There is a possibility of frequent low water. How cruel it can be we found out in 2000 and 2001, when the water was not enough even for irrigation, Amudarya river had not even flew to Aral Sea this years, and Syrdarya basin rivers’ drainage was significantly lower than its average year values.
But there is another risk. Even if the drainage of the rivers remains in previous volume, its users will not be only 40 million people, who live in Syrdarya and Amudarya rivers basin, people amount will rise up to 55-60 million. – Afghanistan will claim its share of Amudarya water. The area of irrigated land will increase. That is why the problem of climate change consequences estimation and searching of ways of adaptation is difficult and needs calculation of many factors.