Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations

The rapid rise of caspian sea water level (about 2.25 meters since 1978) has caused much concern to all fivesurrounding countries, primarily because flooding has destroyed or damaged buildings and other engineeringstructures, roads, beaches and farm lands in the coastal zone. given that climate, and more specifically climatechange, is a primary factor influencing oscillations in caspian sea water levels, the effect of different climate changescenarios on future caspian sea levels was simulated. variations in environmental parameters such as temperature,precipitation, evaporation, atmospheric carbon dioxide and water level oscillations of the caspian sea andsurrounding regions, are considered for both past (1951-2006) and future (2025-2100) time frames. the output ofthe ukhadgem general circulation model and five alternative scenarios including a1cai, biasf, bimes wre450 andwre750 were extracted using the magicc scengen model software (version 5.3). the results suggest that themean temperature of the caspian sea region (bandar-e-anzali monitoring site) has increased by ca. 0.17°c perdecade under the impacts of atmospheric carbon dioxide changes (r=0.21). the caspian sea water level hasincreased by ca. +36cm per decade (r=0.82) between the years 1951-2006. mean results from all modeledscenarios indicate that the temperature will increase by ca. 3.64°c and precipitation will decrease by ca. 10%(182 mm) over the caspian sea, whilst in the volga river basin, temperatures are projected to increase by ca.4.78°c and precipitation increase by ca. 12% (58 mm) by the year 2100. finally, statistical modeling of thecaspian sea water levels project future water level increases of between 86 cm and 163 cm by the years2075 and 2100, respectively.