Assessing Climate Change by Multi-Criteria Decision-Making Approach

General circulation models (GCMs) are an important tool in the assessment of climate change. These numerical coupled models represent various earth systems including the atmosphere, oceans, land surface and sea-ice and offer considerable potential for the study of climate change and variability. However, they remain relatively coarse in resolution and are unable to resolve significant subgrid scale features such as topography, clouds and land use. Bridging the gap between the resolution of climate models and regional and local scale processes represents a considerable problem for the impact assessment of climate change. Thus, considerable effort in the climate community has focussed on the development of techniques to bridge the gap, known as ‘downscaling’. In this study two statistical downscaling techniques (lars WG and SDSM) and Proportional Downscaling method have been sued , which are combination to TOPSIS approach.The result shows SDSM is more ability technique of downscaling. And climate change will reduce monthly rainfalls up to 39% and increase the temperatures up to 2 °C.