Climate Change and the expected impacts of Global Warming on global water resources will have pronounced effects worldwide in the 21st century. To see any change some references must be used and in this case as explained here the 20th century will be used reference for comparison. Among key processes in the global water cycle that are undergoing dramatic changes in dynamics and rates are: evapotranspiration; soil moisture; surface water flow and ground water levels. Changes in the dynamics and rates of these  processes will have direct and indirect effects on the vegetation cover, forest, agriculture and farming as well as remarkable impacts on the global water supply with feedback effects on agriculture, industry and basic human need including drinking water .

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