What if by the irrigation and flooding of areas of low altitude or the use of dams in the more arid and deserted areas of the world. If that would offset some of the effects of Global Warming, not only locally or in the longer term globally. An exaggerated example of this would be maybe a water mass the size of Montana were to be placed in the Sahara desert. I am positive that there would be immediate positive effects in an area like that. But would it also benefit the globe by reflecting more of the suns rays?