If man is the cause of Lake Mead drying up, let's not forget that man is also the reason Lake Mead exists and all the benefits derived from it. Global warming may indeed be the results of man's industrial age, but would you give up the benefits we have to have the polar ice caps back? Yes global warming is a concern, but man is an intelligent and adaptable creature. Given time we will either come up with a solution or adapt to a world with high oceans and warmer climates. Don't let Al Gore scare you into thinking man is on the brink of extinction.