Charle Gibson's report on global warming tonight?

Leading scientists say that the southwest united states would be locked into a long term drought? Duh, isn't the southwest united states mostly desert? hasn't it been desert since the great oceans receeded millions of years ago? Who are these Leading scientists? They claim that countries in africa would face famines. I am in my forties and since i can remember, african countries have suffered from famine. I used to collect money for unicef to send over there presumably to buy food for those people. Who are these scientists? Where is the proof? This is the biggest lie ever perpetrated upon the people of the world! It is a lie!!!!!