Avoid air conditioning. If home air conditioning were not wide-spread, far fewer yankees would move south. Also the environment would be better off. First air conditioning was a major factor in the ozone hole. While fewer people would live in the south in the summer, more people would be hitting the beaches, which are usually cooler than the inner south. Second, there would be less global warming. Unlike heating, which would have a negative feedback with global cooling, air conditioning has a positive feedback. While air conditioning cools a house, it heats the surrounding air by more. Not only does it use alot of fossil fuel it makes the surrounding air evenhoter. If we could butterfly air conditioning and continue the use of railroads, we might not be talking about global warming.