29. Remove the tie

How can a tie help fight climate change? When you leave it at home. In the "cool biz" summer of 2005, Japanese salarymen swapped their trademark dark blue business suits for open collars and light tropical colors. It was all part of the Japanese government's effort to save energy by keeping its office temperatures at 82.4°F throughout the summer.

The policy caused sartorial confusion but did make a dent in Japan's rising carbon emissions. In one summer, Japan cut an estimated 79,000 tons of CO2. If U.S. businesses eased off on their arctic-level air-conditioning, the gains could be significant. Time to make every summer day casual Friday?