Turn Down Your Water-Heater Thermostat

Such thermostats are usually set to 140 degrees, although 120 is usually enough.
Every ten-degree reduction saves 600 pounds of CO2 per year for an electric heater, or 440 pounds for a gas heater.
If every household in the U.S. turned down its water-heater thermostat by 20 degrees, we could prevent more than 45 million tons of CO2 emissions per year—an amount equal to the total annual emissions from, for example, Kuwait or Libya.