9. COOL AND COVER FOODS BEFORE STORING THEM. When you place hot or moisture-rich foods like soups or leafy vegetables in your refrigerator or freezer, water can evaporate from them, adding moisture to the air inside. According to the U.S. Department of Energy, this makes it harder for your fridge or freezer to maintain cold temperatures. To lock in moisture, let hot foods cool on their own (for one to two hours—any longer and they could spoil) then cover them to refrigerate or freeze. And wrap leafy vegetables in a hand towel or a reusable bag before refrigerating.
EVEN GREENER: Store food in a reusable container or cover with a lid or plate (rather than foil or plastic wrap) to minimize waste.
10. USE THE AIRPORT BATHROOM BEFORE BOARDING A PLANE. Before takeoff and after landing, airplane toilets are sometimes powered by gasoline—and some planes even use gas-powered motors (rather than the suction created by air pressure) to flush during the entire trip. According to China Southern Airlines, each fuel-powered flush uses one liter of gas—that’s enough energy to drive a car six miles— and releases more than five pounds of carbon dioxide into the air. To save fuel, make a point of using the airport bathroom before you board.
EVEN GREENER: Offset your flight’s carbon emissions by donating to renewable energy projects like wind farms. Sites like nativeenergy.com or terrapass.com allow you to calculate how much carbon dioxide your flight generated and fund the creation of an equal amount of green energy.
11. INSTALL YOUR AIR CONDITIONER IN A SHADED WINDOW. Air-conditioning units placed in direct sunlight have to work harder and end up using 10 percent more energy, according to the U.S. Department of Energy Efficiency and Renewable Energy. Move the unit to a window that’s shaded by trees or other buildings, or one that faces north or east and will be out of direct sunlight during the hottest part of the day.
EVEN GREENER: Forego your air conditioner for a ceiling or window fan, which use as little as 50 to 200 watts every hour (as opposed to the 3,500 watts used by some air conditioning units).
12. USE POWDER DETERGENTS INSTEAD OF LIQUID ONES. Liquid detergents contain up to 80 percent water (even concentrated formulas are about 40 to 60 percent water). Since your washing machine or dishwasher will add water anyway, choosing powdered detergents saves water. Another benefit: Powdered detergents usually come in biodegradable cardboard containers rather than oil-based plastic ones.
EVEN GREENER: Avoid extra packaging by choosing loose powder over individually wrapped tablets or by refilling an old container with bulk detergent from a health food store.