* Photo: Michael Edwards * As a symbol of American profligacy, the air conditioner may rank second only to the automobile. Energy-sucking AC props up an unsustainable lifestyle in scorching desert cities like Phoenix, while the cheerful New Englander splitting wood and tending his potbelly stove is the epitome of ecological harmony MDASH so goes the green cant. But this stereotype gets it wrong. When it's 0 degrees outside, you've got to raise the indoor thermometer to 70 degrees. In 110-degree weather, you need to change the temperature by only 40 degrees to achieve the same comfort level. Since air-conditioning is inherently more efficient than heating (that is, it takes less energy to cool a given space by 1 degree than to heat it by the same amount), the difference has big implications for greenhouse gases.
In the Northeast, a typical house heated by fuel oil emits 13,000 pounds of CO2 annually. Cooling a similar dwelling in Phoenix produces only 900 pounds of CO2 a year. Air-conditioning wins on a national scale as well. Salving the summer swelter in the US produces 110 million metric tons of CO2 annually. Heating the country releases nearly eight times more carbon over the same period. Meanwhile, chilly Northeasterners can at least take heart in one thing: With global warming you can turn the heat down.
Related Inconvenient Truths: Get Ready to Rethink What it Means to Be Green 1: Live in Cities 2: A/C Is OK 3: Organics Are Not The Answer 4: Farm the Forests 5: China Is the Solution 6: Accept Genetic Engineering 7: Carbon Trading Doesn't Work 8: Embrace Nuclear Power 9: Used Cars — Not Hybrids 10: Prepare for the Worst
