The global warming link
Americans use more water than just about anyone on the planet, an average of 100 gallons per person per day. This high rate puts demands not only on water supplies, but also on energy production. Water heaters aren’t the only energy sink; water purification generates high energy costs. Our water supply and treatment facilities use about 56 billion kilowatt hours per year, enough electricity to keep five million homes running for a year.
The EPA says that if one in a hundred of us installs water efficient fixtures to reduce the amount of wastewater requiring treatment, we’d save 100 million kilowatt hours and avoid producing 80,000 tons of greenhouse gas emissions. For more on greenhouse gas emissions, see the Global Warming Guide .
The concept of the water footprint refers to how much water is used by people not only in their homes, but to produce the goods and services they consume. The internal footprint for a particular country refers to the amount of water that comes from within that country. The external footprint takes into account water used in other countries to produce goods and services that are then brought in.
Of course, a large portion goes to agriculture and food production. And industrial countries have a much larger water footprint. The U.S., for example, has an average water footprint of 2480 m3 per capita per year, more than three times that of China.
