Divorced households spend more per person per month for electricity compared with married households, because in married households it's more likely that multiple people watch the same television, listen to the same radio, cook on the same stove, or eat under the same lights.
That means some 6.9 billion U.S. dollars in extra utility costs per year, Liu calculated, plus an added 3.6 billion U.S. for water, in addition to other costs such as land use.
And it isn't just the United States.
Liu looked at 11 other countries, including Brazil, Costa Rica, Ecuador, Greece, Mexico, and South Africa between 1998 and 2002.
If divorced households in these countries alone had combined to include the same average household size as married households, there would have been a million fewer energy- and water-consuming households.
Liu stressed that he isn't condemning divorce: "Some people really need to get divorces."
But he added, "one way to be more environmentally friendly is to live with other people, and that will reduce the impact."
Living in a traditional household is not the only way to reap these savings—Shaker communities and even hippie communes are more efficient than living alone.
Less People, More Households
Liu was studying the ecology of areas with declining population and noticed that even where the total number of people was less, the number of households was increasing. He wondered why.
The answers, he found, seems to be divorce, demographic shifts—such as people remaining single longer—and the demise of multigenerational households.
"We found the proportion of divorced households has increased rapidly across the globe," he said.
So he set out to measure the difference divorce makes in terms of energy and water, land use, and construction materials.
The research was funded by the National Science Foundation, the National Institutes of Health, and the Michigan Agricultural Experiment Station.
Copyright 2007 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
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