If you thought divorce was bad for the kids, you should see what it does to the environment.

A study published Monday in the Proceedings of the National Academies of Science found that the inefficiency of divorced households resulted in an extra 73 billion kilowatt-hours of electricity use in the United States in 2005, about 7 percent of total home use.

“Turning on the light uses the same energy whether there are two people or four people in the room,” said lead author Jianguo Liu, an ecologist at Michigan State University.

The extra electricity generation spews more carbon dioxide into the air, exacerbating global warming.

“If you don’t want to get remarried, maybe move in with somebody you like,” said Liu, who just celebrated his 20th wedding anniversary.

Other obvious solutions include polygamy, commune living or roommates.

“I’m just a scientist trying to present the facts,” Liu said. “I’m not promoting one way or another.”

Liu used demographic data to estimate that divorced households, which account for about 15 percent of the 110 million U.S. households, used 3.7 rooms per person, compared with 2.5 for married households.

Looking at energy statistics, he calculated that divorced households spent 46 percent more per person on electricity than married households in 2005. They spent 56 percent more on water, according to the study, which also looked at the environmental effect of divorce in 11 other countries.

Jim Jewell, the chief operating officer of the Evangelical Environmental Network, a Christian conservation group based in Suwanee, Ga., said the study’s revelations, while interesting, will have no effect on the way he advises couples.

“When we sit down and counsel somebody not to get divorced, the fact that they would need two refrigerators would be so far down the line that it wouldn’t even register,” he said.

Environmentalists, however, said divorcees might look at their situation as a chance to lessen their environmental impact by moving in with family, getting a roommate or renting an apartment in the city.

“Think of divorce as an opportunity to scale back on the stuff you surround yourself with,” said Lisa Wise, executive director of the Center for a New American Dream, a nonprofit environmental organization in Takoma Park, Md.

But she added: “We clearly wouldn’t say, ‘Stay in an unhappy relationship because it’s better for the environment.’”