EAST LANSING, Mich. — Want to save the planet from global warming? Then try saving your marriage.

That’s the message of Jianguo Liu, a distinguished professor of ecology and the Rachel Carson Chair in Sustainability at Michigan State University.

Liu’s damning analysis of the heavy negative effects divorces have on the environment was published in early December in the online edition of the Proceedings of the National Academy of Sciences.

Liu said he and his team of scientists collected data about consumption of energy and production of waste in 11 countries, including the United States, going back to the 1970s.

In the United States alone, Liu concluded, divorce results in $6.9 billion in additional household energy consumption, and $3.6 billion worth of additional water usage.

“If you ride a bike or use efficient light bulbs or turn down the heat a few degrees, all of those things will help the environment,” Liu said. “But a divorce will easily offset those activities. It has an enormous impact.”

That’s because a divorce usually results in one household becoming two, Liu explained. Liu said he began the research after learning that the number of households has been increasing globally in recent decades at a far greater rate than population growth.

“If you have two parents and five children in a room, they’re all getting the same benefit from one light bulb, one TV, the heating system in the house,” Liu said. “When a divorce occurs, at least two of all those things are needed for the same people.”

Additionally, Liu said, a divorce often results in parents driving children great distances back and forth in order that they can visit both households. He said divorced families are likely to have more cars than when they lived as one.

“There are many other things as well,” Liu said. “You have more use of land, more use of construction material because there’s suddenly the need for another home. It results in more furniture, more appliances, another microwave, another air conditioner and refrigerator. Basically, instead of one family sharing resources, you split the family and the same number of people requires twice the resources.”

Environmentalists React

But don’t expect those thousands of global warming websites and brochures to begin adding “avoid divorce” or “take marriage seriously” to the lists that say “ride a bike,” “drive a hybrid car” or “use energy efficient light bulbs.”

“People doing research on environmental issues are very surprised by this, and they don’t realize the connection between divorce and the environment,” Liu said. “Even people who care very deeply about the environment don’t make this connection.”

Tony Kreindler, media director for climate at the headquarters of Environmental Defense in Washington, D.C., said Liu’s study results were “outside my area of expertise.”

Jesus Mena, California media director for Environmental Defense, laughed when he was asked about the connection between divorce and global warming. He said the question resulted in “befuddlement” among his colleagues when it first arrived by e-mail.

“I suppose divorce results in a lot of heated exchanges,” Mena quipped, declining to address the study’s findings.

The Catechism of the Catholic Church teaches that “Divorce is a grave offense against the natural law.” It also states that “divorce is immoral also because it introduces disorder into the family and into society,” a disorder that it states “makes it (divorce) truly a plague on society” (No. 2384).

The Catechism says one spouse can be the innocent victim of divorce if unjustly abandoned by another, and therefore has not contravened moral law.

At least one leading Catholic advocate of traditional marriage, however, isn’t impressed by Liu’s findings. Maggie Gallagher, president of the Washington-based Institute for Marriage and Public Policy, agreed that divorce causes disorder and wreaks havoc in society.

But she’s not “a big fan of that study,” she said.

“The logic of the study suggests that divorced fathers would help the environment by abandoning their children, rather than driving across town to see them,” she said. “It would suggest that unmarried couples are better to live together rather than to date and maintain separate households. To endorse this study I’d have to endorse the underlying assumption that we should define the problem of global warming as anything that increases the number of people or houses on the planet.”

Gallagher said an ideological belief that more human activity warms the planet is the reason China wants environmental energy credits as a reward for its one-child-only policy.

The divorce industry may have a mixed reaction to Liu’s study.

Chicago divorce lawyer Corri Fetman shocked the city last summer when she paid for a billboard that said: “Life’s short. Get a divorce.” It featured a scantily clad woman on one side of the sign, and a bare-chested man on the other.

“She has decided not to comment on (Liu’s study),” said Fetman’s assistant, hanging up the phone.

Divorce lawyer Sharyn Sooho, a founding partner of Divorcenet.com, said Liu’s study is absolutely correct: Divorce wreaks havoc not only with children and the community, but with the environment. Marriage, she said, naturally results in an efficient sharing of resources.

“In 30 years of practicing divorce law, I don’t know why I didn’t think of that,” Sooho said. “It’s absolutely true. I know this just from looking at the costs. In most cases, divorce creates an unaffordable, untenable situation for young adults and their children. They cannot afford two homes, and two of everything else.”

Sooho said she has spent her career trying to assist with good outcomes, and sometimes the best outcome is reconciliation of the marriage. She can foresee playing a “save the planet” card at some point to encourage reconciliation, but she doubts it will work.

“I talk to people who I think should persevere in the marriage,” Sooho said. “Usually they say ‘You’re not a marriage counselor,’ and then tell me to get back to the business of undoing the marriage. By the time they’re talking to lawyers it’s usually too late, and I would say this is probably the case even for those who care deeply about the planet. Getting out of the marriage will take precedence.”

Jeff Cottrill, managing editor of Toronto-based Divorce magazine, said it would take two “extreme, hippie-like environmentalists” to reconcile a marriage out of concern for Mother Earth.

“I can see where the study is coming from,” Cottrill said. “But divorce is such an emotionally overpowering event. Emotion is going to override concerns about the environment every time.”