How do you not click on this headline?

WANT TO GO GREEN? STAY MARRIED
Divorced Households Have Negative Impact on Environment, Study Finds

[…]

The reason is simple — it's all about efficiency, says Jianguo Liu, lead author of the study who has the Rachel Carson chair in ecological sustainability at the university's department of fisheries and wildlife.

"In the divorced households, the number of people is smaller than in married households," Liu told ABCNEWS.com. "The resource efficiency used per person is much lower than in married households."

While the headline was initially something of an eye-catcher, the rationale is comparatively – almost stupidly - simple. Obviously certain resources, such as heat or electricity, have an overhead – almost every household, no matter how small, has certain appliances, like a refrigerator. But very few households, no matter how large, have more than one refrigerator. An economist would say that the marginal use of these resources is small, so by packing more people into a household you increase the energy efficiency.

Our Catholic friends will relish this report, since a cursory understanding of the results seems to give them a carte blanche for their favorite activity: dropping babies. O course some other methods of increasing household size, such as having a bunch of extra kids, has the same effect on efficiency, but still increases total resource use, thereby having a negative environmental impact.

Still, I can think of two interesting implications for the research. The first is based on the fact that in many other parts of the world, especially Asian and Hispanic countries, families tend to live together in larger groups. Married couples often live under the same roof as their parents and even their grandparents. Independent of different population growth rates between these cultures and ours, this illustrates a key way in which the per capita energy use of these collectivist cultures differs from the individualist culture of the United States and many European countries. It may be terrifically uncool for you and your girlfriend to live in Mom & Dad’s basement, but it is good for the environment.

The second is the always politically volatile issue of same-sex marriage. I have my doubts that prohibiting a couple from having a legally recognized union has much effect on whether they live together (how many same-sex couples do you know that too socially conservative to move in together out of wedlock? Yeah, me neither), but the increased challenges that same-sex couples face in adopting children (which are at least partially related to their ability to form a legal union) should make it less likely that their households will be large and therefore more efficient.

In conclusion, if divorce is an environmental issue, then so is same-sex marriage.