Did Flatulant Dinosaurs Really Cause Climate Change?

Illustration by Newsweek (source photo): Mark Garlick / Science Photo Library-Getty Images

A strong wind is blowing across the field of paleontology, and it stinks. According to a short paper by three British academics, sauropods—veggie-munching dinosaurs that grew especially large in the Jurassic era—could have burped and farted enough methane into the atmosphere to have warmed the earth's climate.

The theory starts not so much with dinosaurs (none of the academics is a paleontologist), but with the microbes that enable cows to digest plant material. Since the process produces considerable quantities of methane, a potent greenhouse gas, David Wilkinson, an environmental scientist at Liverpool John Moores University, and colleagues at the Universities of Glasgow and London "wondered what would happen with animals that are so weird by the standards of today," he says.

Their conclusion? Stand downwind of a lumbering Apatosaurus louisae, formerly known as a brontosaurus, and expect to be gassed by a 2,675-liter gale of methane per day. Model that across the world, and dinosaur flatulence produced between 500 million and 600 million tons of methane per year.

There are, however, some rather Jurassic-size caveats. "These are theoretical guesses," stresses Wilkinson. "We had no option [but] to do what I tell my students not to do, which is project." In other words, just because the average apatosaurus is four times the size of an elephant doesn't mean it's going to break four times as much wind.

Actual dinosaur experts are equally circumspect—especially about the impact on the earth's climate, given that these dinosaurs lived through an astounding period of global change that saw the continents separate and the Atlantic Ocean form.

"I don't think it's unreasonable to say that methane production by sauropods may have played a role in the control of global temperatures, but how much is still an open question," says John Whitlock, a paleontologist at the University of British Columbia. "You're looking at a window of time nearly 200 million years long, over which major variations in global temperature and aridity occurred."

Wilkinson is quick to agree, noting that many other factors need to be considered. "What we have demonstrated," he says, "is that methane emissions had a measurable, but not dominant, effect on climate—perhaps a half to 1 degree Celsius."

But dangerously flatulent animals aren't just preancient history. Methane emissions from cattle are the issue today, accounting for 2 percent of all greenhouse gases. (One way to minimize these emissions: adding oregano or curry powder to the cows' feed.) If anything, the study reminds us that every creature—not just man—can affect the earth's climate.