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May 07, 2012
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Holy cow! Dino flatulence may have changed ancient climate
May 7, 2012
Courtesy of Cell Press
and World
Science staff
Never mind cows: dinosaurs passing gas could have released enough climate-altering methane gas to warm the
prehistoric world, according to newly published calculations.
While many a student has snickered over the observation that flatulating livestock contribute to the atmospheric greenhouse gases blamed for global warming today, dealing with a hulking apatosaurus
(a.k.a. brontosaurus) with indigestion might have been no laughing matter.
The new research published in the May 8 issue of the research journal
Current Biology also suggests that this beast and its
kin—giant dinosaurs known as sauropods—could have harbored enough methane-making microbes in their guts to make a substantial climate impact.
“A simple mathematical model suggests that the microbes living in sauropod dinosaurs may have produced enough methane to have an important effect,” said Dave Wilkinson of Liverpool John Moores University in the
U.K. “Our calculations suggest that these dinosaurs could have produced more methane than all modern sources—both natural and man-made—put together.”
Methane and other greenhouse gases tend to warm the climate by trapping heat in the atmosphere, scientists say.
Distinctive for their enormous size and long necks, sauropods were widespread about 150 million years ago. As in cows, methane-producing microbes aided the sauropods’ digestion by fermenting their plant food. Wilkinson and study coauthor Graeme Ruxton from the University of St Andrews, U.K. were studying sauropod ecology when a question dawned on them: If modern cows produce enough methane gas to be of interest to climate scientists, what about sauropods? They teamed up with methane expert Euan Nisbet at the University of London to work out the numbers.
“Clearly, trying to estimate this for animals that are unlike anything living has to be a bit of an educated guess,” Wilkinson said.
Physiologists have studied methane production from a range of modern animals to derive equations that predict methane production from animals of different sizes. It turns out those calculations depend only on the animal’s weight. A medium-sized sauropod weighed over 20 tons. Using available estimates of population densities, the scientists calculated global methane emissions from sauropods to have been 520 million metric tons yearly, comparable to total modern methane emissions.
Before modern industry took off, methane emissions were roughly 200 million metric tons a year. Modern ruminant animals, including cows, goats, giraffes, and others, produce about one-fourth to one-half that amount. The study’s conclusions not only show “just how strange and wonderful the workings of the planet are,” but also serve as a useful reminder for the importance of microbes and methane for global climate, the researchers wrote.
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Never mind cows: dinosaurs passing gas could have released enough climate-altering methane gas to warm the world, according to newly published calculations. While many a student has snickered over the observation that flatulating livestock contribute to the atmospheric greenhouse gases blamed for global warming today, dealing with a hulking apatosaurus (brontosaurus) with indigestion might have been no laughing matter. The new research published in the May 8 issue of the research journal Current Biology also suggests that this beast and its relatives—giants known as sauropods—could have harbored enough methane-making microbes in their guts to make a substantial climate impact. “A simple mathematical model suggests that the microbes living in sauropod dinosaurs may have produced enough methane to have an important effect,” said Dave Wilkinson of Liverpool John Moores University in the U.K.. “Our calculations suggest that these dinosaurs could have produced more methane than all modern sources—both natural and man-made—put together.” Methane and other greenhouse gases tend to warm the climate by trapping heat in the atmosphere, scientists say. Distinctive for their enormous size and long necks, sauropods were widespread about 150 million years ago. As in cows, methane-producing microbes aided the sauropods’ digestion by fermenting their plant food. Wilkinson and study coauthor Graeme Ruxton from the University of St Andrews, U.K. were studying sauropod ecology when a question dawned on them: If modern cows produce enough methane gas to be of interest to climate scientists, what about sauropods? They teamed up with methane expert Euan Nisbet at the University of London to work out the numbers. “Clearly, trying to estimate this for animals that are unlike anything living has to be a bit of an educated guess,” Wilkinson said. Animal physiologists have studied methane production from a range of modern animals to derive equations that predict methane production from animals of different sizes. It turns out those calculations depend only on the animal’s weight. A medium-sized sauropod weighed over 20 tons. Using available estimates of population densities, the scientists calculated global methane emissions from sauropods to have been 520 million metric tons yearly, comparable to total modern methane emissions. Before modern industry took off, methane emissions were roughly 200 million metric tons a year. Modern ruminant animals, including cows, goats, giraffes, and others, produce about one-fourth to one-half that amount. The study’s conclusions not only show “just how strange and wonderful the workings of the planet are,” but also serve as a useful reminder for the importance of microbes and methane for global climate, the researchers wrote.