Dinosaur Gas May Have Caused Ancient Global Warming
The Earth was approximately 18 degrees Fahrenheit (10 degrees Celsius) warmer 150 million years ago, and according to a new study, dinosaur gas may have been the cause. Researchers found that giant dinosaurs could have contributed millions of metric tons of methane to the atmosphere and been a key factor in long-ago global warming.
Methane, which is released through flatulence, is a key greenhouse gas, and cows and other livestock contribute many millions of tons of methane to the atmosphere every year, according to the study.
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Researchers extrapolated the amount of gas cows release to figure out how much methane sauropods, such as the 50,000-pound (23,000-kilogram) apatosaurus, would have released.
"Cows today produce something like 50-100 [million tons] per year," David Wilkinson, study author and researcher from John Moore's University in Liverpool, told BBC News. "Our best estimate for sauropods is around 520 [million tons]."
Greenhouse gases such as methane, carbon dioxide, nitrous oxide and ozone trap heat in the atmosphere and act as a blanket, raising temperatures and causing climate change. Global temperature increases could affect sea levels, crops and animal habitats. Scientists expect heat waves, cold snaps, hurricanes and other extreme weather events to increase as temperatures increase, according to EPA officials.
Microbes living in the dinosaur's gut would have caused intense gas, according to the study. Sauropods were herbivores, and the microbes probably aided in digestion by fermenting the plants, much as they do in cows.
"All vertebrates that feed on leaves use microbes to help digest these, and usually give off methane," Wilkinson told MSNBC. "This includes both mammals and reptiles. Although details vary within groups, everything around today does this, so the assumption is larger herbivorous dinosaurs did as well."
Researchers said the output of the giant dinosaurs could have rivaled the total amount of methane produced by the world today.
"A simple mathematical model suggests that the microbes living in sauropod dinosaurs may have produced enough methane to have an important effect on the Mesozoic climate," Wilkinson said in a statement. "Indeed, our calculations suggest that these dinosaurs could have produced more methane than all modern sources -- both natural and man-made -- put together."
Current methane emissions, both from animals and from human sources such as meat production, total approximately 500 million tons annually. The comparison is striking, and methane emissions in the Mesozoic era were likely higher than the researchers estimated, Wilkinson said.
"There were other sources of methane in the Mesozoic, so total methane level would probably have been much higher than now," he told BBC News.
Wilkinson stressed that the study did not prove conclusively that sauropod gas caused ancient global warming, but said it is possible it did.
"What our simple calculations show is that, yes, it could. It's a real possibility. But we don't show that it did happen," he told MSNBC. "That would require much more work, and indeed it may be impossible to completely prove this without a time machine."
The journal Current Biology will publish the study on Tuesday.
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