Some scientific findings are just too good to leave alone, even if you don’t know if they can ever be confirmed: Such is the case for a study saying that plant-eating dinosaurs could have emitted enough digestive methane to warm Earth’s climate 150 million years ago.
“It is known that the time of these dinosaurs was warmer than now,” said David Wilkinson…lead author of a paper on the subject appearing in the journal Current Biology. “This is explained usually by an enhanced greenhouse effect, mainly carbon dioxide. If we are correct, then methane from sauropods may have been a contributor to this greenhouse effect.”
Methane is a more potent greenhouse gas than carbon dioxide, and modern-day livestock are thought to be responsible for about a quarter of the methane released in the United States. Some say that the belches and flatulence of cattle, pigs and sheep are a significant contributor to the warming effect caused by greenhouse-gas emissions. So why wouldn’t it have been the same in the age of giant plant-eating dinosaurs, when global biomass density was at least several times what it is today..?
He and his colleagues ran the numbers, using what they saw as conservative estimates for the total amount of dinosaur biomass and methane production rates per kilogram of body mass. They came up with a figure of 520 million tons of methane emitted per year, which is more than total modern-day methane emissions from all sources, natural and industrial. The current estimate for total methane emission is around 500 million tons a year, with 50 to 100 million tons of that coming from ruminant animals such as cows and goats, Wilkinson said…
Biologists have found that most of the modern-day methane emissions from livestock come from belching rather than flatulence. Was it the same for dinosaurs? “We have no particular view which end of the sauropod the methane came out,” Wilkinson told me. “Could be either or both…”
“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 said. “That would require much more work, and indeed it may be impossible to completely prove this without a time machine.”
Perhaps we might send some sort of device back through — eventually. It needn’t have a human pilot. Just a sensor-sniffer of sorts.