BusinessMirror article on farting dinosaurs: "the global sauropod population pumped out 520 million tons of methane a year, about the same as the total current emissions of the greenhouse gas"

Mining our ecosystems: Overconsumption, climate change and biodiversity

Farting dinosaurs are probably not among the first thoughts that come to mind when thinking about today’s urgent global matters. Notwithstanding, looking back a few million years to the Mesozoic—the dinosaur era—precisely this could have been considered a high-ranking environmental problem.
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Thus, the global sauropod population pumped out 520 million tons of methane a year, about the same as the total current emissions of the greenhouse gas. Considering that methane is 20 times more potent than carbon dioxide, this warmed the planet by about 1 degree Celsius (oC), contributing to the fact that the climate in the dinosaur era was much warmer than today—for instance, there was no polar ice.

Sixty-five million years after the dinosaurs went extinct, we witness the same problem all over again, with livestock slightly different from sauropods: The 53 billion cows, sheep, pigs and chickens people eat every year produce 40 percent of the global methane and more than one-fifth of all greenhouse gases—even exceeding the transport sector.