While global warming appears to be a fact, its cause remains a mystery. Is it man-made, or is it just the cyclic nature of our atmosphere’s ambient temperature? The jury is still out.

And while we may not know what’s causing this phenomenon, there’s one cause we can safely rule out – dinosaur farts.

Stop snickering. A new study suggests that, back in the day, sauropods may have helped keep an already overheated world even warmer with their flatulence and burps. Together, they may have created a sort of a Mesozoic Dutch oven.

Sauropods – recognizable by their long necks, long tails and vaguely embarrassed expressions – were widespread around 150 million years ago. These big boys were ruminants – animals that had food fermenting in their guts for long periods. Modern ruminants include cows, goats and, apparently, the guy sitting next to me every time I fly.

This fermentation produces methane, a potent greenhouse gas with as much as 25 times the climate-warming potential as carbon dioxide. Methane is enough of a factor in modern global warming that scientists have figured out how much is emitted by plant-eating animals today. Cows alone produce nearly 100 tons a year of methane, and don’t get me talking about my new high-fiber diet.

A study by David Wilkinson of John Moores University in Liverpool, England, estimated that dinosaurs would have produced around 520 million tons of methane annually. That’s more than what’s produced by cattle, and somewhat less than produced by my grandfather, whose favorite meal is cabbage rolls and home-made beer.

Scientists say the ancient world was warmer – by about 18 degrees – than today, due to a number of factors. There were lots of volcanoes; also, swamps, shallow seas and plentiful plankton all helped boost greenhouse gas levels. Good thing there were no politicians.

However, it would be wrong to blame dinosaur flatulence for their extinction. Sauropods started showing up – and getting gassy – around 200 million years ago but didn’t die off until 65 million years ago. In other words: If farts killed, there would be a lot fewer men on the planet today.

Climate scientist Andrew Weaver of the University of Victoria in British Columbia said: “Frankly, methane emissions from dinosaurs is probably not the No. 1 thing we should be concerned about in modern society.”

Weaver may be right, but I bet he’s never ridden back to work with a brontosaurus after an all-you-can-eat Indian buffet. That might change his tune.