Dinosaur Greenhouse Effect?

Flatulence from dinosaurs might have aggravated the “greenhouse effect” that warmed Earth’s prehistoric climate, say scientists who studied the giant reptiles’ fossilized dung. “Gas from dinosaurs includes methane that may have been a minor contributor to global warming 75 million to 80 million years ago,” said Simon Brassell, a geochemist at Indiana University in Bloomington.

The study, reported at the Geological Society of America meeting, revealed chemical signs of bacteria and algae in known and suspected dinosaur droppings collected in Montana. The presence of the microorganisms indicates plant-eating dinosaurs digested their food by fermenting it, a process that gives off methane.

Methane is a “greenhouse gas,” like the carbon dioxide exhaled by all animals and emitted by smokestacks. Such gases trap solar heat in the atmosphere, warming the planet just as glass traps heat inside a greenhouse.

But other scientists said that even if the dinosaurs produced methane, other sources, including extensive volcanic eruptions and rising sea levels, dominated.