The flatulence of a single sheep could power a small lorry for 25 miles a day, according to New Zealand scientist Dr David Lowe. Harnessing the methane output of 72 million sheep could solve the nation's fuel problems.
The belches of 10 cows are enough to heat a small house. Bovine flatulence adds 85 million tons of methane to the atmosphere each year.
Termites' eating habits add an estimated 150 million tons.
In 2008, the Swedish University for Agricultural Sciences in Uppsala received 3.8 million kronor ($590,000) in research funds to measure the methane released when cows belch.
The 20 cows involved in the study have different diets and wear a collar device measuring the methane level in the air around them.