A GROWN moose belches out methane gas equivalent to 2100kg of...

A GROWN moose belches out methane gas equivalent to 2100kg of carbon dioxide a year, contributing to global warming, Norwegian researchers say.

That is more than twice the amount of CO2 emitted on a round-trip flight across the Atlantic Ocean from Oslo to the Chilean capital Santiago, according to Scandinavian Airlines.

"An adult moose emits about 100 kilograms of methane gas a year. But methane gas is much stronger than carbon dioxide, so to get the equivalent you have to multiply by 21,'' professor Odd Harstad at the Norwegian University of Life Sciences said.

With an estimated 140,000 moose roaming Norway's forests, that is a total of of 294,000,000kg of CO2 per year.

But Prof Harstad said that was no reason to begin killing off the entire moose population.

"Moose have very important functions in nature. They are ruminants that eat the grass. If we don't have ruminants, we have too much grass and that changes the landscape and has consequences for the flora and fauna,'' he said.

Prof Harstad said the figure of 100kg of methane gas was a rough estimate based on earlier calculations for beef cows in Norway.

As is the case with cows and other ruminants, methane is produced from the microbes in the moose's stomach which help break down the roughage they eat.

Because methane gas is stronger than carbon dioxide, it is considered even more harmful to the environment. Both methane and carbon dioxide are so-called greenhouses gases, one of the main causes of global warming