Mainly emitted by farmed soil and intensified by fertiliser, it accounts for 9 percent of greenhouse gas emissions from human activity.

"We have to do a balancing act for nitrous oxide" to curb both hunger and global warming, said Nick Watmough of the British University of East Anglia. The University will set a new group on Feb. 22 to study ways to limit emissions from the gas.

"We live in a hungry world and we live in a world that needs to put fertilisers on the soil to grow crops," he told Reuters.

He said researchers needed to engage those involved in food production, as well as with policymakers, to find ways to cut nitrous oxide emissions while also preventing food shortages.

Companies in the university's new Nitrous Oxide Focus Group would include Marks & Spencer and Unilever. The group, also including British officials and environmentalists, should come up with new ideas in the coming years.

The University said nitrous oxide, which causes euphoria when breathed and is sometimes used as an anaesthetic, was "no laughing matter".

"Nitrous oxide is a forgotten greenhouse gas, in the sense that much of the focus in the media has been on rising carbon dioxide emissions," Watmough said.

Cutting the use of fertilisers, which feed bacteria in the soils that produce nitrous oxide, is not always the solution.

"There are significant advantages to fast-growing crops," Watmouth said, noting that plants soak up carbon dioxide as they grow.

Scientists needed a better understanding of enzymes and bacteria in the soil that generate nitrous oxide when they feed on fertilisers, he said.