Toronto, Aug 18 - Methane emission by plants in dry or drought prone areas could aggravate global warming more than previously suspected, says a new study.

A University of Calgary (U-C) study warns that plants exposed to environmental factors -- rising temperature, drought and ultraviolet-B radiation -- show enhanced methane emissions.

Methane is a very potent greenhouse gas -- 23 times more effective in trapping heat than carbon dioxide.

'Most studies just look at one factor. We wanted to mix a few of the environmental factors that are part of the climate change scenario to study a more true-to-life impact climate change has on plants,' says David Reid, professor at U-C who co-authored the paper with M. Qaderi.

Reid and Qaderi analysed methane emissions from six crops -- faba bean, sunflower, pea, canola, barley and wheat -- that were exposed to rising temperature, ultraviolet-B radiation and water stress (drought).