Toronto: 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).
What they found is troubling. These stresses caused plants to emit more methane. In a warmer, drier world methane might be a bigger contributor in global warming than previously thought.
When it comes to the greenhouse effect, methane could be considered the misunderstood and often overlooked orphan greenhouse gas, said an U-C release.
Its concentrations have more than doubled since pre-industrial times. While the growth rate of methane concentrations has slowed since the early 1990s, some scientists say this is only a temporary pause.
These findings were published online in Physiologia Plantarum.