August 18, 2009

Study: Stressed crops emit more methane

Canadian scientists say stressed crops emit more methane than thought and could result in a bigger global warming problem than currently forecast.

University of Calgary scientists said when crops are exposed to environmental factors that are part of climate change -- increased temperature, drought and ultraviolet-B radiation -- some plants show enhanced methane emissions. And methane is a significant 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, said Professor David Reid, who co-authored the study with research associate Mirwais Qaderi.

They analyzed methane emissions from six Canadian crops -- faba beans, sunflowers, peas, canola, barley and wheat. The scientists discovered the common climate change stresses caused the plants to emit more methane.

Our results are of importance in the whole climate warming discussion because methane is such a potent greenhouse warming gas, Qaderi said. It points to the possibility of yet another possible feedback (phenomenon) which could add to global warming.

The study appears in the early on-line edition of the journal Physiologia Plantarum.