It’s food for climate conscious consumers. A strain of rice has been genetically engineered to produce less methane.

 

Rice agriculture is responsible for between 7 and 17 per cent of human-induced methane emissions. Sugars produced during photosynthesis leak into the soil via the roots, where they are used up by methane-producing soil microorganisms.

 

Chuanxin Sun from the Swedish University of Agricultural Sciences in Uppsala and his colleagues in China and the US have now engineered rice that stores more sugar in its grains and stems. In a three-year-long trial, the rice grew well and led to drops in paddy field methane emissions.

 

The methane reductions were most pronounced in the summer, when the high temperatures stimulated higher production of sugars.

 

Sun believes that reducing methane emissions from rice agriculture could be a huge help in mitigating climate change.

 

Charles Rice of Kansas State University in Manhattan agrees. He recently contributed to a 2014 IPCC report on mitigating climate change. If we can halve the methane emissions of rice agriculture, we will have met the targets highlighted in that report, says Rice.

 

Changing rice farming practices has already reduced emissions. For instance, draining rice paddy fields just once rather than several times during the growing season has been estimated to drastically reduce methane emissions by stopping the growth of methane-producing microorganisms.

 

Piers Forster at the University of Leeds, UK, who contributed to the 2007 IPCC report on mitigating climate change, believes that the genetically engineered rice could help to reduce emissions “only as part of a wider adoption of new farming methods”.

 

Sun’s team is now collaborating with other researchers to try to model the impact of switching to this engineered rice on global methane emissions and climate change.

 

But the fact that this rice is genetically modified could prove to be a sticking point in introducing it to farmers and the general population. “It’s quite a sensitive issue”, says Sun. This means farmers can’t culture the low-methane rice at the moment.

 

However, Sun and his colleagues are attempting to overcome this issue by looking into producing low-methane rice through conventional breeding methods. “We want to use the same principle to try to breed new rice cultivars and try to solve the methane emission problem,” he says.

 

 

PHOTO: Rice, head down in embarrassment.

CREDIT: Pascal Deloche/Godong/Panos.