Methane from cows used to grow vegetables
Government funding for extraction technology that takes climate-damaging gas from sealed cattle barn
‘Tackling methane really offers us a lot of opportunity. Because it has such a short halflife, it can have a massive impact’
‘My concern is this will encourage the keeping of animals inside. We should be doing more to treat those animals as sentient beings’
A CATTLE shed that collects methane from cows and uses their waste to grow fruit and vegetables has been given government backing in the fight to reduce greenhouse gas emissions.
The so-called GreenShed will look much like normal housing used to keep cattle inside over winter, but will be more airtight and include extraction technology to remove the methane and burn it on site.
Methane is a greenhouse gas 28 times more potent than carbon dioxide and has a powerful short-term impact. Methane from livestock accounts for around 6 per cent of the UK’s overall greenhouse gas emissions.
The Government is relying on technological solutions to cut significant amounts of methane from livestock farming, rather than focusing on changing diets to encourage less meat eating.
Energy needed for the GreenShed will be provided in part by burning the waste produced by the cows in an anaerobic digester attached to the shed.
The heat produced from that process will also be used in polytunnels that help crops to grow in a vertical farming system. The project is being led by Scotland’s Rural College, and is one of dozens to receive government backing from a fund to develop direct air capture of greenhouse gas emissions. “Tackling methane really offers us a lot of opportunity,” said Carole-Anne Duthie, the head of SRUC’s Beef and Sheep Research Centre. “Because it has such a short half-life [nine years], it can have a massive impact.”
Other recent inventions to tackle livestock methane include a mask that catches their burps, and the addition of seaweed into their diet, which can reduce the gas by up to 80 per cent.
The GreenShed researchers hope the tech will be ready in the next three to four years, and could provide a simple retrofit solution on farms where cattle are already kept inside over winter.
It will target cows during the final “finishing” months before they are sent for slaughter, when their methane emissions are highest.
The system is expected to add 5p to 15p for the farmer on the cost of producing a pound (0.5kg) of beef, at a time when they are facing increasing pressure on price.
The researchers are relying on a growing desire from consumers for food produced in a greener way, and a willingness to pay for it.
Although the project estimates it can cut up to 250 tons of CO2 equivalent gas from every cattle shed per year, it will not solve the problem of emissions from agriculture.
Burning the methane will produce CO2, while the shed cannot tackle the emissions produced during the rest of the cattle’s life.
There are also concerns that the feed given to cattle kept indoors is produced in areas that contribute to deforestation. Instead, increasing numbers of environmentally minded farmers are focusing on a regenerative agriculture system, in which hardy breeds of cattle are kept outside all year long, in a boost to their welfare and to soil health and its ability to store carbon.
“We need to tackle the climate and biodiversity crisis to have livestock outside and deliver the true benefits of a regenerative farming system,” said Martin Lines, the chairman of the Nature Friendly Farming Network. “My concern is this research will encourage the keeping of animals inside. We should be doing more to treat those animals as sentient beings.”
But its backers argue that the technology could provide a relatively simple way to reduce the emissions from cattle.
“It’s one of many in our potential toolkit to help solve the problem,” Ms Duthie said. “The key benefit is that you’re not asking for radical changes to how those farms are going to operate.”