Measures include replacing tractors and combine-harvesters that use fossil fuels and breeding animals that emit less methane
BEIJING, May 6 (Reuters) - Using zero-emission farm machinery, breeding cattle that produce less methane and employing other new technologies could significantly cut greenhouse gas emissions from farms, a report by consultancy McKinsey said on Wednesday.
Agriculture, one of the world's biggest greenhouse gas contributors, is projected to account for about 20% of total emissions in the next 20 years, mostly methane produced by belching cattle and rice paddy fields.
Levels are rising as more food is grown to feed an expanding global population.
Environmental groups are urging consumers to reduce the amount of beef and lamb they eat, which could have the biggest impact on emissions, said the McKinsey report. Cutting food waste and reducing deforestation would also help, it said.
But farms could become more efficient, potentially cutting 4.6 billion tonnes of carbon dioxide equivalent a year by 2050 compared with emissions if no action were taken, or about 20% of reductions needed to help prevent the planet warming by more than 1.5 degrees Celsius.
"The first step in reducing emissions from agriculture is to produce food as efficiently as possible — that is, to change how we farm," the report said.
Of 25 measures highlighted, replacing tractors and combine harvesters that use fossil fuels with those with zero emissions would have the biggest impact, it said, although no vehicles were commercially available now.
Genetic selection and breeding farm animals that emit less methane could also have a large impact, it said.
Ruminant animals like cattle, sheep and buffalo produce methane when digesting food, generating more greenhouse gases than any country other than China in 2016.
Of the 19.9 billion tonnes of CO2 equivalent a year now emitted by agriculture, forestry and land use change, methane produced by cattle and other ruminant animals contributes about 8.3 billion tonnes, said McKinsey.
Breeders have already shown they could reduce by 5% per head the emission of methane, a more powerful greenhouse gas than CO2. Some feed additives also helped cut emissions, it said.
Better animal disease prevention could make protein production more efficient, including expanding veterinary services in Southeast Asia and Sub-Saharan Africa and developing vaccines for diseases, such as African swine fever which has killed millions of pigs around the world in recent years.
Better fertilisation could cut methane emissions from rice paddies, which now emit 2.1 billion tonnes of CO2 equivalent because of methane-producing bacteria in the water-logged soil.
Subsidies could support greater use of sulphate fertiliser that competes with the bacteria, the report said.
(Reporting by Dominique Patton; Editing by Edmund Blair)
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