Unless the world goes vegetarian overnight, there will be a continued need to reduce the greenhouse gas emissions produced from farming livestock - an extensive and growing part of the agriculture industry.
As it turns out, this could be achievable without sacrificing economic and social benefits, according to a new review article published today in Nature Climate Change.
An international team lead by Dr Mario Herrero from CSIRO’s Agriculture department has quantified the mitigation potential of changes in the livestock industry, from both the suppliers’ perspective and the role of consumers.
"Livestock emits - depending on the numbers you look at - about 18 per cent of all greenhouse gasses produced, and this is significant. But at the same time it has a huge mitigation potential," says Herrero.
“New management practices such as rotational grazing and dietary supplements can increase livestock production and reduce greenhouse gas emissions."
According to the researchers, the livestock sector is using 30 per cent of the planet’s terrestrial land area for grazing, and one-third of all cropland is devoted to animal feed.
It’s an economically important sector, as it contributes up to 50 per cent of the world’s agricultural GDP, supporting about 1.3 billion people globally - both producers and retailers. Furthermore, it appears to be steadily growing.
“As people get richer, they want to consume more animal products,” says Herrero. “If you look at most of the projections available, the amount of milk and meat that we are going to need in the future is in the order of 70 per cent more by 2050.”
“With such growth, can we get to a system where we can produce at a lower environmental footprint? That's what drove our interest.”
Incentives for suppliers
There are two sides to mitigating greenhouse gases from livestock. One pertains to the supply side, with change of practices and incentives for farmers to minimise greenhouse gasses. While there are many options that could mitigate gas emissions, the researchers note that currently the adoption rates are low.
“One of the lessons is that first we need to increase the adoption of these practices, we need to work on getting the economic incentives right,” Herrero stresses. “This could range from better credit facilities, having systems of incentives for rewarding environmental performance.”
The review article also points to feasible, tested technical practices, such as improving the digestibility of livestock feed and using feed additives - chemical compounds that are proven to cut down methane emissions from ruminant animals.
Small-scale and subsistence farming has a role here, too - the researchers note that improving animal productivity and health is one of the most effective approaches for reducing greenhouse gas emissions “per unit of product.” This would mean moving away from unsustainable intensive farming practices.
Eat less meat
The other side of the coin naturally applies to customers - the people who could potentially choose to eat less meat, thus reducing demand. However, it’s not as easy as just telling people what to eat, because incentives for consumers are varied, and dietary choices often revolve around health.
Herrero points out that when people decide to cut their heart disease risk by eating less meat, there’s a co-benefit of greenhouse gas mitigation, because less land is needed for livestock. This land can then be used for planting trees or growing crops, instead of producing more methane.
This review has come out on the same day as a study by Oxford Martin School researchers, published in Proceedings of the National Academy of Sciences - it has estimated the global health and climate change impacts of a move to a more plant-based diet. According to the study, a widespread adoption of a vegan diet could help avoid more than 8 million deaths by 2050.