Food production contributes 37 per cent of global greenhouse gas emissions, with animal-based foods accounting for more than a third of those. Such figures have led to calls for reducing meat consumption to fight climate change. But what impact is this having on the livestock sector?
Although there has been a shift towards plant-based foods and more sustainable sources of animal protein, such as chicken and farmed fish, in high-income countries, the demand for meat from low- and middle-income countries (LMICs) is continuing to rise.
“The world is not likely to iterate towards zero consumption of all animal proteins,” says Dominic Moran, Professor of Agricultural and Resource Economics in the University’s Global Academy of Agriculture and Food Systems. “We need to optimise the productivity of livestock systems, especially in those parts of the world that are able to produce meat with lower emission intensity than others,” he argues.
Animal farming supports the livelihoods of many people, particularly in LMICs where there are limited economic alternatives. Sustainable intensification of livestock systems in these countries could tackle both food security and conservation objectives.
“The carbon footprint for livestock production varies a lot,” says Dr Rafael De Oliveira Silva, Chancellor’s Fellow in the Global Academy of Agriculture and Food Systems. “It could be zero or even negative if you consider carbon sequestration, but if it is associated with deforestation, it can be over 100 kilograms of carbon dioxide equivalent per kilogram of meat.”
By using innovative bio-economic models, Dr De Oliveira Silva and Moran, can analyse the impact of changes to land use, land management and the demand for meat, as well as the adoption of new technologies, on the greenhouse gas emissions of beef production.
Spotlight on Brazil
In 2020, Brazil was the world’s largest exporter of beef, providing close to 20 per cent of total global beef exports. It is also the most biodiverse country in the world, and the most forested, holding about 60 per cent of the Amazon rainforest.
As beef production grows so does the need for pastures, which is a major driver of deforestation. Urgent measures are required if Brazil is to reconcile its international commitments to biodiversity conservation while also meeting the global demand for beef.
“Brazil has set itself very ambitious targets, committing to reduce greenhouse gas to 43 per cent below 2005 levels by 2030, mostly by ending Amazon deforestation,”Dr De Oliveira Silva explains.
He has been working with the Ministry for Agriculture in Brazil (MAPA) to help the Brazilian Government achieve the pledges it made at COP21 and the country’s Nationally Determined Contribution to the Paris Climate Agreement (2015). “We were contacted by the Ministry of Agriculture because they wanted to know how beef production systems would have to adapt to reconcile demand projections with deforestation targets.”
Dr De Oliveira Silva has developed bio-economic models that compare the cost-effectiveness of MAPA’s sustainable agricultural intensification (SAI) policies for livestock production. The aim of these policies is to reconcile a desire for increased productivity (output per hectare) while simultaneously reducing greenhouse gas emissions.
The effects of various greenhouse gas mitigation measures, including the use of feed supplements and nitrification inhibitors, were analysed in Cerrado, the central Brazilian savannah which supports more than 30 per cent of Brazil’s cattle herd. The results showed that pasture restoration by chemical and mechanical treatment of the soil to encourage the growth of grasses is by far the most effective measure for reducing emissions.
“Our analysis indicates that Brazil’s greenhouse gas emission targets can be achieved by restoring 15,000,000-20,000,000 hectares of degraded pastureland, representing approximately 10 per cent of Brazil’s pastureland,” Dr De Oliveira Silva says.
Restored pasturelands reduce greenhouse gas emissions by sequestering carbon into the soil and increasing the efficiency of cattle feed production, which leads to cost savings in beef production. Further reductions in greenhouse gas emissions are achieved by avoiding the need to clear additional forest areas for grazing.
To drive pasture restoration, MAPA’s Low Carbon Agriculture programme has been providing financial incentives for farmers since 2010. Dr De Oliveira Silva’s work demonstrates the effectiveness of the scheme and supports investing in a second phase between 2020 and 2030.
“After a slow start, the Low Carbon Agriculture programme has gained traction and today lots of farmers are adopting measures to restore pastures in Brazil,” he says.
In addition to informing government policies, Dr De Oliveira Silva is working with the Brazilian company JBS, one of the largest meat processing companies in the world, to devise a greenhouse gas emissions reduction plan to achieve net-zero by 2040. “We are helping JBS to identify measures to not just reduce carbon dioxide, but methane emissions as well.”
On a 100-year timescale, methane’s global warming potential is more than 28 times that of carbon dioxide. In recognition of the need to take global action on methane, at COP26 in 2021, more than 100 countries (including Brazil) pledged to cut methane emissions by 30 per cent by 2030.
“Reducing methane emissions is more complicated than reducing carbon dioxide emissions, because it requires different, more expensive technologies,” explains Dr De Oliveira Silva.
Selective breeding, feed supplements and some promising additives can help cattle use feed more efficiently and reduce their methane production, but these approaches are yet to be widely adopted.
While most models for calculating the environmental impact of meat production provide a fixed number, the model developed by Dr De Oliveira Silva can capture the effects of changes in demand.
“Demand is the main driver of technology adoption,” Dr De Oliveira Silva says.
In Brazil, if the demand for beef increases, farmers have to intensify production in the context of deforestation-control policies, which stimulate the adoption of pasture restoration measures resulting in reduced greenhouse gas emissions. Conversely, and counter-intuitively, reduced demand for beef could lead to an increase in emissions due to reduced incentives to restore pastures.
Applying these models to other beef production systems around the world could shed light on how to mitigate the environmental impact of production and still meet demand. Professor Moran has recently embarked on a BBSRC-funded project Transforming the Debate about livestock systems transformation, that will examine the future of the UK’s livestock sector taking into consideration changes in consumer preferences and emerging technologies, such as genetics and breeding techniques. This has the potential to markedly reduce greenhouse gas emissions.
“We look forward to supporting informed dialogues among sector stakeholders, including scientists, farmers, processors, retailers, consumers, investors and policy makers, and will seek to find consensus on how livestock production systems will need to change to meet the UK’s net-zero targets,” says Professor Moran.