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Intensive farming can reach net zero but the solution lies in reducing animal protein consumption

woman with short hair and glasses in front of a bookshelf
9 min read
AUTHOR: Sophie Kevany
cattle intensive farming

In the UK an estimated 70% of farm animals are now raised on intensive farms and about 99% in the US. They are known as much for depriving animals of space, sunlight and the ability to express natural behaviours, as they are for their efficiency – churning out high volumes of animal protein, especially pork and chicken, at knock down prices.

As temperatures rise and emissions from agriculture come under ever greater scrutiny, there is now a third thing intensive farms might be known for: getting to net zero. The idea is not impossible, experts say, but there are two key emission reduction challenges: feed and manure.

Feed because intensively reared livestock subsist on a mix of grains and soy, themselves intensively grown using fertilisers that commonly contain nitrogen. Once soils are saturated, excess nitrogen is released into the atmosphere as a powerful, but less headline grabbing greenhouse gas, nitrous oxide.

Other fertiliser problems include the emissions released during the making of it and, more recently, a range of cost and supply issues linked to Russia’s invasion of Ukraine and the impact of that on natural gas supplies, a key fertiliser ingredient.

Nor do feed’s problems stop at fertiliser. Brazilian soy, which is exported to intensive farms around the world, is a leading cause of deforestation. Grains are problematic too. Their supply has been disrupted by the same Russian invasion and their mass cultivation is linked to biodiversity loss and the use of huge tracts of land that, many argue, could better be reforested, rewilded or used to grow human foods.

“Globally, 40% of the cereals we grow, and 77% of the soy, is used to feed animals. In the EU according to the European Commission, almost two thirds, or 66% of the cereal crop is used for feed,” said Peter Stevenson, chief policy advisor for Compassion in World Farming (CIWF).

At the other end of the digestive system is the manure that billions of confined animals produce, the disposal of which is causing problems around Europe from Northern Ireland to Spain, and in the US.

“In April this year the US EPA released a report that shows methane emissions from large-scale confined pig farms that liquify their manure increasing by 44% between 1990 and 2010. If you have bio-digesters, you should be able to reduce those emissions substantially, but they are costly and there are other drawbacks,” Stevenson said.

Despite the difficulties, pig and poultry producers in Ireland and the UK believe net zero is on the horizon. In an email the British Poultry Council (BPC) said its “members are committed to … try and achieve NetZero by 2040.”

The challenge is not small. UK poultry producers are highly dependent on imported soy and total feed can account for up to 85% of the sector’s total emissions. The BPC said its efforts to get to net zero will involve “investment in research and development projects to strengthen regenerative farming practices, using renewable electricity across all facilities, reducing water use intensity, exploring alternative feed sources, and improving bird feed [to meat] conversion.

Asked how bird welfare will be affected by its emissions reduction plans, the BPC said, currently, higher welfare and net zero are “moving in different directions,” mainly because “systems perceived as ‘higher welfare’ are often more resource intensive” and produce less.

The Swedish intensive farm nearing net zero

The results of the BPC’s efforts are yet to be seen but in Sweden at least one intensive farmer is already on the road to net zero and better animal welfare. On his farm, which has 16-acres for the pigs and about 550 hectares for crops, Anders Gunnarsson is growing his own barley feed and using a biodigester to turn pig slurry into fertiliser and gas.  The gas is used to power the farm and, later this year, one of his tractors.

Gunnarsson fattens about 20,000 pigs a year in batches of 5,000. The pigs are intensively raised but, unlike most intensive operations, they have free access to an outdoor space. “The standard stocking density is about 1 square metre per pig in Sweden. If you include the outside space, my pigs have about 1.8 square metres of space,” said Gunnarsson.

Those efforts mean Gunnarsson’s farm is nearly halfway to net zero and, because they have more space, sunlight and air, his pigs avoid the pain of tail and teeth removal – a standard practice on intensive farms normally done without analgesics – and require fewer antibiotics.

One of the greatest risks to human health is the rise of antibiotic-resistant superbugs and their development has been linked to the livestock sector’s use of antibiotics, particularly on intensive farms where animals are crowded together.

Surprisingly, Gunnarsson’s meat is not much more expensive than the norm, costing, he said, just one Swedish krone (about £0.08) above the average per kilo price.

Intensive pig farming

In Ireland, where almost all pigs are intensively farmed, a net zero pork sector is seen as a coming reality by 2050. As on Gunnarsson’s farm, pig slurry will become high-quality fertiliser and feed emissions will be reduced using Irish grown, high-protein versions of rape seeds, peas, beans, plus food industry “co-products,” said Edgar Manzanilla, head of pig development at Teagasc, Ireland’s agricultural research agency. Examples of co-products include brewer’s grains and potato peels.

On the welfare side, Manzanilla added, “we probably will need more space for the pigs, or fewer pigs in the same space.”

Sows living in stable at an industrial animal farm

Intensively farmed pigs have their teeth clipped and tails docked without painkillers. They don’t have access to outdoor space and live in crammed cages where they struggle to move.

Cows in a dairy farm

Milking cows by automatic industrial milking rotary system. Milking rotary systems can milk around 400 cows, depending on the machine, in two hours. The cows are forced to stand up and cannot move. The machine can do 2-3 milking rounds per day.

Left: Intensively farmed pigs have their teeth clipped and tails docked without painkillers. They don’t have access to outdoor space and live in crammed cages where they struggle to move.

Right: Milking cows by automatic industrial milking rotary system. Milking rotary systems can milk around 400 cows, depending on the machine, in two hours. The cows are forced to stand up and cannot move. The machine can do 2-3 milking rounds per day.

Eamon Haughey, sustainable agriculture and land use lecturer at Ireland’s Atlantic Technological University and contributor to the United Nations IPCC Special Report on Climate Change and Land, said he too could see possibilities for net zero pork in Ireland.

“Pigs don’t produce much methane, compared to cattle, so if there was some tillage associated with the pig farm, and they can grow their own feed, and if they had some solar panels for electricity … that might be possible. Or if they had some forestry, that could all help to get to net zero, so it’s not impossible,” he said.

Challenges remain, however. “Pigs need a lot of antibiotics to prevent disease. Plus, there are a lot of potential water quality issues associated with intensive pig farms and the slurry they produce.” The other option to reduce emissions, he said, is “switching to a more plant-based diet is what the IPCC recommends.”

The problem with Brazil’s soy production

Nor is replacing soy quite that simple, said Joana Faggin, who previously worked with the Brazilian forestry service and is now a senior researcher with Dutch NGO, AidEnvironment.

“Growing feed [for pigs and chickens] locally would make it [net zero intensive farming] possible, but then I am not sure if large scale transition is possible by 2050,” she said. “It took 20 to 30 years for the soy supply chain to build up and that was market driven. Moving away from the existing global soy supply chain will take a lot of effort.”

Much of that effort may involve dealing with the likely higher costs of soy alternatives, particularly given that what happens in Brazil’s soy supply chain is often improperly accounted for, Faggin said.

“In Brazil’s Matopiba region, for example, local communities are removed from their land every week to make way for deforestation, then cattle and soy production. The cost of that is not factored into the price of soy because there is no official cost,” she said.

With soy grown in the Amazon region, there is no cost to the land grabbing. The land is not protected, it is considered public. And the way it works is that the land is first occupied by those who have the means to remove trees, which costs about US$270 per hectare. This is often followed by cattle occupation and then soy production as part of the land-grabbing cycle,” she said.

Another feed switch challenge, said Tara Garnett, will be finding land. Garnett is an Oxford University food systems analyst and director of TABLE, a food system discussion forum involving Oxford, the Netherland’s Wageningen University and Sweden’s University of Agricultural Sciences.

amazon rainforest deforestation

Amazon rainforest deforestation to make land for agriculture and cattle pasture.

intensive chicken farming

Intensive chicken farming.

Left: Amazon rainforest deforestation to make land for agriculture and cattle pasture.

Right: Intensive chicken farming.

“We urgently need to reduce reliance on Brazilian soy, but to what extent will local feed production be on land that could be used to feed people directly or be rewilded?” she asked.

She too highlighted animal welfare risks and suggested eating less meat. “If decarbonisation leads to further intensification in the pig and poultry sector, then what are the animal welfare implications and what is the risk of higher stocking densities? We need to be decarbonising in a way that is compatible with high welfare.”

“Ultimately, within the UK, we need to be reducing our consumption of animal products. This doesn’t mean we should eliminate them from our diet, but we should be less reliant on them, to reduce the impacts of animal production.”

Another argument is that focussing on one type of livestock farming method versus another is unhelpful. Asked about getting intensive systems to net zero, John Royle of the UK’s National Farmers’ Union (NFU) advised against pitting one system against another. Instead, he said, “each have their place,” and while carbon output per kilogram of meat “might be lower in intensive systems, most forage-based systems offer a range of additional biodiversity benefits” and reduce reliance on “purchased feed, cereals and soya.”  

CIWF’s Stevenson goes a step further suggesting a low-emissions agricultural future would be one that prioritises welfare to the point of producing less meat, eggs and dairy.

The result, he said, would be fewer animals with more space, no need for pig tail docking, pig teeth clipping, poultry beak trimming or cattle dehorning, plus reduced antibiotic usage, lower disease risks between animals and from animals to humans, manageable amounts of manure, less but better-quality meat and reduced feed production freeing up land for more regenerative agriculture. All of that, he said, “falls into place if you put animal welfare at the heart of animal protein production.”

Most immediately, said Eline Reintjes, policy officer at FAIRR, a $66 trillion investor network that raises awareness of environmental and other risks created by intensive animal agriculture, a map would be helpful. “At present, there is no central roadmap in place for agriculture to reach climate goals by 2030 or 2050,” she said. “It’s a huge challenge with no silver bullet, although scaling up alternative proteins can provide a lower risk alternative to intensive farming.”


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