A key subject of discussion at the Cop28 summit in the UAE will be agriculture and how its impact on climate change can be reduced.
There will be a day dedicated to the issue and the UN’s Food and Agriculture Organisation is set to outline what changes to food systems are needed.
Also, during the run-up to Cop28, which begins at the end of this month, campaign groups have called for food served at the event to be vegan, amid concerns over the carbon footprint of animal agriculture.
That food systems are coming under the spotlight is, perhaps, not surprising because, according to one study, the agri-food sector accounts for as much as 34 per cent of global greenhouse gas emissions.
This includes the effects of changes to land use – such as the felling of forests or the draining of wetlands so that ground can be used to rear animals or to grow crops such as soya for animal feed – and emissions from supply chains, including processing and packaging.
“Progress has always been slow on climate policy and that’s why often new angles are sought on how to solve it,” said Prof Niklas Hohne, managing director of the NewClimate Institute in Germany.
“Now the new angle is food production, which includes many things – deforestation, fossil fuels for fertiliser.”
With food consumption becoming more prominent in discussions about climate change, it will be “one of many issues” to be debated at Cop28, said Prof Hohne.
Calls to eat less meat and dairy
Some environmental organisations now urge people to consume less meat and dairy because of these foods’ higher carbon footprint.
While not calling on people to become vegan, the WWF, for example, suggests that consumers replace chicken with chickpeas, butternut squash, tofu or cashew nuts, or try black coffee (or coffee with a plant-based milk substitute) instead of with milk.
A 2021 study in the Nature Food journal calculated that animal-based foods accounted for 57 per cent of greenhouse gas emissions from food production – more than double the impact of the plant-based sector.
“From cows, methane is a major contributor to greenhouse gas emissions,” said Prof Henning Otte Hansen, senior adviser in the Department of Food and Resource Economics at the University of Copenhagen.
More than 150 million tonnes of methane – described as being about 28 times as potent as carbon dioxide in its climate change effects – are produced each year by the world’s approximately 1.5 billion cattle.
According to Prof Hansen, there is a sliding scale among animal products, with beef and lamb the most carbon intensive, then dairy, pork and poultry.
The numbers game
However, some analysts argue that improvements in productivity mean that carbon emissions per unit of certain animal products have fallen.
“The number of cows has decreased and milk yields have gone up,” Phil Garnsworthy, professor of dairy science at the University of Nottingham in the UK, said of the situation in his home country.
While methane is much more powerful as a greenhouse gas than carbon dioxide, Prof Garnsworthy said it remained in the atmosphere for a relatively short period of time. Nasa says this is between seven and 12 years, compared with hundreds of years for carbon dioxide.
“It’s a flat line if you keep the number of cows the same,” Prof Garnsworthy said. “Having said that, methane is very responsive – if you reduce the number of animals, methane drops quickly.”
Cows vary markedly in their methane generation – there is as much as a twofold difference between individuals – and with genetic factors playing an important role, a “lot of geneticists and breeding companies” are interested in producing animals that generate smaller quantities.
Particular feeds could also help to reduce emissions.
While beef is often seen as the most carbon-intensive type of meat, Prof Garnsworthy said that in the UK, for example, this meat had a “much lower” climate impact because the animals eat grass.
“If you’re growing beef on land that used to be forest, it does have an enormous carbon impact, especially if you’re feeding [cows] soya,” he said.
However, he added that much logging was driven by demand for wood rather than the need for land for agriculture.
Global appetites rising
According to Food and Agriculture Organisation figures published by OurWorldinData, annual global meat consumption in 1961 was less than 100 million tonnes.
By 2013, the figure was about 300 million tonnes, excluding eggs, and is forecast to be in the region of 450 million tonnes by 2050.
According to Andrew Knight, adjunct professor in the School of Environment and Science at Griffith University, Queensland, Australia, changing consumption patterns and moving to plant-based diets “is not something that can be avoided”.
“It’s the most important strategy for addressing the high levels of greenhouse gas emissions and the adverse impacts associated with the livestock sector.
“Even at the subsistence level, virtually every study has shown that every variation of an animal-produce-based diet produces more greenhouse gas emissions than almost every form of plant-based diet.”
Aside from meat consumption by humans, Prof Knight’s research indicates that about 9 per cent of the global greenhouse gas emissions from animal agriculture is accounted for by pet food.
He advises dog and cat owners to give their animals nutritionally sound vegan food, which is now widely available.
As debate continues, the ways to reduce the impact of animal agriculture – including moving away from eating meat – will probably spark many headlines at Cop28.
