What does the global shift in diets mean for climate change?

To limit global warming while feeding an expanding population, every part of the food system from farming to refrigeration will likely need to become cleaner and more efficient.

At the same time, there is growing recognition of the important role people’s diets will need to play in achieving international climate targets.

The food people eat is heavily influenced by culture, geography and wealth, but governments can also play a key role in influencing dietary change, through everything from farming subsidies to healthy eating guidelines.

In this Q&A, Carbon Brief examines how diets are already changing and what will be required to ensure the world’s food consumption is “climate-friendly”.

What is a ‘climate-friendly’ diet?

There has been extensive discussion of what constitutes a “climate-friendly” diet. While there is no universally accepted answer and no internationally agreed guidelines, the scientific consensus has converged on a handful of key features.

Chief among these is the importance of keeping animal products – particularly red meat, such as beef, and dairy – to a minimum.

Nevertheless, the impact of meat and dairy on the climate is a complex and contentious issue, which is explored in far greater depth in Carbon Brief’s interactive explainer.

Food and climate

This article is part of a week-long special series on how food production, consumption and waste are helping to drive climate change

Other elements of climate-friendly diets are a diverse array of minimally processed grains, tubers, fruits and vegetables, preferably varieties that are less likely to spoil and do not rely on energy-intensive transport, such as planes. (Although food transport is a relatively small consideration for overall emissions.)

This article will focus primarily on the consumption of red meat and dairy products, as these have been the main focus of efforts to curb dietary emissions.

It will also mainly address greenhouse gas emissions from food, while recognising that there are several – often, but not always aligned – issues at play when optimising diets, including health, adequate nutrition and other environmental impacts.

Why do people’s diets need to change?

Concerns about the impact of meat and dairy consumption on the climate and the wider environment are not new.

However, over the past decade there has been a growing focus on sustainable diets that can feed the millions of people around the world who are malnourished or obese, while remaining within planetary limits.

A paper published in 2007 stated that the emissions from meat “warrant the same scrutiny as do those from driving and flying”. Two years later, the influential British economist Lord Stern suggested eating meat would, ultimately, become as unacceptable as drink driving.

Nevertheless, so far diets have not been subject to the kind of political attention that has driven action to decarbonise other high-emitting sectors.

The launch of the IPCC’s special report on climate change and land in 2019 made it clear the goals of the Paris Agreement require a focus on food systems, with much of the resulting news coverage focusing on the scientists’ references to dietary change.

Dr Hans-Otto Pörtner, a co-chair of one of the IPCC’s working groups, said at the time they “don’t want to tell people what to eat…But it would indeed be beneficial, for both climate and human health, if people in many rich countries consumed less meat, and if politics would create appropriate incentives to that effect.”

However, as a recent letter by a group of medical professionals to the Lancet points out, dietary change has been relatively “neglected” in international climate politics.

A recent report produced by a group of organisations including the UN Environment Programme (UNEP) confirmed that no national climate plans explicitly discuss sustainable diets.

It concluded that adding diets and food waste to NDCs could set a course for cutting emissions by an extra 12.5bn tonnes of CO2 equivalent (GtCO2e) each year, 20% of the reductions needed to deliver on the Paris Agreement’s 1.5C target by 2050.

Meanwhile, without wealthier countries curtailing their consumption of red meat and dairy products, in particular, it is likely they will exceed regional targets and make the Paris Agreement targets of 1.5C or “well below” 2C warming harder to reach.

One study found that at current rates of emissions growth from the sector, livestock could take up 37% and 49% of the global emissions budget “allowable under the 2C and 1.5C target, respectively,” in 2030.

People denouncing the impact of industrial livestock on the planet at COP25. Credit: Marcos del Mazo / Alamy Stock Photo.

Failure to implement “animal to plant protein shifts” would make drastic changes from other sectors “far beyond what are planned or realistic” necessary, wrote Dr Helen Harwatt, an environmental social scientist at Harvard Law School.

One reason for this is that dietary change not only reduces emissions directly, but also means more land is made available as livestock pasture is freed up.

In many future scenarios, this sparing of land makes space for the mass rollout of bioenergy with carbon capture and storage (BECCS) and afforestation projects. Dietary changes could mean there is less risk to food security as these projects compete with agriculture.

Doelman describes such changes as a “win-win” as there is also less risk that emissions from food production will be outsourced to other countries:

Dr Paul Behrens, a researcher who focuses on the environmental impact of human consumption at Leiden University, tells Carbon Brief that dietary change also has many extra benefits:

The release of the EAT-Lancet planetary health diet in 2019 – described as the “first attempt to set universal scientific targets for the food system” – marked a “watershed” moment, with a call for a reduction of more than 50% in global meat consumption.

The study, produced by 37 scientists, provoked concerns from the food and agriculture industry, and a statement from the Italian government said its recommendations could “end up being nutritionally deficient and even dangerous”.

But the report’s authors are clear that in their view reaching the Paris Agreement targets is “not possible” by just decarbonising the global energy system, stating:

Are people in high-income nations eating more climate-friendly diets?

Globally, there is no doubt the consumption of high-emissions food products has increased substantially in recent decades.

What is more, analysis conducted by Chatham House shortly before the Paris Agreement in 2015 found that in Brazil, China, the UK and the US, public understanding of the link between diet and climate change was “very low”.

Despite this, there are suggestions that high-income nations, particularly in Europe, have started shifting towards more plant-based diets.

Quinoa salad bowl in healthy vegan restaurant. Vienna, Austria. Credit: Glenstar / Alamy Stock Photo.

This apparent trend has seen the French president backing a citizens’ call for a 20% reduction in meat and dairy consumption, as well as Germany described in a report by the US Department of Agriculture as leading a “vegalution” – vegan revolution – in Europe.

The growth in vegetarian eateries and plant-based alternatives appears to be matched by the public’s eagerness, with 63% of Germans, 51% of Canadians and 50% of British people trying or willing to reduce their meat consumption, according to various surveys.

However, Laura Wellesley from Chatham House says that while the landscape has changed since she started working on this topic before COP21 in Paris, the extent to which behavioural changes are actually taking place is “still unclear”.

The chart below shows how per-capita meat consumption is changing across Europe, based on food balance sheet data from the FAO. Contrary to the idea of a shift to plant-based foods, overall meat consumption has seen a general increase, although most nations have experienced declines in red meat intake.

Changes in per-capita consumption in a selection of European countries of red meat (red), specifically beef, mutton and goat, over time, as well as pork (dark blue) and poultry (light blue), in grammes per day. The data is an overestimation of actual consumption as it is derived from per capita “food supply”, which does not account for food waste at the consumer level. The FAO updated its methodology for calculating food supplies in 2014, which it says may result in some discrepancies with previous data. Source: FAO. Chart by Carbon Brief using Highcharts.

Overall per-capita meat consumption is roughly twice the global average in Europe and dairy consumption is around three times higher, according to FAO data. Meat consumption in Australia and the US is even higher.

According to Benton, a key driver behind the decline in consumption of beef and lamb in some “western” countries is “red meat is bad” public health messaging that stretches back to the 1970s.

Meanwhile, high levels of meat consumption in nations such as Spain and Austria have been attributed in part to subsidised animal farming that results in cheap, easily available products.

Eastern European countries, including Romania and Bulgaria, see lower overall meat consumption, which can be linked to lower average incomes.

Dr Marco Springmann, a population health scientist at the Oxford Martin Programme on the Future of Food tells Carbon Brief that, while some wealthier nations have shown a drop in per-capita red meat and dairy consumption, it is generally coming from a very high level.

The notion of a recent shift to vegetarianism and veganism is largely based on a combination of national diet data, consumer surveys and industry and retailer reports on plant-based foods.

However, Springmann says national dietary surveys have “huge problems”. Specifically, they are often based on self-reporting and there is evidence people in high-income nations under-report consumption, particularly for products they feel they should not be eating.

The UK government’s “family food” survey even includes the disclaimer: “It is a widely recognised characteristic of self-reported diary surveys…that survey respondents tend to under-report”.

“If people really ate only what is reported in the national dietary survey of the UK, everybody would be underweight by quite a bit,” says Springmann.

Meanwhile, the global “alternative meat” market was worth $14bn last year, according to research by Barclays, with particular interest among young people for dairy- and meat-free options.

This is just 1% of the global meat industry, although the same research predicted this could rise to 10% by 2029.

However, there is scepticism among experts. Wellesley tells Carbon Brief that in the UK the optimism of the “Greggs vegan sausage roll moment” should be treated with “a degree of caution”:

As the charts above indicate, declines in red meat tend to be made up for by an increase in pork and particularly poultry consumption.

While emissions from these products are far lower per gramme than red meat, there are concerns about some of the knock-on effects of their increased consumption, particularly due to their reliance on soy as an animal feed.

Soy production is a major contributor to deforestation in South America. Pig and poultry farming in the UK consume 29% and 53%, respectively, of the solid “cake” derived from soy which is used to feed animals and, to a much lesser extent, humans.

Separately, a report by the European Environment Agency found that, while the EU had seen a 14% overall decline in per-capita beef consumption from 2000-2013, the environmental benefits were “somewhat offset” by a 15% increase in consumption of cheese, another product that comes with a considerable emissions footprint.

While red meat is still widely recognised as having the largest climate impact, some scientists and NGOs have emphasised the need to address all animal products when targeting more climate-friendly diets.

“My personal viewpoint…is that what you really need to be doing is cutting your consumption across the board, of all kinds of animal products,” Dr Tara Garnett, leader of the Food Climate Research Network tells Carbon Brief.

How are diets changing around the world?

Garnett tells Carbon Brief that, in her view, globally, there is increasing awareness of the impact that land-use change, deforestation and livestock methane is having on the climate.

However, she notes that outside of “northern” nations, an appreciation of the role people’s individual diets play in driving climate change is “less clear” to her.

Dr James Bentham of the University of Kent, who recently published a study based on FAO data examining worldwide dietary trends, tells Carbon Brief there has been a “global convergence” in diets.

As people in western European nations, alongside countries such as the US, eat less red meat and dairy, inhabitants of emerging economies in Asia and South America tend to eat more of these products than they did in recent decades.

This trend can be seen in the chart below, based on FAO data for meat, with nations such as Brazil showing a significant increase in per-capita consumption while the US and Australia remain fairly steady.

Changes in per capita consumption in various nations of red meat (red), specifically beef, mutton and goat, over time, as well as pork (dark blue) and poultry (light blue), in grammes per day. The data is an overestimation of actual consumption as it is derived from per capita “food supply”, which does not account for food waste at the consumer level. The FAO updated its methodology for calculating food supplies in 2014, which it says may result in some discrepancies with previous data. Source: FAO. Chart by Carbon Brief using Highcharts.

Meat and dairy consumption have been considerably higher in Latin America than Africa and Asia for some time, with beef widely seen as a staple for the poor as well as the rich due to comparatively low production costs.

In Brazil, where the beef industry has a particularly high environmental impact and farming is the largest cause of national emissions, one study described discussions in the country of the diet-climate link as “marginal”.

Meanwhile, for many people eating large amounts of meat is still not an option, as evidenced by the fairly low rates of consumption in African countries. However, growing populations alone are still expected to result in nations such as Kenya and Nigeria significantly increasing their demand in the coming decades, even if per-capita intake remains low.

Researchers have noted that, when it comes to diets, there is no “one-size-fits-all” approach, arguing that many poorer nations will likely need to increase their dietary emissions to ensure their populations are eating healthily.

One recent study found that in 36 countries, home to around 2.5 billion people, the adoption of EAT-Lancet’s “planetary health” diet would increase agricultural emissions per capita by over 10%.

Dairy plays a big role in this, as it is both emissions-intensive and also recognised as important for preventing stunted growth in children.

In a relationship that has been dubbed “Bennet’s law”, when people become wealthier their rising incomes tend to correlate well with rising meat and dairy consumption. Benton tells Carbon Brief:

Benton agrees this trend is not “set in stone”, pointing to the example of India as a nation that, for various cultural, religious and economic reasons, has retained low levels of meat consumption. (It is, however, the world’s largest milk producer and its livestock sector is responsible for more emissions than road transport.)

A family eating vegetarian street food in Bodh Gaya, India. Credit: Eye Ubiquitous / Alamy Stock Photo.

Devinder Sharma, a food and trade policy analyst, says that, while India is “blessed” with a largely plant-based food tradition, he attributes rising emissions from emerging economies to the imitation of both western diets and industrial farming practices. “The problem is mostly coming from western countries,” Sharma says.

“Gradually people are realising that a reduction in meat consumption is what is ideal for the world to survive…but that realisation is very slow,” he tells Carbon Brief.

Ultimately, the relatively small changes in western diets will likely not be sufficient from a climate perspective, especially if other nations continue increasing their consumption of meat.

This is, perhaps, especially true for China, where supporting meat production has been government policy in recent decades and almost a third of the world’s meat is consumed. Much of the growth in global beef consumption has been driven by China.

Total consumption of red meat (beef, mutton and goat) in key economies, millions of tonnes, based on food supply data. The data is an overestimation of actual consumption as it is derived from per capita “food supply”, which does not account for food waste at the consumer level. The FAO updated its methodology for calculating food supplies in 2014, which it says may result in some discrepancies with previous data. Source: FAO. Chart by Carbon Brief using Highcharts.

In 2016, some English-speaking media reported that the Chinese government’s new dietary guidelines aimed to reduce meat intake by half, in a move backed by celebrities and welcomed by campaigners.

However, Li Shuo from Greenpeace East Asia tells Carbon Brief that much of the hype is “unfortunately based on misleading interpretation of the policy”. He adds: “I did not observe any change that the guidelines created for the dinner table.”

When will the world reach ‘peak meat’?

Amid discussions around diets and climate change, the concept of “peak meat” has emerged, with speculation around when the world will arrive at such a point.

In a letter to Lancet Planetary Health last year, scientists called for governments to “declare a timeframe for peak livestock” and incorporate this into their updated nationally determined contributions (NDCs) to the Paris Agreement.

They argue that, in wealthier nations, cutting demand for livestock products and not simply outsourcing production to other countries will be essential to create “Paris-compliant agriculture sectors”.

There is evidence that peak meat may be close. FAO forecasts suggest that in an unprecedented trend, after falling last year, meat production is once again on track to drop in 2020. Meat consumption per capita is projected to fall by nearly 3%.

While red meat production is set to decline slightly, with a 0.8% drop in beef, the main driver of this change is falling pork production, as the chart below indicates.

Trends in global meat production, millions of tonnes, including FAO projections for 2019 and 2020 indicated by the shaded grey area. “Red meat” includes beef, mutton and goat. Source: FAO. Chart by Carbon Brief using Highcharts.

However, this projected decline comes in unusual circumstances. Meat production has been hit twice this year, first by the outbreak of African swine fever which was already devastating pig farms in China and Vietnam and which has largely driven the fall in global pork output.

The other key event was the Covid-19 pandemic, which has disrupted all meat markets and supply chains due to labour shortages and facilities closing down temporarily.

The FAO did not specifically estimate the impact of coronavirus, but as the organisation’s chief economist Upali Galketi Aratchilage tells Carbon Brief:

Demand for meat has also dropped alongside production, as reduced sales in the food service industry due to Covid-19 closures have only been partially offset by increases in retail sales.

Prior to the pandemic production of beef (the meat with the largest environmental footprint) was already slowing down, even in nations such as the US and Brazil. On a per-capita basis, global beef consumption peaked in the 1970s.

A stall selling meat on the street in Hong Kong. Credit: Sergio Delle Vedove / Alamy Stock Photo.

While this seems like progress towards achieving overall peak meat, Aratchilage adds that prior to the pandemic they did not anticipate a global drop in demand for all meat products:

Dr Helen Harwatt, who led the call for “peak livestock”, tells Carbon Brief signs of changing consumer habits are promising, but would not be enough to bring about the changes required:

Can dietary guidelines help achieve climate targets?

Given the slow progress away from high-emitting foods, experts have concluded that interventions from official agencies and governments are likely to be necessary.

But despite the clear links between diets and climate change, fashioning policies in this area is still “politically toxic”, according to Simon Billing of the UK’s Eating Better, a coalition of civil society organisations.

This point is echoed by Jillian Semaan, who worked at the US Department of Agriculture during the Obama administration’s controversial attempts to encourage healthy eating in schools.

“Let’s be very honest, people do not like having their government tell them what to do,” she tells Carbon Brief:

Perhaps unsurprisingly, examples of targets being proposed by authorities to specifically reduce emissions from people’s diets are rare.

The EU’s recent “farm to fork” strategy indicated the importance of plant-based diets, but fell short of setting the targets proposed by NGOs.

In its guidance on achieving net-zero emissions by 2050, the UK government’s Committee on Climate Change (CCC) recommends reducing consumption of “the most carbon intensive foods” – beef, lamb and dairy products – by 20%.

The CCC says this recommendation is in line with recent dietary trends in the UK, with the committee’s land analyst Indra Thillainathan saying this was chosen over another scenario in which red meat and dairy consumption was cut by a more ambitious 50%. (However, the 50% target still appears as part of the CCC’s “further ambition” scenario.)

The chart below shows that the CCC’s recommendations do indeed appear to be in line with trends in UK diets, based on self-reported surveying by the government.

Recent trends in red meat, specifically lamb and beef, consumption (red) and dairy consumption (blue), with dotted lines indicating the 20% reduction target set by the Committee on Climate Change (CCC) and the 50% target which “may be needed, depending on progress in other sectors”. Source: Family Food statistics, CCC. Chart by Carbon Brief using Highcharts.

Despite this, the CCC says current downward trends “are not likely to be sufficient” to deliver the required changes.

The UK government has accepted the CCC’s net-zero target, but it has been more ambivalent about the dietary guidance. In one BBC News interview, former climate minister Claire Perry described telling people to eat less meat as “the worst sort of nanny state ever”.

This attitude is not unique to the UK, with authorities in other nations, including Germany and Ireland, showing hesitance in advising people to eat less carbon-intensive foods. Meanwhile, US vice president Mike Pence recently accused his Democrat opponents of trying to “cut America’s meat” as part of their proposals for tackling climate change.

Billing tells Carbon Brief this is is partly to do with the fact that awareness among the public of the need for dietary changes to achieve climate targets is still fairly low:

As of 2016, an FAO report found just four countries – Germany, Brazil, Sweden and Qatar – specifically referencing environmental concerns in their official dietary guidelines. Since then, more including Canada, Norway and Switzerland have joined the list.

Others, including the UK, France, the Netherlands and Estonia, had “quasi-official” guidelines produced by government-affiliated entities that mentioned the environment.

Meanwhile, attempts to incorporate such considerations into US and Australian guidelines have been shelved after opposition from the meat industry and farmers.

Instead, while dietary guidelines tend to vary depending on the culture they emerge from, health is generally seen as their priority. Fortunately, as Benton tells Carbon Brief:

The CCC’s Thillainathan notes that the UK government’s healthy eating guidance, the EatWell Guide, recommends a much higher level of reduction than the CCC’s guidance, calling for an 82% cut from current levels of beef and lamb consumption.

A recent study led by population health scientist Dr Marco Springmann, found that the global implementation of dietary guidelines would cut food-related emissions on average by 13% – equating to 550MtCO2e – across all 85 nations with such guidelines.

Adoption of World Health Organisation dietary recommendations would be associated with a similar reduction in emissions of 12% on average, the study found.

The impact that national guidelines could have on emissions, as well as the dominance of red meat and, to a lesser extent, dairy in the footprints of each nation, can be seen in the chart below. Ofte