A global switch to sustainable diets is essential for addressing the climate crisis, according to the Intergovernmental Panel on Climate Change (IPCC). The panel highlighted this important climate change mitigation measure and several others in its latest report, released in March, 2023. However, power exercised by non-scientists during the review process significantly hampered the strength of this recommendation.
The IPCC chair, Hoesung Lee, warned during a press conference for the report’s launch that “we are walking when we should be sprinting” on climate action. The synthesis report showed what impact this slow pace of action is having, including threatening food systems around the world. As the report made clear, communities in the Global South are primarily facing the “largest adverse impacts” to their food and water security from extreme weather and climate events.
The emissions from meat-heavy, unsustainable diets—such as those typical in wealthier, industrialized nations of the Global North, such as the US and the EU member states—contribute to these Southern communities’ climate crisis-related vulnerabilities. Instead of exercising power to control the narrative, true dietary change in wealthier, industrialized countries would increase the chance for all people to have adequate and healthy diets within a climate mitigation future.
The synthesis report and plant-based diets
The synthesis report is the final offering in the IPCC’s sixth assessment cycle. During this cycle, the panel has produced six reports on the climate crisis. In the synthesis report, the IPCC has effectively distilled all its findings from those other dispatches into one.
Lee described the report as the “fundamental policy document for shaping climate action in the remainder of this pivotal decade.”
Unsurprisingly, energy system transformation features heavily in the IPCC’s to-do list for climate action. In particular, it pointed to the importance of increasing the capacity of alternatives to fossil fuels, such as wind and solar power. The panel also detailed various ways to increase energy efficiency in transport, industry, and home energy usage.
Additionally, the panel highlighted several measures related to agriculture and food systems. Among these, the IPCC report noted that a shift to “balanced and sustainable healthy diets” presents an “important” opportunity for climate action. A footnote in the report provided more detail on such diets, explaining that they “feature plant-based foods” and “animal-source foods produced in resilient, sustainable, and low-GHG emissions systems.”
As the climate newsletter Distilled reported, in their reports during the sixth assessment cycle, IPCC scientists also intended to specifically emphasize the importance of dietary change—from animal-based foods to plant-based foods—among certain populations.
The newsletter explained that a leaked draft of a mitigation-focused report in the cycle showed that its scientific authors planned to recommend a shift to diets “with a higher share of plant-based protein in regions with excess consumption of calories and animal-source food,” due to the high climate costs of the “average emission-intensive Western diet”.
As the scientists’ planned recommendation indicates, consumption of animal-based foods is not spread equally around the world. Typically, people in industrialized Western nations consume more meat and dairy than elsewhere. According to Our World in Data, the top three countries for per capita meat consumption in 2020 were the US, Portugal, and Spain. Meanwhile, Montenegro, Albania, and Switzerland, had the highest per capita milk consumption that same year.
However, the IPCC scientists’ assertion about Western diets was nowhere to be found in the final version of the mitigation report or, ultimately, the synthesis report. This is because non-scientist country delegates review the IPCC reports prior to publication and can suggest changes. Distilled highlighted that during the review part of the process for the mitigation report, delegates from major meat-producing countries “lobbied significantly” against its inclusion.
Country delegates also successfully lobbied to curb scientists’ desire to identify the “environmental costs of meat”, the newsletter said. For instance, Greenpeace Unearthed highlighted that Argentina requested deletions related to meat’s climate costs. It argued that “not all meat production systems play a detrimental role in terms of GHG emissions,” pushing against the inclusion of generalizations that would suggest otherwise.
Unearthed reviewed a leak of thousands of comments from delegates and others on the draft mitigation report. It reported that, alongside lobbying by major animal feed and beef producer nations, the IPCC also faced pressure from big fossil fuel-producing countries to water down aspects of the report. These efforts included pressing the panel to “remove or weaken a key conclusion that the world needs to rapidly phase out fossil fuels”, according to Unearthed.
The climate cost of animal-based foods
Despite country delegates’ efforts to render the climate costs of animal-based foods near invisible in the IPCC report, studies elsewhere have made them abundantly clear.
For instance, a 2021 study compared the greenhouse gas (GHG) emissions of animal-based and plant-based foods. The findings, published in the journal Nature, indicated that, on average, the emissions of animal-based foods are approximately double those of plant-based foods. The researchers included GHG emissions from the production of feed for farmed animals in their calculations.
A prior study from 2018 also investigated the GHGs associated with the production of different foods. This analysis was based on data from over 38,000 commercial farms across 119 countries. It too found that animal-based foods are emissions-intensive, particularly beef, lamb, and cheese. Critically, it stressed that even the “impacts of the lowest-impact animal products typically exceed those of vegetable substitutes, providing new evidence for the importance of dietary change.”
Meanwhile, an infographic included in the IPCC’s climate change and land report provided a clear picture of how dietary change serves as climate action. It pointed to the mitigation potential of various diets. In this context, mitigation refers to each diet’s capacity to reduce emissions. It showed that consuming only plant-based foods had close to double the GHG mitigation potential of a “healthy diet”, meaning one that included levels of meat and sugar in line with “global dietary guidelines.”
Least responsible, most affected
Emissions-intensive Western diets are contributing to the climate crisis, which is impacting poorer countries hardest.Aditi Mukherji, one of the authors of the Synthesis report, has stressed that these countries “have contributed least to climate change.”
Climate change is a threat to food systems in these regions. The IPCC report noted [p5] that “weather and climate extreme events have exposed millions of people to acute food insecurity and reduced water security.” The report pointed to Central and South America, Africa, and Asia, as among the regions hardest hit. It said that these regions, alongside the least developed countries, small islands, and the Arctic, as well as Indigenous Peoples, low-income households, and small-scale food producers, face “the largest adverse impacts.”
Leonida Odongo, from the Kenyan social justice organization Haki Nawiri Afrika, says that the climate crisis is having a “devastating impact” in Africa, for instance. She points to Cyclone Freddy as a recent example. This cyclone hit Malawi, Mozambique, and Madagascar in February and March, 2023. It has impacted over two million people, displacing more than 650,000 with heavy rain and flash floods that washed away homes and roadways and damaged power grids. The cyclone’s appearance also coincided with a cholera outbreak in Malawi and Mozambique, worsening the spread of the disease and complicating recovery efforts. By damaging both subsistence and commercial farms and destroying the infrastructure that brings food products to market, the cyclone has also caused significant disruption to food production and food access in these three countries, where 70–80% of people obtain their living from agriculture.
Closer to home, Odongo says that a years-long drought has destroyed many Kenyan farmers’ livelihoods, with their crops “wilted on the farms”. Moreover, the droughts have sparked conflicts between crop farmers and those who raise animals, due to a scarcity of land and water resources. Odongo explains that “with increasing climate change manifested through erratic rainfall, droughts, and flood, many households are losing their sources of livelihoods, some lose their herds of cattle, and in some instances, lives are lost.” The list of climate change impacts is long, and often disproportionately harms women.
Odongo stresses that Kenya “is an agricultural country,” with around 33% of its GDP linked to the sector. For comparison, agriculture and other food-related sectors contributed approximately 5% to the US’ GDP in 2021. Meanwhile, tourism is another significant contributor to Kenya’s economy. In 2019, before the coronavirus pandemic shut down tourism around the world, the total impact of this sector on the country’s GDP was around 10%. Tourism in the country is reliant on the presence of wildlife. But as Odongo says, wild animals are not exempt from climate crisis-related suffering and they can “face death due to prolonged drought.”
Diet-change could contribute a great deal to emissions cuts
The US bears a historic and enduring responsibility for the climate crisis, having contributed around 20% of global emissions since 1850, according to Carbon Brief. Going further back in time to 1750, points to Europe, particularly countries in the European Union (plus the United Kingdom), as the most significant contributor to global emissions through time.
In these wealthier countries, many people consume the emissions-intensive Western diet that the IPCC scientists referred to. Therefore, a switch to healthier and more sustainable diets in such nations “can contribute a great deal to mitigating climate impacts,” according to Timothy A. Wise, senior advisor at the Institute for Agriculture and Trade Policy (IATP).
In particular, Wise says that “the way we produce and consume factory-farmed meat has to change.” The author of Eating Tomorrow: Agribusiness, Family Farmers, and the Battle for the Future of Food, adds that, although changing consumer behavior toward more plant-based consumption is important for limiting the climate impacts of food production, “it may be more important for governments to shift incentives that [currently] allow factory farms to sell meat at prices that fail to account for the true social and environmental costs of production.”
The scaling down of industrial animal agriculture holds the potential to meaningfully reduce greenhouse gas emissions in the near-term. This is because one of the key gases the industry emits is methane. As IATP has highlighted, animal-based industrial farming contributes around 33% of agriculture’s overall methane emissions in the US.
Methane accounts for 17.3 percent of global greenhouse gas emissions, second only to carbon dioxide. It is a short-lived but potent greenhouse gas, 27 times more powerful than CO2 at warming the atmosphere. As the World Resources Institute has explained, because “it exists for a relatively short time in the atmosphere, cutting methane provides a quick benefit in terms of limiting near-term temperature rise.”
A report by ClimateWorks Foundation and the Methane Hub, released in April, also pointed out that “reducing methane can have many additional benefits beyond emissions reductions, including reduced air pollution, greater land conservation, and water preservation.”
Industrial agriculture negatively impacts farmed and wild animals
Dietary change in wealthier countries—away from animal products and foods produced through industrial agriculture—would be transformative both for climate change mitigation and for reducing the suffering of farmed animals. As veterinarian Jean-Jacques Kona-Boun highlighted in a 2020 paper, industrial agriculture causes animal suffering “throughout all stages of production—breeding, housing, transport, usage and slaughter.”
The paper pointed to both physical and emotional suffering of farmed animals within industrial meat production. Some of this is due to “conscious and deliberate acts of cruelty,” Kona-Boun said. But much of the suffering involved is not due to “malicious acts but simply by standard industry practices.
Many farmed animals are routinely subjected to mutilation, such as removal of their teeth, tails, beaks, and testicles, including confinement of female pigs in gestation crates and egg-laying chickens in battery cages. Wild animals are also industrially farmed for fur and other wildlife-derived products, suffering in similar ways.
More broadly, the global food system—especially industrialized food production—causes immense harm to wild animals and biodiversity through changing patterns of land use and worsening climate change. As a 2021 Chatham House report supported by the UN Environment Programme and Compassion in World Farming highlighted, agriculture is the leading driver of global biodiversity loss.
This is in part due to industrial production converting forested lands for agriculture, which destroys plant biodiversity and leaves wild animals without habitat and food, while accelerating climate change. Land conversion often has negative impacts for farmed animals, wild animals, and the global environment. Prominent examples include large-scale deforestation across the Amazon for cattle ranching and cattle feed production and in Brazil’s Cerrado savannah biome for cattle ranching.
As Tom Philpott, research associate at the John Hopkins Center for a Liveable Future, explained in a Mongabay podcast, industrial agriculture is also causing severe ecological degradation in the two mainstay areas of US food production: California and the Midwest Corn Belt.
Philpott said that the industry is engaged in a “race to the bottom” of the groundwater in California, a major national and international dairy, fruit, and vegetable production region, due to overuse of scarce local water resources. Meanwhile, commodity crop producers in the Midwest are engaged in a similar race “to the bottom of the soil profile”, having heavily depleted local topsoil, he said. Industrial agricultural producers in these places are “undermining the very ecological assets that prop them up.”
Part of the ecological damage in these areas is due the extensive use of artificial inputs, such as fertilizers, pesticides, and antibiotics in the case of farmed animals. Industrial arable and animal farming are both heavily reliant on such inputs, which can cause widespread pollution of the environment and threaten the health of people, other animals, and ecosystems overall.
Learning from the global South
Dietary change can help to limit agriculture’s damage to wildlife and ecosystems, as the IPCC relayed in its synthesis report. The report explained that dietary change, as well as reductions in food waste and loss, offer “important opportunities for [climate] adaptation and mitigation while generating significant co-benefits in terms of biodiversity and human health.”
As the nonprofit A Growing Culture’s Josh To points out, however, exactly how dietary change happens is critical. To argues that switching from eating animals raised in industrial conditions to vegetables grown using industrial practices will not eliminate “ecosystemic chaos” and climate harms.
IATP’s Wise believes that wealthier countries can look to the Global South for guidance on the best direction of change. The practices of smallholder farmers there show that “in diversity, there is strength,” he says. He is referring to farming that aims to produce multiple foodstuffs in the same system, such as a variety of different crops. This stands in contrast to industrial practices that tend to focus on maximizing yields of the same foodstuff, like monocropping.
Odongo too says that there are “good things happening in the [African] continent,” although these are rarely celebrated or acknowledged in the West. She suggests that the development of platforms for information-sharing and cross-learning would be beneficial to all involved.
Wise points to communities in southern Africa that have traditionally used agroecological practices. These practices provided communities with the most resilience as it “gave them protection against weather shocks while providing diverse and healthy diets at low cost,” he says.
Odongo describes agroecological farming as a form of agricultural production that “protects the environment, respects local knowledge, and protects biodiversity”. Similarly, the Ecological Society of America describes the discipline as one that “considers the needs of human society, wildlife, and natural resources within an agricultural system.”
In other words, the farming principles of agroecology produce food by working with natural ecological processes, rather than controlling them or replacing them with artificial inputs. The approach also differs from conventional industrial agriculture because it embraces diversity and local ecological knowledge, recognizing that different ecosystems have varying capabilities to be productive.
In the Mongabay podcast and his most recent book, Perilous Bounty: The Looming Collapse of American Farming and How We Can Prevent It, Philpott also highlighted how the US could benefit from shifting to agroecological practices.
Wise argues that the “incessant alarms” Northern policymakers sound about “feeding the world” serve to “justify their policies to industrialize food systems in places like Sub-Saharan Africa,” but often fail “on their own terms.” Instead, he calls for curtailing the expansion of industrial animal agriculture and reducing its “alarming share” of food waste as a few ways to simultaneously reduce harm to farmed animals and slow the speed of climate change.
The IPCC’s Sixth Assessment Report shows that communities in the Global South need climate action—not rhetoric and politics—from wealthier countries that lead in both emissions and per capita meat consumption. High-emitting nations must reduce their greenhouse gas emissions, including those from food systems, quickly and in earnest, to limit the global climate crisis and increase food access for the world’s most vulnerable.
IPCC’s analysis shows that in wealthier countries, dietary change away from animal products, supported by inclusive food system transformation away from industrial production, can meaningfully contribute to reducing global GHG emissions. Changes to food production and consumption can also help to address the biodiversity crisis and reduce the suffering of farmed animals in the industrial food system.
Despite the action of vested interests to silence IPCC’s most recent endorsement of diet change as an important climate change mitigation strategy, embracing the necessity of reducing animal farming and reshaping the diets of the wealthiest nations remains one of the clearest paths toward climate mitigation for the good of animals, people, and the environment.
 Natalia Vega Mejía et al., “Implications of the Western Diet for Agricultural Production, Health and Climate Change,” Frontiers in Sustainable Food Systems 2 (2018), https://www.frontiersin.org/articles/10.3389/fsufs.2018.00088.
 Xiaoming Xu et al., “Global Greenhouse Gas Emissions from Animal-Based Foods Are Twice Those of Plant-Based Foods,” Nature Food 2, no. 9 (September 2021): 724–32, https://doi.org/10.1038/s43016-021-00358-x.
 Elizabeth M. Allen, Leso Munala, and Julie R. Henderson, “Kenyan Women Bearing the Cost of Climate Change,” International Journal of Environmental Research and Public Health 18, no. 23 (December 2, 2021): 12697, https://doi.org/10.3390/ijerph182312697.