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Distribution of carbon in potential vegetation in areas of present-day animal feed croplands and pastures combined for each 5 arcmin grid cell Colour corresponds to the product of land area presently under cultivation multiplied by the potential vegetation carbon density, minus the quantity presently stored in agricultural vegetation.
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Extensive land uses to meet dietary preferences incur a ‘carbon opportunity cost’ given the potential for carbon sequestration through ecosystem restoration. Here we map the magnitude of this opportunity, finding that shifts in global food production to plant-based diets by 2050 could lead to sequestration of 332–547 GtCO2, equivalent to 99–163% of...
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... In the event of a transition in global food production to plant-based diets, a net reduction in greenhouse gas emissions of between 332 and 547 GtCO 2 is projected to be observed by 2050. This figure represents a reduction in CO 2 emissions of between 99% and 163%, which is in line with the objective of limiting global warming to 1.5 • C [5]. What strategies might be employed to reverse the global warming trend? ...
Adopting sustainable food choices is crucial to mitigating the environmental impacts of food production. Insect-based foods offer a promising alternative with low resource requirements and reduced greenhouse gas emissions. This study examines the psychological factors influencing consumers' intentions to purchase insect-based foods using an extended protection motivation theory (PMT) model that includes disgust as a critical factor. Data from 233 Italian participants were analyzed through partial least squares structural equation modeling (PLS-SEM). Results indicate that perceived response efficacy-the belief in the environmental benefits of insect consumption-and self-efficacy-confidence in one's ability to incorporate insect-based foods-positively influence purchase intentions. However, strong aversions rooted in disgust and low intrinsic motivation present major barriers, highlighting cultural resistance to entomophagy in Western contexts. Extrinsic motivators such as social recognition, perceived costs, and perceived severity or vulnerability to environmental issues had no significant effect. The findings suggest that effective strategies should focus on reducing disgust and strengthening consumer confidence, emphasizing the environmental benefits to shift attitudes toward sustainable dietary choices.
... Nevertheless, negative effects on biodiversity and soils are widespread in heavily grazed regions ( 1 , 20 , 43 ). In addition, especially in some countries of the Global South, grazing areas are increasingly expanded into forestlands ( 44 ). ...
Animal-sourced foods (ASFs) are among the most contentious topics in the broader public debates about sustainable food systems, climate change, biodiversity loss, and healthy nutrition. This focus on ASFs is unsurprising, as their production and consumption directly relate to numerous key sustainability dimensions, both in positive and negative ways. In this article, we review global trends in ASF production and consumption. We also analyze how more sustainable patterns of ASF production and consumption could be achieved in different world regions and what role plant-based alternatives and other types of technical and social innovations could play.
... For present-day pastures in potential forest areas, we assumed mean vegetation stocks in present-day pastures of 6 ± 3 MgC ha −1 , consistent with literature estimates including the Erb et al. analysis (3,7) because potential biome areas are assumed to contain a heterogenous or patchwork mix of established pasture and forest within 5-arcminute grid cells. This is consistent with our assumptions that treat the tree-covered fraction of present-day 5-arcminute grid cells as nonpasture area. ...
... We defined "potential forest" areas in our analysis as any of eight potential forest biome types, as well as savanna areas of sufficiently carbon-dense vegetation, as a proxy for high potential tree cover (corresponding to potential carbon stocks ≥75 MgC ha −1 ) consistent with Hayek et al. (3). "Potential grasslands" were defined as potential biomes types of grassland, shrubland, or tundra, and savannas with comparatively less tree cover (potential carbon stocks < 75 MgC ha −1 ) to reflect sparse and open-canopy savannas with sufficient open space and available forages for ruminant grazing. ...
... Additionally, we added parametric estimates for carbon in coarse woody debris and leaf and fine woody litter, in potential forest areas, consistent with the "nonliving pools" scenario in supplemental methods in Hayek et al. and references therein (3,41,42). Carbon opportunity costs of pasturelands. Carbon opportunity costs of pasturelands were calculated on every grid cell on a per-hectare basis of both annual fluxes and stocks integrated over 75 y. ...
Pastures, on which ruminant livestock graze, occupy one third of the earth’s surface. Removing livestock from pastures can support climate change mitigation through carbon sequestration in regrowing vegetation and recovering soils, particularly in potentially forested areas. However, this would also decrease food and fiber production, generating a tradeoff with pasture productivity and the ruminant meat production pastures support. We evaluate the magnitude and distribution of this tradeoff globally, called the “carbon opportunity intensity” of pastures, at a 5-arcminute resolution. We find that removing beef–producing cattle from high–carbon intensity pastures could sequester 34 (22 to 43) GtC i.e. 125 (80 to 158) GtCO 2 into ecosystems, which is an amount greater than global fossil CO 2 emissions from 2021–2023. This would lead to only a minor loss of 13 (9 to 18)% of the global total beef production on pastures, predominantly within high- and upper-middle-income countries. If areas with low–carbon intensity pastures and less efficient beef production simultaneously intensified their beef production to 47% of OECD levels, this could fully counterbalance the global loss of beef production. The carbon opportunity intensity can inform policy approaches to restore ecosystems while minimizing food losses. Future work should aim to provide higher-resolution estimates for use at local and farm scales, and to incorporate a wider set of environmental indicators of outcomes beyond carbon.
... However, as van Zanten et al. discuss, livestock production from grasslands is not without environmental trade-offs either: (i) ruminants typically emit more CO2 equivalents than they sequester; (ii) to reach biodiversity conservation targets, grazing would likely need to cease on some of the land currently used for grazing. To these considerations we can add that ecosystem restoration enabled by pasture reductions would sequester significant amounts of CO2 (Hayek et al., 2021). Moreover, many pastures are currently overgrazed (Tiscornia et al., 2019;Filazzola et al., 2020;Minea et al., 2022;Centeri, 2022). ...
We critically analyzed the "Dublin Declaration of Scientists on the Societal Role of Livestock" (DD), a document promoting animal farming, and its implications for public discourse and policy. Our analysis reveals that the DD is scientifically problematic, particularly in its neglect of issues such as meat overconsumption in high-income countries and the dominance of industrial animal production, thereby downplaying associated risks and harms. We also show that the DD's authors essentially suggest that societies should simply rely on technological progress to fix any "challenges" associated with the sector, a suggestion that aligns with the authors' private interests. We identify several academically questionable practices, including denial of credentials to dissenting actors, omission of significant conflicts of interest, and excessive self-edition and self-citation, all while purporting to provide a scientific and balanced overview. Relatedly, we bring into view conflicts of interests of the Irish semi-state authority Teagasc, which hosted a DD-related summit, and of Animal Frontiers and the animal production science associations behind it, which published a special issue edited by the DD's authors containing the DD. We explore potential responsibilities by these organizations, the DD's authors, and Nature Food, which published a follow-up correspondence by two of the DD's authors. Our perspective contributes to the growing literature exposing the influence of the meat industry on science and its representation in public discourse. We discuss broader policy measures to mitigate and counteract this influence.
... The land footprint of a diet plays a pivotal role in addressing environmental concerns. Its significance is related to inevitable opportunity costs or benefits when one option is chosen over another [56]. In the context of a diet, the land used for growing crops and raising livestock could otherwise be restored to forests or wild grasslands. ...
We investigated how the land footprint of food consumption in Estonia could be decreased through socially acceptable moderate dietary changes while ensuring adequate nutrition. Estonian food consumption was categorized into 14 groups. Five diets were evaluated, including a reference diet, a nationally recommended diet (NRD) by the National Institute of Health Development, and three optimized diets that minimized the consumption land footprint and deviation from the reference diet. The study found that adopting an optimized diet resulted in a decrease in the consumption of milk and red meat, and an increase in the consumption of cereals, tubers, vegetable oils, and nuts, ultimately leading to an up to 56% reduction in the diet-related land footprint. Internal and external land footprints were also estimated using the share of import in the supply. This research offers a highly adaptable modeling framework that could be useful in similar research endeavors.
... Another study on forest carbon sequestration by Houghton and Nassikas (2018) showed that stopping deforestation and allowing secondary forests to grow could result in cumulative negative carbon emissions of 120 PgC between 2016 and 2100 globally. Hayek et al. (2021) investigated this topic from the perspective of animal-sourced food production and showed large potential of carbon storage on land in the absence of animal agriculture. In their more localized study on the current and potential carbon stocks of the forests of a Polish biosphere reserve, Matuszkiewicz et al. (2021) also show a gap between the current and potential C stocks in biomass and quantify this difference to be 66 MgC ha − 1 . ...
... Indeed, extensive land use to produce meat incurs a "carbon opportunity cost (COC)" given that the surplus land could be employed to restore vegetation-rich ecosystems, allowing considerable benefits in terms of carbon capture and increase in biodiversity (Kozicka et al. 2023). Hayek et al. (2021) mapped the magnitude of this opportunity, noting that a shift in global food production to plant-based diets by 2050 could lead to sequestration of 332-547 GtCO2, equivalent to 99-163% of the CO2 emissions budget consistent with a 66% chance of limiting warming to 1.5 °C. ...
Numerous studies highlight the significant negative externalities associated with meat consumption, necessitating a shift towards diets with reduced meat intake. Given the challenges in persuading individuals to reduce meat consumption in their diet and the low popularity of coercive policies, alternative proteins have been proposed as a solution to facilitate the protein transition. This paper stresses the risk that non-holistic analysis of alternative proteins bear in promoting suboptimal solutions, and therefore the need for a multidimensional approach considering aspects such as environmental performance, scalability, acceptability, and animal welfare. For instance, a food product exhibiting favourable environmental performance but lacking scalability potential would likely have minimal transformative impact on food systems. Furthermore, supporting suboptimal solutions generates an opportunity cost in terms of the quantity of meat reduced. Thus, it is crucial to compare alternative proteins not only with conventional meat but also with each other. In this multidimensional analysis, plant-based meats and single-cell proteins emerge as having the greatest potential for contributing to sustainable food systems. Cultivated meat could also contribute positively if it finds a unique market segment and overcomes scalability challenges. Insects demonstrate little promise and should not be considered a sustainable solution given the current state of evidence.
... The results show that shifting livestock practices, especially healthier dietary choices that in many places lead to reduced consumption of cattle-based foods and hence decreased livestock numbers, not only affect methane emissions but are also tightly coupled with CDR strategies (88). Both current pledges for biological carbon removal and BECCS deployment at the scales envisioned in many scenarios likely require large reductions in pasture area, and dietary changes could free up pasture without risking food security. ...
Anthropogenic methane (CH4) emissions increases from the period 1850–1900 until 2019 are responsible for around 65% as much warming as carbon dioxide (CO2) has caused to date, and large reductions in methane emissions are required to limit global warming to 1.5°C or 2°C. However, methane emissions have been increasing rapidly since ~2006. This study shows that emissions are expected to continue to increase over the remainder of the 2020s if no greater action is taken and that increases in atmospheric methane are thus far outpacing projected growth rates. This increase has important implications for reaching net zero CO2 targets: every 50 Mt CH4 of the sustained large cuts envisioned under low-warming scenarios that are not realized would eliminate about 150 Gt of the remaining CO2 budget. Targeted methane reductions are therefore a critical component alongside decarbonization to minimize global warming. We describe additional linkages between methane mitigation options and CO2, especially via land use, as well as their respective climate impacts and associated metrics. We explain why a net zero target specifically for methane is neither necessary nor plausible. Analyses show where reductions are most feasible at the national and sectoral levels given limited resources, for example, to meet the Global Methane Pledge target, but they also reveal large uncertainties. Despite these uncertainties, many mitigation costs are clearly low relative to real-world financial instruments and very low compared with methane damage estimates, but legally binding regulations and methane pricing are needed to meet climate goals.
... 64 Liberating land from animal agriculture and restoring it to wild grassland and forest, under Indigenous and local custodianship, 65 would sequester an estimated 800 billion tons of CO2 from the atmosphere, when including above-ground and below-ground CO2. 66 Sustainable forestry practices could sequester another 600 billion. 67 Even after ocean outgassing, the combined drawdown would approach historical land-use emissions since the dawn of agriculture. ...
Chapter in the edited collection Building Multispecies Resistance Against Exploitation: Stories from the Frontlines of Labor and Animal Rights, edited by Zane McNeill (New York: Peter Lang, 2024). A version was presented at the Ninth Biennial International Herbert Marcuse Society Conference in October 2021.
... The cumulative loss of 116 Pg C from the upper 2 m of soil globally over the past 12,000 years of land use has been termed the soil carbon debt (Sanderman et al. 2017). Third, agricultural land use incurs a carbon opportunity cost, or a reduction in sequestration relative to that which would occur over time in the absence of agriculture (Hayek et al. 2021). As a specific example, the cumulative carbon opportunity cost of land use for livestock production globally is comparable in order of magnitude to the past decade of fossil-fuel emissions, in the hundreds of petagrams of carbon (Hayek et al. 2021). ...
... Third, agricultural land use incurs a carbon opportunity cost, or a reduction in sequestration relative to that which would occur over time in the absence of agriculture (Hayek et al. 2021). As a specific example, the cumulative carbon opportunity cost of land use for livestock production globally is comparable in order of magnitude to the past decade of fossil-fuel emissions, in the hundreds of petagrams of carbon (Hayek et al. 2021). Fourth, agricultural activities result in additional direct emissions, including carbon dioxide (CO 2 ) emissions from farm equipment, methane from livestock and manure, and nitrous oxide from fertilizer use. ...
There is growing interest in enhancing soil carbon sequestration (SCS) as a climate mitigation strategy, including neutralizing atmospheric emissions from fossil‐fuel combustion through the development of soil carbon offset markets. Several studies have focused on refining estimates of the magnitude of potential SCS or on developing methods for soil carbon quantification in markets. We call on scientists and policy makers to resist assimilating soils into carbon offset markets due to not only fundamental flaws in the logic of these markets to reach climate neutrality but also environmental justice concerns. Here, we first highlight how carbon offset markets rely on an inappropriate substitution of inert fossil carbon with dynamic stocks of soil carbon. We then note the failure of these markets to account for intersecting anthropogenic perturbations to the carbon cycle, including the soil carbon debt and ongoing agricultural emissions. Next, we invite scientists to consider soil functions beyond productivity and profitability. Finally, we describe and support historical opposition to offset markets by environmental justice advocates. We encourage scientists to consider how their research and communications can promote diverse soil functions and just climate‐change mitigation.
