Abstract
Plant-based animal product alternatives are increasingly promoted to achieve more sustainable diets. Here, we use a global economic land use model to assess the food system-wide impacts of a global dietary shift towards these alternatives. We find a substantial reduction in the global environmental impacts by 2050 if globally 50% of the main animal products (pork, chicken, beef and milk) are substituted—net reduction of forest and natural land is almost fully halted and agriculture and land use GHG emissions decline by 31% in 2050 compared to 2020. If spared agricultural land within forest ecosystems is restored to forest, climate benefits could double, reaching 92% of the previously estimated land sector mitigation potential. Furthermore, the restored area could contribute to 13–25% of the estimated global land restoration needs under target 2 from the Kunming-Montreal Global Biodiversity Framework by 2030, and future declines in ecosystem integrity by 2050 would be more than halved. The distribution of these impacts varies across regions—the main impacts on agricultural input use are in China and on environmental outcomes in Sub-Saharan Africa and South America. While beef replacement provides the largest impacts, substituting multiple products is synergistic.
Generated Summary
This research uses a global economic land use model to assess the food system-wide impacts of a global dietary shift towards plant-based alternatives for meat and milk. The study explores scenarios where the consumption of animal products (pork, chicken, beef, and milk) is substituted with novel plant-based alternatives, analyzing the effects on global environmental impacts through 2050. The methodology uses the Global Biosphere Management Model (GLOBIOM), a partial equilibrium model that integrates global agriculture, bioenergy, and forestry sectors. The study considers different levels of substitution (10%, 25%, 50%, and 90%) of animal products with novel alternatives, and analyzes impacts on GHG emissions, land use, biodiversity, food prices, and food security. The study also explores the effects of land restoration within forest ecosystems.
Key Findings & Statistics
- By 2050, a 50% global substitution of animal products with plant-based alternatives results in a 31% reduction in agriculture and land use GHG emissions compared to 2020.
- If agricultural land is restored to forest within forest ecosystems, climate benefits could double, reaching 92% of the previously estimated land sector mitigation potential.
- The restored area could contribute to 13-25% of the estimated global land restoration needs under the Kunming-Montreal Global Biodiversity Framework by 2030.
- Future declines in ecosystem integrity by 2050 would be more than halved.
- Animal source foods (ASFs) account for less than 20% of the global food energy supply, yet are responsible for the majority of negative impacts on land use, water use, biodiversity, and greenhouse gas emissions.
- In the REF scenario, the global prevalence of undernourishment is projected to decline from 8.4% in 2020 to 3.8% in 2050.
- Total demand for crops decreases compared to the REF scenario due to reduced demand for feed.
- At 50% substitution, total crop production is 20% higher in 2050 compared to 2020.
- Prices decline by 14.1% for animal products and 4.9% for crops.
- Undernourishment declines only moderately, to 3.6% (-31 million people compared to REF), with the largest impacts in Sub-Saharan Africa (-17 million people compared to REF).
- Global agricultural area grows by 4% (+219 Mha) in the REF scenario.
- In the 50% substitution scenario, global agricultural area declines by 12%, with forest and other natural land area 1% lower than in 2020.
- 653 Mha of land is released from use as a result of the 50% substitution scenario.
- Increase in nitrogen inputs to cropland compared to 2020 is almost half of that projected in the REF scenario (+34 Mt relative to 2020).
- Water use declines by 10% (-291 km³) instead of increasing.
- GHG emissions decline by 2.1 Gt CO₂eq year¯¹ (31%) in 2050 (on average by 1.6 Gt CO₂eq year¯¹ on 2020-2050).
- In the 50% scenario, China is responsible for 25% of the global crop land abandonment (20.7 Mha).
- Sub-Saharan Africa exhibits the highest potential to reduce forest and natural land loss, by -76.6 Mha compared to REF (37% of the global value).
Other Important Findings
- Substituting multiple products is synergistic, providing larger impacts than substituting individual products.
- Beef replacement provides the largest impacts.
- Projected impacts depend on the processing efficiency associated with the replacement ingredients.
- High processing efficiency leads to a 60% drop in crop use for novel alternatives.
- Land-use change and GHG emissions display non-linear behavior with substitution rates.
- Substitution above 50% provides virtually no further reductions in deforestation or land use CO2 emissions.
- The model reveals vast differences in the impacts among regions.
- China alone is responsible for 25% of the global crop land abandonment.
Limitations Noted in the Document
- The study does not account for the production costs of novel alternatives other than the costs of the crop ingredients.
- The analysis does not consider the impacts of price declines on producers of agricultural commodities.
- The study’s outcomes are presented as an envelope of possible outcomes, with efficient or inefficient assumptions potentially being closer to reality depending on the specific ingredient, by-product, and crop.
- The analysis did not account for the quantity of animal products which would presumably need to be substituted with vegetable oils, such as animal fats.
- The study only models afforestation with locally naturally occurring tree species, which presents a lower bound estimate for carbon removals and biomass production.
- The study does not consider the potential negative impacts of price declines on the producers of agricultural commodities, which could be substantial.
Conclusion
The study demonstrates that substituting 50% of animal source foods (ASFs) with novel alternatives can lead to significant system-wide benefits, including substantial reductions in environmental impacts and improvements in food security. The findings suggest that dietary changes can effectively mitigate climate change and promote biodiversity, especially when combined with land restoration efforts. The study highlights that the benefits of ASF substitution are not evenly distributed, with regional variations in impacts. China and Sub-Saharan Africa show the largest potential for reductions in land-use emissions. However, the authors note that the transition to novel alternatives presents challenges, including potential impacts on farmer livelihoods and the need for policy interventions to support a just transition. The research emphasizes the importance of considering a broad range of factors, including the impacts on human health and animal welfare. The authors also state that a 50% substitution scenario is realistic, especially with the incorporation of novel alternatives and the combination of plant-based with traditional products. The study concludes by asserting that land-use policies and interventions are vital for achieving the full potential of carbon sequestration and biodiversity restoration. These interventions could include the use of incentives, information campaigns, and market-based approaches.