Abstract
The food system is a major driver of climate change, changes in land use, depletion of freshwater resources, and pollution of aquatic and terrestrial ecosystems through excessive nitrogen and phosphorus inputs. Here we show that between 2010 and 2050, as a result of expected changes in population and income levels, the environmental effects of the food system could increase by 50–90% in the absence of technological changes and dedicated mitigation measures, reaching levels that are beyond the planetary boundaries that define a safe operating space for humanity. We analyse several options for reducing the environmental effects of the food system, including dietary changes towards healthier, more plant-based diets, improvements in technologies and management, and reductions in food loss and waste. We find that no single measure is enough to keep these effects within all planetary boundaries simultaneously, and that a synergistic combination of measures will be needed to sufficiently mitigate the projected increase in environmental pressures.
Generated Summary
This research article, titled “Options for keeping the food system within environmental limits”, presents a comprehensive analysis of the environmental impacts of the global food system and explores potential pathways to reduce these impacts, specifically focusing on the period between 2010 and 2050. The study employs a food-systems model that integrates data on food production, processing, trade, and consumption across various regions, alongside environmental footprints related to greenhouse gas emissions, cropland use, bluewater use, and nitrogen and phosphorus application. The primary objective is to assess how the food system’s environmental pressures might evolve under projected changes in population and income levels, and to evaluate different mitigation strategies. These strategies include dietary changes towards healthier, more plant-based diets, advancements in technology and management practices, and reductions in food loss and waste. The study emphasizes that no single measure is sufficient to meet the planetary boundaries and that a synergistic combination of various measures is required to sufficiently mitigate the anticipated increases in environmental pressures. The analysis underscores the critical need for coordinated efforts across multiple sectors to ensure the sustainability of the global food system.
Key Findings & Statistics
- The study estimates that in 2010, the food system emitted approximately 5.2 billion tonnes of carbon dioxide equivalents in GHG emissions, occupied 12.6 million km² of cropland, used 1,810 km³ of freshwater resources (bluewater), and applied 104 teragrams of nitrogen (TgN) and 18 teragrams of phosphorus (TgP).
- The environmental pressures of the food system are predicted to increase by 50–92% across all environmental domains between 2010 and 2050 if no mitigation measures are taken. The greatest increases are projected for GHG emissions (87%), cropland use (67%), and bluewater use (65%).
- Animal products generate the majority of food-related GHG emissions, contributing to 72–78% of total agricultural emissions.
- Animal products also contribute to approximately 10% of bluewater use and 20–25% each of cropland, nitrogen, and phosphorus application.
- Staple crops have generally lower environmental footprints compared to animal products, particularly in terms of GHG emissions.
- Reducing food loss and waste by half could reduce environmental pressures by 6–16% compared to the 2050 baseline, while a 75% reduction could decrease pressures by 9–24%.
- Dietary changes towards healthier diets could reduce GHG emissions by 29% and other environmental impacts by 5–9% (for a dietary-guidelines scenario).
- More plant-based (flexitarian) diets could reduce GHG emissions by 56% and other environmental impacts by 6–22%.
- Combining all medium-ambition measures could reduce environmental pressures by approximately 25–45%.
- Combining all high-ambition measures could lead to a 30–60% reduction in environmental impacts.
- The impacts of the food system would exceed the planetary boundaries for food-related GHG emissions by 110%, for cropland use by 70%, for bluewater use by 50%, for nitrogen application by 125%, and for phosphorus application by 75%.
Other Important Findings
- The study finds that dietary changes towards healthier diets can significantly reduce the environmental impacts of the food system, particularly through a shift away from animal products and towards more plant-based foods.
- Technological and management-related improvements, such as advancements in agricultural yields and fertilizer application, also play a critical role in reducing environmental pressures.
- Reductions in food loss and waste are identified as another key strategy for decreasing the food system’s environmental impact.
- The combination of all the measures has the potential to bring environmental impacts to levels near or even below present impacts.
- The study emphasizes that staying within planetary boundaries requires a multi-faceted approach, combining dietary changes, technological advancements, and reduced food loss and waste.
- The analysis of the planetary option space details the possible combination of measures, showing that staying within the mean value of the GHG boundary requires ambitious dietary change towards more plant-based, flexitarian diets, in combination with either reductions in food loss and waste or technological improvements.
Limitations Noted in the Document
- The study acknowledges uncertainties related to the planetary-boundary values, particularly for bluewater use and nitrogen and phosphorus application, highlighting the challenges of scaling up local environmental pressures to global levels.
- The study recognizes that the planetary-boundary framework provides only a broad measure of sustainability due to the heterogeneity of different boundaries and their underlying scientific bases.
- The study’s scenarios of change focus on changes that are considered realistic or attainable, and do not include technologies or mitigation measures with large uncertainties, such as soil carbon sequestration or landless biomass production.
- The analysis did not assess the impacts that climate change could have on crop yields and freshwater availability, focusing instead on mitigation measures.
- The models used may not fully capture all the feedback effects between different measures of change, potentially limiting the scope of the analysis.
- The study focuses on non-CO2 emissions in agriculture, which may not provide a complete picture, since agriculture and land use also act as sources and sinks for CO2.
- The research acknowledges that grazing is not accounted for in the table and article.
Conclusion
The central conclusion of the study is that the global food system faces significant environmental challenges that are likely to intensify due to population and income growth. However, the analysis reveals that a combination of targeted mitigation strategies can keep the food system within environmental limits. The study strongly supports the implementation of dietary changes, technological improvements, and waste reduction. The study points out that the environmental impacts of the food system could increase markedly owing to expected changes in food consumption and production, and, in the absence of targeted measures, would exceed planetary boundaries to the extent that key ecosystem processes could become at risk of being destabilized. The research suggests that a synergistic combination of improvements in technologies and management, reductions in food loss and waste, and dietary changes towards healthier, more plant-based diets can reduce the impacts, which include a particular emphasis on local contexts and environmental pressures. The article concludes with the call for concerted efforts across various sectors, from the regulatory framework to individual consumer choices. The need to align national food-based dietary guidelines with evidence on healthy eating and environmental impacts is underscored. The success of transforming the food system relies on coordinated approaches, integrating technological advancements, waste reduction, and a shift towards diets that prioritize plant-based foods. “Synergistically combining improvements in technologies and management, reductions in food loss and waste, and dietary changes towards healthier, more plant-based diets, with particular attention to local contexts and environmental pressures, will be a key challenge in defining region-specific pathways for the sustainable development of food systems within the planetary option space.”
IFFS Team Summary
- Important paper by Marco Springmann et al
- Quantifies the impact of various food types, including animal vs plant foods
- Current impact and projected impact in 2050
- Unless there are technological changes and other mitigation measures, there will be 50-90% increased impact
- This is due to both increase population and growing global incomes/per person consumption
- Parameters assessed are
- GHG emissions, Cropland use, Water use, Nitrogen and Phosphorus use
- Note that this paper shows are lower amount of global cropland allocated to animal foods compared to other papers
- This needs further assessment which is not done in this summary
- Estimated impact of animal foods would be impacted by underestimate of this factor
- Also, this paper exclusively looks at cropland and not pasture – see p 9
- Plant based foods have the lowest impact on a per per Kg basis
- The relative impact of three diet scenarios are assessed, including a “flexitarian diet” which includes at least 100 g of legumes, nuts and seeds (which would amount to 20-30 g of protein) and only moderate amounts of animal foods
- There is no higher plant based option, though these calculations can be found in the EAT Lancet 2020 Papers, which utilize this data set, and likely shares data with Sprinmann’s 2020 paper https://www.bmj.com/content/370/bmj.m2322
- Paper emphasizes that plant based diets reduce eco impact are in line with healthier eating
- Also discusses decreased food waste, tech change, eating less
