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, published in Nature, presents a comprehensive analysis of the global food system to determine strategies for keeping it within environmental limits. The study employs a global food-systems model, incorporating country-level detail and accounting for various food production methods and environmental impacts. The primary objective is to assess the potential of different mitigation measures, including dietary changes, technological improvements, and reductions in food loss and waste, to reduce the environmental footprint of the food system by 2050. The study also examines the implications of staying within planetary boundaries related to food production, such as climate change, land use, freshwater use, and biogeochemical flows. The analysis incorporates various socioeconomic pathways to project future food demand and its environmental consequences. The research aims to identify synergistic combinations of measures that can sufficiently mitigate the projected increase in environmental pressures and ensure the sustainability of key ecosystems.
Key Findings & Statistics
- The study estimates that the environmental effects of the food system could increase by 50-90% between 2010 and 2050 without mitigation measures.
- In 2010, the food system emitted the equivalent of 5.2 billion tonnes of carbon dioxide in GHG emissions, used 12.6 million km² of cropland, used 1,810 km³ of freshwater resources, and applied 104 teragrams of nitrogen (TgN) and 18 teragrams of phosphorus (TgP) in the form of fertilizers.
- The projected increase in environmental pressures for the food system by 2050, without dedicated mitigation measures, is as follows: 87% increase in GHG emissions, 67% increase in cropland use, 65% increase in bluewater use, 54% increase in phosphorus application, and 51% increase in nitrogen application.
- Animal products generate the majority of food-related GHG emissions (72–78% of total agricultural emissions).
- Reducing food loss and waste by half could reduce environmental pressures by 6-16% compared with the 2050 baseline projection.
- Reducing food loss and waste by 75% could reduce environmental pressures by 9-24%.
- Implementing technological changes could reduce the environmental pressures of the food system by 3–30% compared with the 2050 baseline projection in medium-ambition scenarios, and by 11–54% in high-ambition scenarios.
- Dietary changes towards healthier diets could reduce GHG emissions and other environmental impacts by 29% and 5–9%, respectively, for the dietary-guidelines scenario, and by 56% and 6-22%, respectively, for the more plant-based diet scenario.
- Combining all measures of medium ambition could reduce environmental pressures by around 25-45% compared with the baseline projection for 2050.
- Combining all measures of high ambition could deliver reductions of 30–60%, resulting in environmental impacts that are 20–55% less than the current ones.
- The planetary boundaries define a space around the present values for most environmental domains, with a mean value slightly below present values for food-related GHG emissions, at current values for cropland use, slightly above present values for bluewater use, and substantially below present values for nitrogen and phosphorus application.
Other Important Findings
- The greatest increases along this baseline pathway are projected for GHG emissions, then for the demand for cropland use, bluewater use, phosphorus application, and nitrogen application.
- Specific food groups vary in their environmental impacts, with animal products generating the majority of food-related GHG emissions.
- The projected population and income growth changes the relative contribution of each food group to environmental impacts.
- Technological changes include improvements in agricultural yields and fertilizer application, increases in feed efficiency, and changes in management practices.
- Dietary changes can reduce environmental impacts by replacing animal products with less intensive food types.
- The study highlights the importance of combining multiple measures to achieve significant environmental benefits.
- Combining all measures of medium ambition could result in total environmental impacts within 15% above and below present impacts.
- Combining all measures of high ambition could result in environmental impacts that are 20–55% less than current ones.
Limitations Noted in the Document
- The planetary-boundary framework is subject to criticism, particularly because of the heterogeneity of different boundaries and their underlying scientific bases, including the difficulty of defining global ecosystem thresholds for local environmental impacts.
- The planetary boundaries of the food system have a large uncertainty range, which reflects the difficulties of scaling up local environmental pressures to global levels.
- The study focuses on changes that are considered realistic or attainable, or have been set as goals, and does not include technologies or mitigation measures with large uncertainties.
- The study did not assess the impacts that climate change could have on crop yields and freshwater availability.
Conclusion
The study underscores the critical need for a multifaceted approach to address the environmental challenges posed by the global food system. The research suggests that no single measure is sufficient to keep the food system within planetary boundaries simultaneously, emphasizing the importance of a synergistic combination of strategies. The findings clearly demonstrate that significant reductions in environmental pressures are achievable through a combination of measures, including dietary changes toward healthier, more plant-based diets, improvements in technologies and management practices, and reductions in food loss and waste. The environmental impacts of the food system are projected to increase substantially due to expected changes in food consumption and production, which means that targeted mitigation measures are essential to avoid exceeding planetary boundaries and destabilizing key ecosystem processes. The study emphasizes that the implementation of these measures will depend on the regulatory and incentive frameworks in each region. The authors advocate for aligning national food-based dietary guidelines with evidence on healthy eating and the environmental impacts of diets. The country-specific data and scenarios produced in this study provide a valuable starting point for defining region-specific pathways for the sustainable development of food systems within the planetary option space. The authors highlight the potential for synergistic benefits when combining improvements in technologies and management, reductions in food loss and waste, and dietary changes toward healthier, more plant-based diets. Furthermore, the study suggests that combining ambitious technological improvements with dietary changes and reductions in food waste has the potential to create a food system that is environmentally sustainable, resilient, and aligned with the goals of a healthy population.
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
