Meeting Future Food Demand With Current Agricultural Resources

Abstract

Meeting the food needs of the growing and increasingly affluent human population with the planet’s limited resources is a major challenge of our time. Seen as the preferred approach to global food security issues, ‘sustainable intensification’ is the enhancement of crop yields while minimizing environmental impacts and preserving the ability of future generations to use the land. It is still unclear to what extent sustainable intensification would allow humanity to meet its demand for food commodities. Here we use the footprints for water, nitrogen, carbon and land to quantitatively evaluate resource demands and greenhouse gas (GHG) emissions of future agriculture and investigate whether an increase in these environmental burdens of food production can be avoided under a variety of dietary scenarios. We calculate average footprints of the current diet and find that animal products account for 43-87% of an individual’s environmental burden compared to 18% of caloric intake and 39% of protein intake. Interestingly, we find that projected improvements in production efficiency would be insufficient to meet future food demand without also increasing the total environmental burden of food production. Transitioning to less impactful diets would in many cases allow production efficiency to keep pace with growth in human demand while minimizing the food system’s environmental burden. This study provides a useful approach for evaluating the attainability of sustainable targets and for better integrating food security and environmental impacts. ©2016 Elsevier Ltd. All rights reserved.

Generated Summary

This research investigates the environmental impacts of future food production and the potential of dietary changes to mitigate these impacts. The study combines methodologies to assess the extent to which production efficiencies and dietary patterns need to evolve to maintain current levels of resource use and emissions by mid-century. Using footprint analysis, the researchers evaluate the resource demands and greenhouse gas (GHG) emissions associated with various dietary scenarios, including the current diet and alternative diets such as Mediterranean, pescetarian, and vegetarian. The core methodology involves calculating average footprints for water, nitrogen, carbon, and land, quantifying resource demands and GHG emissions of future agriculture, and assessing whether improvements in production efficiency can keep pace with the increasing demand for food commodities. The study also examines the environmental tradeoffs and impacts of different dietary choices, providing a quantitative assessment of how changes in efficiency and dietary patterns can combine to increase food supply while minimizing environmental impacts from agriculture. Data on historic diets, harvested area, and agricultural production came from the FAOSTAT database. The research employs linear regressions to extrapolate historical changes in production efficiency and assess the overall environmental burden required to support food production.

Key Findings & Statistics

• Animal products account for 43-87% of an individual’s environmental burden, compared to 18% of caloric intake and 39% of protein intake.
• The current average global diet requires annually: 776 m³ H2O, 15.3 kg N, 299 kg CO2eq, and 0.85 ha.
• Animal products account for the majority of resource use: water (43%), nitrogen (58%), GHG (74%), and land (87%).
• GDP-based diet leads to increased environmental burdens across all metrics.
• The Mediterranean diet shows tradeoffs, increasing nitrogen and water demand, while decreasing land and GHG requirements per capita.
• Pescetarian and vegetarian diets lead to consistent decreases in environmental burdens.
• Average footprint intensities will need to improve substantially (H₂O: 65%, N: 85%, GHG: 72%, Land: 97%) to prevent further increases in environmental burdens.
• Historical changes in production efficiency for 1985 through 2011 were estimated using data from FAO (2015): total agricultural land, nitrogen applied to agricultural land, greenhouse gas emissions from agriculture, and area equipped for irrigation.
• Linear regressions fit to these historical changes in production efficiency (PE; e.g., tonnes of applied N per tonne of food produced) were then extrapolated to the year 2050.
• The percent change in overall environmental burden required to support food production (ΔEB) in year x was calculated as:
• The absence of pork in pescetarian and vegetarian diets contributed to a substantial reduction in per capita GHG emissions.
• The increased consumption of aquaculture seafood in the GDP-based diet led to a sizeable increase in required nitrogen.
• Fruits contribute the largest increase in water demand for the Mediterranean diet.

Other Important Findings

• Projected improvements in production efficiency alone are insufficient to meet future food demand without increasing the total environmental burden.
• Transitioning to less impactful diets would allow production efficiency to keep pace with increased human demand while minimizing the environmental burden.
• The environmental burden of food production is significantly influenced by dietary choices, with animal products being particularly impactful.
• Changes in beef consumption have the most significant impact on land use.
• A GDP-based diet would require increases in all four environmental burdens.
• The Mediterranean diet presents apparent tradeoffs, increasing nitrogen and water demand while decreasing land and GHG requirements per capita.
• Pescetarian and vegetarian diets lead to consistent and marked decreases in environmental burdens.
• The study underscores the need to consider both efficiency improvements and dietary changes to address the environmental impacts of food production.
• The study suggests that a transition away from terrestrial animal products, particularly ruminants, is an important strategy for reducing environmental impacts of the food system.
• The focus of most recent studies has been on whether and how increases in food production can keep pace with growth in demand.
• While food trade remains a necessary feature of the global food system, accompanying trade flows with technology transfers can improve the food security outlook for both the importer and exporter.
• The study shows that certain dietary changes can lead to resource savings across a suite of environmental impacts.
• The study suggests that a new food revolution should not aim at increased human appropriation of natural resources but at changes in consumer habits and improved efficiencies in the production system.

Limitations Noted in the Document

• The study focuses on a global scale, using national-level data, which does not capture inter-country heterogeneity in diets or intra-country inequality in food access.
• The study considers a limited number of future diet scenarios.
• Extrapolations of production efficiency do not account for potential effects of climate change.
• The study does not address interactions between production efficiency and consumption rates (Jevons’ Paradox).
• The study focuses on the global scale utilizing national-level data. As such, it does not capture inter-country heterogeneity in diets as well as intra-country inequality in food access.
• The study considers a limited number of future diet scenarios.
• Extrapolations of production efficiency do not account for potential effects of climate change.
• The study does not address interactions between production efficiency and consumption rates (Jevons’ Paradox).

Conclusion

The study emphasizes that the environmental impacts of food production can be significantly reduced through dietary changes. The research demonstrates that transitioning to alternative diets, such as pescetarian or vegetarian, could substantially lower environmental burdens compared to the current or GDP-based diets. The authors highlight that improvements in production efficiency alone are insufficient to meet future food demand without also addressing dietary patterns. The study suggests that a new food revolution is needed, combining efficiency improvements with changes in consumer habits. The research indicates that the most effective strategies for reducing the environmental burden include a shift away from terrestrial animal products, especially ruminants. The authors highlight that changes to efficiency and consumption patterns are not a panacea for comprehensive reductions in the environmental burden of agriculture but are still essential mechanisms towards realizing environmental sustainability of the global food system. The study provides a useful approach for evaluating the attainability of sustainable targets and for better integrating food security and environmental impacts. The study concludes with the need for a new food revolution combining existing technologies and approaches with a new generation of innovations. The authors also suggest that policymakers can seek a market-based solution for modifying consumption patterns by better incorporating the true environmental costs to produce a food item. This could be combined with internationally defined ‘sustainable targets’ or caps for which each country would then be allowed to implement the solutions most suitable to its economic, social and environmental landscapes.