Abstract

Feeding a growing, increasingly affluent population while limiting environmental pressures of food production is a central challenge for society. Understanding the location and magnitude of food production is key to addressing this challenge because pressures vary substantially across food production types. Applying data and models from life cycle assessment with the methodologies for mapping cumulative environmental impacts of human activities (hereafter cumulative impact mapping) provides a powerful approach to spatially map the cumulative environmental pressure of food production in a way that is consistent and comprehensive across food types. However, these methodologies have yet to be combined. By synthesizing life cycle assessment and cumulative impact mapping methodologies, we provide guidance for comprehensively and cumulatively mapping the environmental pressures (e.g., greenhouse gas emissions, spatial occupancy, and freshwater use) associated with food production systems. This spatial approach enables quantification of current and potential future environmental pressures, which is needed for decision makers to create more sustainable food policies and practices. Feeding a growing, increasingly affluent population while limiting environmental pressures of food production is a central challenge for society. Understanding the location and magnitude of food production is key to addressing this challenge because pressures vary substantially across food production types. Applying data and models from life cycle assessment with the methodologies for mapping cumulative environmental impacts of human activities (hereafter cumulative impact mapping) provides a powerful approach to spatially map the cumulative environmental pressure of food production in a way that is consistent and comprehensive across food types. However, these methodologies have yet to be combined. By synthesizing life cycle assessment and cumulative impact mapping methodologies, we provide guidance for comprehensively and cumulatively mapping the environmental pressures (e.g., greenhouse gas emissions, spatial occupancy, and freshwater use) associated with food production systems. This spatial approach enables quantification of current and potential future environmental pressures, which is needed for decision makers to create more sustainable food policies and practices. The global food system imposes significant pressure on our environment. These pressures are generated by the inputs, processes, and outputs required to produce different food types and are associated with every stage of production, processing, distribution, consumption, and wastage.1Poore J. Nemecek T. Reducing food’s environmental impacts through producers and consumers.Science. 2018; 360: 987-992Crossref PubMed Scopus (1340) Google Scholar Currently, food production uses around 50% of habitable land2FAOFAOStat. Food and Agriculture Organization of the United Nations, 2019http://www.fao.org/faostat/en/#homeGoogle Scholar and 4% of sea area,3Amoroso R.O. Parma A.M. Pitcher C.R. McConnaughey R.A. Jennings S. Comment on “Tracking the global footprint of fisheries.”.Science. 2018; 361: eaat6713Crossref PubMed Scopus (25) Google Scholar accounts for about 70% of global freshwater withdrawal,4FAOWater for Sustainable Food and Agriculture: A Report Produced for the G20 Presidency of Germany. Food and Agriculture Organization of the United Nations, 2017http://www.fao.org/3/a-i7959e.pdfGoogle Scholar and is responsible for 26% of all anthropogenic greenhouse gas (GHG) emissions.1Poore J. Nemecek T. Reducing food’s environmental impacts through producers and consumers.Science. 2018; 360: 987-992Crossref PubMed Scopus (1340) Google Scholar These pressures lead to impacts on natural ecosystems, degrading and destroying habitats that drive biodiversity declines5Maxwell S.L. Fuller R.A. Brooks T.M. Watson J.E.M. Biodiversity: the ravages of guns, nets and bulldozers.Nature. 2016; 536: 143-145Crossref PubMed Scopus (799) Google Scholar and undercutting the sustainability and production potential of the entire food production system.6Dangour A.D. Mace G. Shankar B. Food systems, nutrition, health and the environment.Lancet Planet. Health. 2017; 1: e8-e9Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar,7Benton T.G. Bailey R. The paradox of productivity: agricultural productivity promotes food system inefficiency.Glob. Sustain. 2019; 2: e6Crossref Scopus (42) Google Scholar These effects are expected to intensify as the human population and per capita consumption continue to grow.8Motesharrei S. Rivas J. Kalnay E. Asrar G.R. Busalacchi A.J. Cahalan R.F. Cane M.A. Colwell R.R. Feng K. Franklin R.S. et al.Modeling sustainability: population, inequality, consumption, and bidirectional coupling of the earth and human systems.Nat. Sci. Rev. 2016; 3: 470-494PubMed Google Scholar Both reducing food's environmental footprint and providing safe, nutritious, and sufficient food to humanity are central components of the United Nations Sustainable Development Goals9United NationsTransforming Our World: The 2030 Agenda for Sustainable Development. Springer Publishing Company, 2017Google Scholar and require comprehensive and spatially explicit understanding of the cumulative pressures and impacts of all food types across the production process. Maps of individual environmental pressures from specific food sectors exist,10Mekonnen M.M. Hoekstra A.Y. The green, blue and grey water footprint of crops and derived crop products.Hydrol. Earth Syst. Sci. 2011; 15: 1577-1600Crossref Scopus (1120) Google Scholar,11Herrero M. Havlik P. Valin H. Notenbaert A. Rufino M.C. Thornton P.K. Blummel M. Weiss F. Grace D. Obersteiner M. Biomass use, production, feed efficiencies, and greenhouse gas emissions from global livestock systems.Proc. Natl. Acad. Sci. U S A. 2013; 110: 20888-20893Crossref PubMed Scopus (596) Google Scholar but cumulative maps are currently lacking.12Halpern B.S. Cottrell R.S. Blanchard J.L. Bouwman L. Froehlich H.E. Gephart J.A. Sand Jacobsen N. Kuempel C.D. McIntyre P.B. Metian M. et al.Opinion: putting all foods on the same table: achieving sustainable food systems requires full accounting.Proc. Natl. Acad. Sci. U S A. 2019; 116: 18152-18156Crossref PubMed Scopus (47) Google Scholar Mapping the location and magnitude of the cumulative environmental footprint of food production is needed to identify hotspots of environmental pressures and potential inefficiencies (i.e., environmental pressure per unit production, Box 1) to inform sustainable policies and practices. Further, accounting for cumulative pressures arising from food production allows evaluation of the most problematic pressures, including those that could lead to unacceptable or avoidable environmental outcomes.Box 1GlossaryAs in many disciplines, numerous terminologies—often conflicting or interchangeable—have been used in the context of environmental impacts. Here, we suggest a four-step structure, based on the terminology described by Judd et al.:13Judd A.D. Backhaus T. Goodsir F. An effective set of principles for practical implementation of marine cumulative effects assessment.Environ. Sci. Policy. 2015; 54: 254-262Crossref Scopus (73) Google Scholar pressures, pathways, impacts, and pressures per unit production.Environmental pressures (Figure 1, step 1), “life cycle inventory (LCI) results” in LCA14Verones F. Bare J. Bulle C. Frischknecht R. Hauschild M. Hellweg S. Henderson A. Jolliet O. Laurent A. Liao X. et al.LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative.J. Clean. Prod. 2017; 161: 957-967Crossref PubMed Scopus (87) Google Scholar and “stressors” or “anthropogenic drivers” in cumulative impact assessments,15Halpern B.S. Walbridge S. Selkoe K.A. Kappel C.V. Micheli F. D’Agrosa C. Bruno J.F. Casey K.S. Ebert C. Fox H.E. et al.A global map of human impact on marine ecosystems.Science. 2008; 319: 948-952Crossref PubMed Scopus (4210) Google Scholar,16Vörösmarty C.J. McIntyre P.B. Gessner M.O. Dudgeon D. Prusevich A. Green P. Glidden S. Bunn S.E. Sullivan C.A. Liermann C.R. et al.Global threats to human water security and river biodiversity.Nature. 2010; 467: 555-561Crossref PubMed Scopus (4083) Google Scholar are the consumptive inputs (e.g., land, water), processes and outputs (e.g., excess nutrients, GHG emissions) associated with producing food. Pressures can be highly variable across space and time and depend on the type of food being produced and the method of production. For example, fertilization contributes to the environmental pressure of eutrophication potential and nitrous oxide emissions, but the magnitude of the contribution will depend on the type of fertilizer and the timing and method of application.17Han Z. Walter M.T. Drinkwater L.E. N2O emissions from grain cropping systems: a meta-analysis of the impacts of fertilizer-based and ecologically-based nutrient management strategies.Nutr. Cycl. Agroecosys. 2017; 107: 335-355Crossref Scopus (54) Google ScholarEnvironmental pathways (Figure 1, step 2) refer to the mechanisms through which pressures contribute to resulting impacts and are not necessarily constrained to the site of production. In LCAs, pathways are often referred to as the “midpoint impact category.”14Verones F. Bare J. Bulle C. Frischknecht R. Hauschild M. Hellweg S. Henderson A. Jolliet O. Laurent A. Liao X. et al.LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative.J. Clean. Prod. 2017; 161: 957-967Crossref PubMed Scopus (87) Google Scholar For example, fertilization results in the environmental pressures (Figure 1, step 1) of phosphorus and nitrogen inputs into the environment that, in turn, might cause the environmental pathway (Figure 1, step 2) of eutrophication (i.e., increased nutrient pollution) at the farm level, or perhaps much further downstream through infiltration into waterways.18Bouwman L. Goldewijk K.K. Van Der Hoek K.W. Beusen A.H.W. Van Vuuren D.P. Willems J. Rufino M.C. Stehfest E. Exploring global changes in nitrogen and phosphorus cycles in agriculture induced by livestock production over the 1900-2050 period.Proc. Natl. Acad. Sci. U S A. 2013; 110: 20882-20887Crossref PubMed Scopus (567) Google Scholar Importantly, although the conversion between pressures and pathways is typically assumed to be linear, these relationships could be highly complex and exhibit both positive and negative feedbacks.13Judd A.D. Backhaus T. Goodsir F. An effective set of principles for practical implementation of marine cumulative effects assessment.Environ. Sci. Policy. 2015; 54: 254-262Crossref Scopus (73) Google Scholar,19Halpern B.S. Fujita R. Assumptions, challenges, and future directions in cumulative impact analysis.Ecosphere. 2013; 4: art131Crossref Scopus (141) Google ScholarEnvironmental impacts of food production, or “endpoint impact category” in LCA terminology, depend on the environmental pathways and the sensitivity (i.e., vulnerability) of an environmental or societal receptor to a given pathway (e.g., population, habitat, or other entity(ies) that would be affected if exposed to the given pressure(s)).14Verones F. Bare J. Bulle C. Frischknecht R. Hauschild M. Hellweg S. Henderson A. Jolliet O. Laurent A. Liao X. et al.LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative.J. Clean. Prod. 2017; 161: 957-967Crossref PubMed Scopus (87) Google Scholar,15Halpern B.S. Walbridge S. Selkoe K.A. Kappel C.V. Micheli F. D’Agrosa C. Bruno J.F. Casey K.S. Ebert C. Fox H.E. et al.A global map of human impact on marine ecosystems.Science. 2008; 319: 948-952Crossref PubMed Scopus (4210) Google Scholar,16Vörösmarty C.J. McIntyre P.B. Gessner M.O. Dudgeon D. Prusevich A. Green P. Glidden S. Bunn S.E. Sullivan C.A. Liermann C.R. et al.Global threats to human water security and river biodiversity.Nature. 2010; 467: 555-561Crossref PubMed Scopus (4083) Google Scholar Thus, the product of these factors describes the expected consequence(s) of a pressure for people and/or nature (Figure 1, step 3). For example, the abstraction of large amounts of groundwater (higher environmental pressure) from a heavily modified, species-poor river in a wet climate (lower sensitivity), might have relatively lower environmental impacts than smaller abstraction (lower environmental pressure) from an unmodified, species-rich river in a relatively dry climate (higher sensitivity). Notably, impacts on humans can be measured by using the same overall approach by considering the social or health vulnerability of a human population to an environmental pathway based on intrinsic (e.g., age, existing health conditions, genetics) and extrinsic (e.g., socioeconomic vulnerability, access to health care) variables.20Huang G. London J. Mapping cumulative environmental effects, social vulnerability, and health in the San Joaquin Valley, California.Am. J. Public Health. 2012; 102: 830-832Crossref PubMed Scopus (19) Google Scholar,21Solomon G.M. Morello-Frosch R. Zeise L. Faust J.B. Cumulative environmental impacts: science and policy to protect communities.Annu. Rev. Public Health. 2016; 37: 83-96Crossref PubMed Scopus (61) Google Scholar Importantly, there might be temporal delays in impacts (decades or longer) because of legacies of historical accumulation (e.g., delayed release by aquifers and sediments).Finally, environmental pressures, pathways, or impacts per unit production (Figure 1, step 4) can be calculated by standardizing environmental pressures, pathways, or impacts by a common unit of food system production (e.g., calories, grams of protein, or servings). Standardization allows meaningful comparisons between locations and across food types in relation to production levels (Box 3). Without considering production levels, low overall environmental pressures because of low production levels can appear to be less environmentally damaging within the context of the global food system than high-production, high-pressure systems. However, the environmental pressures per unit production might be higher. Calculating and spatially mapping pressures per unit production helps to uncover practices that are relatively more efficient and elucidate where specific policies and regulations can produce the biggest benefits through reducing the environmental pressure per unit production. Importantly, both pressures and pressures per unit production should be considered together to account for these potential trade-offs. As in many disciplines, numerous terminologies—often conflicting or interchangeable—have been used in the context of environmental impacts. Here, we suggest a four-step structure, based on the terminology described by Judd et al.:13Judd A.D. Backhaus T. Goodsir F. An effective set of principles for practical implementation of marine cumulative effects assessment.Environ. Sci. Policy. 2015; 54: 254-262Crossref Scopus (73) Google Scholar pressures, pathways, impacts, and pressures per unit production. Environmental pressures (Figure 1, step 1), “life cycle inventory (LCI) results” in LCA14Verones F. Bare J. Bulle C. Frischknecht R. Hauschild M. Hellweg S. Henderson A. Jolliet O. Laurent A. Liao X. et al.LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative.J. Clean. Prod. 2017; 161: 957-967Crossref PubMed Scopus (87) Google Scholar and “stressors” or “anthropogenic drivers” in cumulative impact assessments,15Halpern B.S. Walbridge S. Selkoe K.A. Kappel C.V. Micheli F. D’Agrosa C. Bruno J.F. Casey K.S. Ebert C. Fox H.E. et al.A global map of human impact on marine ecosystems.Science. 2008; 319: 948-952Crossref PubMed Scopus (4210) Google Scholar,16Vörösmarty C.J. McIntyre P.B. Gessner M.O. Dudgeon D. Prusevich A. Green P. Glidden S. Bunn S.E. Sullivan C.A. Liermann C.R. et al.Global threats to human water security and river biodiversity.Nature. 2010; 467: 555-561Crossref PubMed Scopus (4083) Google Scholar are the consumptive inputs (e.g., land, water), processes and outputs (e.g., excess nutrients, GHG emissions) associated with producing food. Pressures can be highly variable across space and time and depend on the type of food being produced and the method of production. For example, fertilization contributes to the environmental pressure of eutrophication potential and nitrous oxide emissions, but the magnitude of the contribution will depend on the type of fertilizer and the timing and method of application.17Han Z. Walter M.T. Drinkwater L.E. N2O emissions from grain cropping systems: a meta-analysis of the impacts of fertilizer-based and ecologically-based nutrient management strategies.Nutr. Cycl. Agroecosys. 2017; 107: 335-355Crossref Scopus (54) Google Scholar Environmental pathways (Figure 1, step 2) refer to the mechanisms through which pressures contribute to resulting impacts and are not necessarily constrained to the site of production. In LCAs, pathways are often referred to as the “midpoint impact category.”14Verones F. Bare J. Bulle C. Frischknecht R. Hauschild M. Hellweg S. Henderson A. Jolliet O. Laurent A. Liao X. et al.LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative.J. Clean. Prod. 2017; 161: 957-967Crossref PubMed Scopus (87) Google Scholar For example, fertilization results in the environmental pressures (Figure 1, step 1) of phosphorus and nitrogen inputs into the environment that, in turn, might cause the environmental pathway (Figure 1, step 2) of eutrophication (i.e., increased nutrient pollution) at the farm level, or perhaps much further downstream through infiltration into waterways.18Bouwman L. Goldewijk K.K. Van Der Hoek K.W. Beusen A.H.W. Van Vuuren D.P. Willems J. Rufino M.C. Stehfest E. Exploring global changes in nitrogen and phosphorus cycles in agriculture induced by livestock production over the 1900-2050 period.Proc. Natl. Acad. Sci. U S A. 2013; 110: 20882-20887Crossref PubMed Scopus (567) Google Scholar Importantly, although the conversion between pressures and pathways is typically assumed to be linear, these relationships could be highly complex and exhibit both positive and negative feedbacks.13Judd A.D. Backhaus T. Goodsir F. An effective set of principles for practical implementation of marine cumulative effects assessment.Environ. Sci. Policy. 2015; 54: 254-262Crossref Scopus (73) Google Scholar,19Halpern B.S. Fujita R. Assumptions, challenges, and future directions in cumulative impact analysis.Ecosphere. 2013; 4: art131Crossref Scopus (141) Google Scholar Environmental impacts of food production, or “endpoint impact category” in LCA terminology, depend on the environmental pathways and the sensitivity (i.e., vulnerability) of an environmental or societal receptor to a given pathway (e.g., population, habitat, or other entity(ies) that would be affected if exposed to the given pressure(s)).14Verones F. Bare J. Bulle C. Frischknecht R. Hauschild M. Hellweg S. Henderson A. Jolliet O. Laurent A. Liao X. et al.LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative.J. Clean. Prod. 2017; 161: 957-967Crossref PubMed Scopus (87) Google Scholar,15Halpern B.S. Walbridge S. Selkoe K.A. Kappel C.V. Micheli F. D’Agrosa C. Bruno J.F. Casey K.S. Ebert C. Fox H.E. et al.A global map of human impact on marine ecosystems.Science. 2008; 319: 948-952Crossref PubMed Scopus (4210) Google Scholar,16Vörösmarty C.J. McIntyre P.B. Gessner M.O. Dudgeon D. Prusevich A. Green P. Glidden S. Bunn S.E. Sullivan C.A. Liermann C.R. et al.Global threats to human water security and river biodiversity.Nature. 2010; 467: 555-561Crossref PubMed Scopus (4083) Google Scholar Thus, the product of these factors describes the expected consequence(s) of a pressure for people and/or nature (Figure 1, step 3). For example, the abstraction of large amounts of groundwater (higher environmental pressure) from a heavily modified, species-poor river in a wet climate (lower sensitivity), might have relatively lower environmental impacts than smaller abstraction (lower environmental pressure) from an unmodified, species-rich river in a relatively dry climate (higher sensitivity). Notably, impacts on humans can be measured by using the same overall approach by considering the social or health vulnerability of a human population to an environmental pathway based on intrinsic (e.g., age, existing health conditions, genetics) and extrinsic (e.g., socioeconomic vulnerability, access to health care) variables.20Huang G. London J. Mapping cumulative environmental effects, social vulnerability, and health in the San Joaquin Valley, California.Am. J. Public Health. 2012; 102: 830-832Crossref PubMed Scopus (19) Google Scholar,21Solomon G.M. Morello-Frosch R. Zeise L. Faust J.B. Cumulative environmental impacts: science and policy to protect communities.Annu. Rev. Public Health. 2016; 37: 83-96Crossref PubMed Scopus (61) Google Scholar Importantly, there might be temporal delays in impacts (decades or longer) because of legacies of historical accumulation (e.g., delayed release by aquifers and sediments). Finally, environmental pressures, pathways, or impacts per unit production (Figure 1, step 4) can be calculated by standardizing environmental pressures, pathways, or impacts by a common unit of food system production (e.g., calories, grams of protein, or servings). Standardization allows meaningful comparisons between locations and across food types in relation to production levels (Box 3). Without considering production levels, low overall environmental pressures because of low production levels can appear to be less environmentally damaging within the context of the global food system than high-production, high-pressure systems. However, the environmental pressures per unit production might be higher. Calculating and spatially mapping pressures per unit production helps to uncover practices that are relatively more efficient and elucidate where specific policies and regulations can produce the biggest benefits through reducing the environmental pressure per unit production. Importantly, both pressures and pressures per unit production should be considered together to account for these potential trade-offs. A key reason for this knowledge gap is the boundaries between academic disciplines that have developed methodologies for different aspects of comprehensive impact assessments: life cycle assessment (LCA) and cumulative impact mapping. LCA aims to understand the environmental aspects and potential impacts throughout a product's complete life cycle (i.e., cradle to grave)22ISOEnvironmental Management - Life Cycle Assessment - Requirements and Guidelines. International Organization for Standardization, 2006https://www.iso.org/standard/37456.htmlGoogle Scholar from an industrial ecology perspective. Recent LCA meta-analyses have clearly demonstrated that not all food is equivalent in terms of environmental pressure per unit production, providing insight into the opportunities and risks within the global food system and allowing for the development of generalized recommendations for more sustainable diets.1Poore J. Nemecek T. Reducing food’s environmental impacts through producers and consumers.Science. 2018; 360: 987-992Crossref PubMed Scopus (1340) Google Scholar,23Tilman D. Clark M. Global diets link environmental sustainability and human health.Nature. 2014; 515: 518-522Crossref PubMed Scopus (1590) Google Scholar,24Hilborn R. Banobi J. Hall S.J. Pucylowski T. Walsworth T.E. The environmental cost of animal source foods.Front. Ecol. Environ. 2018; 16: 329-335Crossref Scopus (111) Google Scholar Methods for conducting regionalized LCAs have recently been proposed,25Bulle C. Margni M. Patouillard L. Boulay A.-M. Bourgault G. De Bruille V. Cao V. Hauschild M. Henderson A. Humbert S. et al.IMPACT World+: a globally regionalized life cycle impact assessment method.Int. J. Life Cycle Assess. 2019; 24: 1653-1674Crossref Scopus (134) Google Scholar but most LCAs do not describe the fine-scale spatial distribution of environmental pressures (total and per unit production),26Hauschild M. Spatial differentiation in life cycle impact assessment: a decade of method development to increase the environmental realism of LCIA.Int. J. Life Cycle Assess. 2006; 11: 11-13Crossref Scopus (143) Google Scholar, 27Bare J.C. Life cycle impact assessment research developments and needs.Clean. Technol. Environ. Policy. 2010; 12: 341-351Crossref Scopus (76) Google Scholar, 28Liu K.F.-R. Hung M.-J. Yeh P.-C. Kuo J.-Y. GIS-based regionalization of LCA.J. Geosci. Environ. Protect. 2014; 02: 1-8Crossref Google Scholar which is critical for predicting impacts on ecosystems and improving sustainability. Furthermore, most food LCAs have focused on one or a few relatively well-studied production types and environmental pressures12Halpern B.S. Cottrell R.S. Blanchard J.L. Bouwman L. Froehlich H.E. Gephart J.A. Sand Jacobsen N. Kuempel C.D. McIntyre P.B. Metian M. et al.Opinion: putting all foods on the same table: achieving sustainable food systems requires full accounting.Proc. Natl. Acad. Sci. U S A. 2019; 116: 18152-18156Crossref PubMed Scopus (47) Google Scholar and usually report results per individual pressure at global or national scales. Results from LCAs that use spatially disaggregated input data, such as land-use change, soil erosion, and/or water scarcity, often differ sharply from non-spatially explicit examples,14Verones F. Bare J. Bulle C. Frischknecht R. Hauschild M. Hellweg S. Henderson A. Jolliet O. Laurent A. Liao X. et al.LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative.J. Clean. Prod. 2017; 161: 957-967Crossref PubMed Scopus (87) Google Scholar,29Potting J. Schöpp W. Blok K. Hauschild M. Site-dependent life-cycle impact assessment of acidification.J. Ind. Ecol. 1998; 2: 63-87Crossref Scopus (122) Google Scholar, 30Boulay A.-M. Motoshita M. Pfister S. Bulle C. Muñoz I. Franceschini H. Margni M. Analysis of water use impact assessment methods (part A): evaluation of modeling choices based on a quantitative comparison of scarcity and human health indicators.Int. J. Life Cycle Assess. 2015; 20: 139-160Crossref Scopus (64) Google Scholar, 31Chaplin-Kramer R. Sim S. Hamel P. Bryant B. Noe R. Mueller C. Rigarlsford G. Kulak M. Kowal V. Sharp R. et al.Life cycle assessment needs predictive spatial modelling for biodiversity and ecosystem services.Nat. Commun. 2017; 8: 15065Crossref PubMed Scopus (52) Google Scholar, 32FAOGlobal Livestock Environmental Assessment Model. Food and Agriculture Organization of the United Nations, 2018http://www.fao.org/gleam/en/Google Scholar, 33van Zelm R. van der Velde M. Balkovic J. Čengić M. Elshout P.M.F. Koellner T. Núñez M. Obersteiner M. Schmid E. Huijbregts M.A.J. Spatially explicit life cycle impact assessment for soil erosion from global crop production.Ecosyst. Serv. 2018; 30: 220-227Crossref Scopus (16) Google Scholar highlighting the importance of considering environmental pressures at finer scales. Largely independent of the LCA literature, conservation scientists have also improved our ability to combine and map pressures and impacts of human activities on the environment across spatial scales.12Halpern B.S. Cottrell R.S. Blanchard J.L. Bouwman L. Froehlich H.E. Gephart J.A. Sand Jacobsen N. Kuempel C.D. McIntyre P.B. Metian M. et al.Opinion: putting all foods on the same table: achieving sustainable food systems requires full accounting.Proc. Natl. Acad. Sci. U S A. 2019; 116: 18152-18156Crossref PubMed Scopus (47) Google Scholar,15Halpern B.S. Walbridge S. Selkoe K.A. Kappel C.V. Micheli F. D’Agrosa C. Bruno J.F. Casey K.S. Ebert C. Fox H.E. et al.A global map of human impact on marine ecosystems.Science. 2008; 319: 948-952Crossref PubMed Scopus (4210) Google Scholar,16Vörösmarty C.J. McIntyre P.B. Gessner M.O. Dudgeon D. Prusevich A. Green P. Glidden S. Bunn S.E. Sullivan C.A. Liermann C.R. et al.Global threats to human water security and river biodiversity.Nature. 2010; 467: 555-561Crossref PubMed Scopus (4083) Google Scholar Similar to LCA, a well-documented set of best practices and assumptions for spatial accounting that combine multiple sources of pressure have emerged, including methods to translate these pressures into impacts.19Halpern B.S. Fujita R. Assumptions, challenges, and future directions in cumulative impact analysis.Ecosphere. 2013; 4: art131Crossref Scopus (141) Google Scholar,34Korpinen S. Andersen J.H. A global review of cumulative pressure and impact assessments in marine environments.Front. Mar. Sci. 2016; 3https://doi.org/10.3389/fmars.2016.00153Crossref Scopus (73) Google Scholar,35Stock A. Micheli F. Effects of model assumptions and data quality on spatial cumulative human impact assessments: uncertainty in human impact maps.Glob. Ecol. Biogeogr. 2016; 25: 1321-1332Crossref Scopus (48) Google Scholar However, unlike LCAs, these mapping assessments rarely account for the cumulative environmental footprint across multiple steps of a production cycle (e.g., processing, transportation, and packaging), which is essential in the context of food production where each stage of the process can impose different environmental pressures with unique footprints (e.g., through feed linkages; see Note S1). In addition, estimates of the environmental pressures of food production need to be scaled by a production metric (per unit) to assess efficiency, a standardizing step in LCAs that is less common in cumulative impact mapping. Thus, to ensure that food production policies are sensitive to location-specific contexts, it is necessary to merge the spatially explicit nature of cumulative impact mapping with the standardization and life stage approach of LCAs. The ultimate goal

Highlights

  • The global food system imposes significant pressure on our environment

  • We demonstrate how to account for feed and on-farm environmental pressures by using greenhouse gas (GHG) emissions from beef and salmon aquaculture

  • As the human population races toward 10 billion people, the need to rapidly develop effective policies to guide sustainable food production is critical

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Summary

Introduction

The global food system imposes significant pressure on our environment. These pressures are generated by the inputs, processes, and outputs required to produce different food types and are associated with every stage of production, processing, distribution, consumption, and wastage.[1]. The feed pressures become clear when exploring the differences of mapping pressures to where they are incurred versus the final animal production site (Box 2, figure panel A versus B and D versus E) In another example, salmon aquaculture is known to have relatively low environmental pressures per unit production compared with that of beef,[1,24] when assessed spatially, salmon aquaculture has higher total GHG and freshwater withdrawal per grid cell. Substantive improvements can be iteratively made over time to achieve a more comprehensive assessment of uncertainty

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EXPERIMENTAL PROCEDURES

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