The environmental costs and benefits of high-yield farming

How we manage farming and food systems to meet rising demand is pivotal to the future of biodiversity. Extensive field data suggest that impacts on wild populations would be greatly reduced through boosting yields on existing farmland so as to spare remaining  natural  habitats.  High-yield  farming  raises  other  concerns  because  expressed  per  unit  area  it  can  generate  high  levels of externalities such as greenhouse gas emissions and nutrient losses. However, such metrics underestimate the overall impacts of lower-yield systems. Here we develop a framework that instead compares externality and land costs per unit produc-tion. We apply this framework to diverse data sets that describe the externalities of four major farm sectors and reveal that, rather than involving trade-offs, the externality and land costs of alternative production systems can covary positively: per unit production, land-efficient systems often produce lower externalities. For greenhouse gas emissions, these associations become more  strongly  positive  once  forgone  sequestration  is  included.  Our  conclusions  are  limited:  remarkably  few  studies  report  externalities alongside yields; many important externalities and farming systems are inadequately measured; and realizing the environmental benefits of high-yield systems typically requires additional measures to limit farmland expansion. Nevertheless, our results suggest that trade-offs among key cost metrics are not as ubiquitous as sometimes perceived.

Balmford, A., Amano, T., Bartlett, H., Chadwick, D., Collins, A., Edwards, D., Field, R., Garnsworthy, P., Green, R., Smith, P., Waters, H., Whitmore, A., Broom, D.M., Chara, J., Finch, T., Garnett, E., Gathorne-Hardy, A., Hernandez-Medrano, J., Mario Herrero., Hua, F., Latawiec, A., Misselbrook, T., Phalan, B., Simmons, B. I., Takahashi, T., Vause, J., zu Ermgassen, Z., and Eisner, R. (2018) The environmental costs and benefits of high-yield farming. Nature Sustainability, 1 , pp. 477-485. https://rdcu.be/bcmoN

This is an output of the CCI Collaborative Fund project No such thing as a cheap lunch? Quantifying tradeoffs between yield and environmental externalities in food production systems.