Life Cycle Assessments have been underestimating the value of organic agriculture

Apr 20, 2020

Organic agricultural practices provide many ecosystem services that improve farm production while simultaneously protecting the environment. For instance, organic farming boosts soil health and water quality, and supports important biodiversity. Researchers of a new study in Nature Sustainability say these benefits have been overlooked and ignored when comparing resource use and greenhouse gas emissions (GHG) of agricultural production, resulting in a misguided favor of large-scale, industrialized production. Life Cycle Assessments (LCAs)  have been used for several decades to measure energy use and global warming potential of any given product from “farm to gate.” LCAs are the most commonly used tool to compare the sustainability of different farming practices or systems like organic versus conventional. For example, LCAs might ask how much water, fuel, and greenhouse gases (GHG) are emitted to grow one ton of corn under conventional versus organic management. External factors are also considered, like how much energy is used and GHGs are emitted to produce, deliver, and apply synthetic nitrogen fertilizer for conventional production compared to the requirements to grow and turn in green manure for organic production. Because industrialized production is highly efficient, organic can require more resources to grow the same amount as a conventional product. By focusing on yield, researchers of this study say important benefits of organic practices and critical negative impacts of conventional have been left out of the equation. Land degradation, consequences of pesticide use, and biodiversity losses are some of the environmental impacts that have not been considered in past LCAs when quantifying resource use and global warming potential of industrialized, conventional agriculture. This study offers a way forward that will more accurately represent the benefits of organic agriculture and environmental impacts of industrialized conventional agriculture by adopting a broader perspective beyond output of production.