Demand is booming for organic food. From 2013 to 2018, sales increased nearly 53 percent to almost $48 billion, according to the Organic Trade Association. That sounds like good news for the environment, but is it really?
The first thing to bear in mind is that agriculture, in general, is responsible for a lot of greenhouse gas emissions. In the United States, farming accounts for roughly 9 percent of emissions. About half of those come from the soil. That’s largely because fertilizers, once applied to farmland, generate emissions of nitrous oxide, the third-most-abundant greenhouse gas.
Some organic farming practices, like crop rotation and the use of cover crops, additional plants that can help control erosion and pests, help keep nitrous oxide emissions in check. That’s because they promote healthy soil, and healthy soil releases less nitrous oxide.
Other practices, though, like tilling the soil to get rid of weeds(instead of spraying chemicals), have the opposite effect. Tilling encourages nitrous oxide emissions. Moreover, because it typically produces less food per acre, organic farming tends to need more land, workers and organic fertilizer to stay competitive. That larger scale means larger greenhouse gas emissions.
“There’s pretty good peer-reviewed science arguing that the carbon footprint would actually expand if we were to see a widespread shift to organic, versus having the productivity benefits of conventional production,” said Michael Doane, the global managing director for sustainable food and water at The Nature Conservancy.
Julius McGee, an assistant professor of sociology at Portland State University, said that organic farming had a high carbon footprint because it’s been co-opted by industrial growers that supply big-box stores.
“Large organic retailers rely on cheap organic foods and, in order to produce organics cheaply, you oftentimes operate under the same model as industrial agriculture where you try to reduce costs, and for that you need more inputs, which contributes to more greenhouse gas emissions,” Dr. McGee said.
These retailers, he said, sell under a “gentrification model” that targets middle class buyers — those who can afford to pay a premium for organic food — displacing small farmers selling directly to people via farmers’ markets, community supported agriculture groups or online.
Regardless of whether they have an organic certificate, Dr. McGee said, small farmers tend to have a lower carbon footprint because they “engage in a deeper relationship with the farm and the land.” That often involves growing a wider variety of crops, and smaller farmers don’t typically package their products in single-use plastics or transport them to buyers hundreds of miles away.
Not everybody agrees. Rodale Institute, a nonprofit group that promotes organic farming, argues that some of these studies fail to properly measure how much planet-warming carbon dioxide the soil can absorb when it is cultivated using sustainable methods. Rodale estimates that organic farmland can potentially sequester more carbon than is currently emitted.
But greenhouse gases are only part of the story. The synthetic herbicides and pesticides used in conventional agriculture can be harmful to farm workers and wildlife, especially pollinators and birds, while the natural-gas derived fertilizers are responsible for deadly algae blooms and high methane emissions.
The bottom line: Over all, organic food is probably better for the planet, even if the emissions picture is complex. If you can afford to buy organic, try to go small and local.