Urban agriculture may not have fewer emissions

This one surprised me, but it does make sense. A new study by Hawes and colleagues (2024) looked at the emissions of urban agriculture compared to conventional agriculture. There is, not surprisingly, some complexity here but generally speaking the carbon footprint of urban grown produce is six times higher than conventional agriculture. So what causes such a high impact?

The biggest source is the infrastructure like raised beds combined with a short life span. The materials used to build raised beds or paths between beds have high emissions, when they are only used for a few years, those emissions just don’t get spread out over enough crops and the overall footprint stays pretty high.

However, it isn’t all bad news for urban gardeners. Foods that are transported via air and crops grown in greenhouses have higher footprints; therefore, if you are able to grow these in open air pots then you can reduce the carbon impacts. In addition, urban agriculture has some other potential benefits. The urban farmers and gardeners reported mental health, diet, and social benefits. Studies also support improved nutrition.

One more recommendation to reduce the impact of urban agriculture is to use waste like compost, rainwater, and grey water (water from household use like showers and dish washing) in the beds.

This doesn’t mean that urban agriculture shouldn’t be done, but it does raise important issues. We need to pay attention to what we grow and how. And we need to pay attention to the materials used and how long we use them for. No replacing the beds or giving up after just a couple years. Getting into urban agriculture needs to be a long term commitment.