Let's Nerd Out About... That Carbon Footprint Study
I'm taking a short hiatus, but in the meantime, let's address that carbon footprint study
Hi Gardenerds,
Just a quick update today instead of the full newsletter. Exciting things are happening in my life that I need to focus my limited energy on, so Let’s Nerd Out About Gardening will be taking a short hiatus over the next couple of months.
If you haven’t already, make sure you subscribe so you don’t miss the comeback newsletter.
In the meantime, here’s a study that you may have seen making headlines the past month. The Telegraph seems to have kicked it off with claiming that “Carbon footprint of homegrown food five times greater than those grown conventionally.” (The rest is behind a paywall.)
I haven’t actually read the clickbait articles, since I know how sensationalized academic studies can get in the news. But after watching Gardening in Canada’s response video (she’s a soil scientist), I decided to read the actual study here: Comparing the carbon footprints of urban and conventional agriculture.
(The University of Michigan Record also has a pretty thorough interpretation.)
Here’s a few things I noted:
On average, yes, the urban farms, community gardens, and home gardens studied produced more CO2 per nutritional serving (their way of comparing tomatoes to lettuce) than conventional farms. But when looking at individual urban farms and gardens, some had much lower carbon footprints than conventional farming. (Only collective gardens, like community gardens, were statistically significantly higher than conventional gardens.)
They didn’t study conventional farms themselves, but used other studies. In the U of M Record, one co-author noted that conventional farms are difficult to compete with in efficiency, since they can use monocropping with pesticides and fertilizers to get larger harvests. Even though we know that’s worse for the environment, it lowers their carbon impact. (Although I do wonder if this includes the release of CO2 from tilling up soil. If anyone knows, please share in the comments!)
The biggest factor seems to be infrastructure. So a gardener putting in wood raised beds with a lifespan of 5 years would have a higher carbon footprint than someone putting in galvanized steel or using inground methods. Likewise, a tomato grown in a garden is always going to have a lower carbon footprint than one grown in a commercial greenhouse. But they also note that it’s not always the choice of gardeners — if their community gardens get displaced by land developers and city officials, then all that infrastructure is destroyed.
The researchers support urban agriculture. They just want to point out the ways that gardeners and urban farmers can lower than carbon footprints, especially when that’s one of their stated goals. They also point out that urban agriculture has a lot of social benefits which can offset their larger carbon footprint. So they shouldn’t just focus on minimizing carbon footprints, but in increasing their social benefits. (Also again, carbon footprint is just one small aspect of the greater environmental impact picture.)
It’s your turn: do you consider your gardening carbon footprint? What decisions would you make to offset the impact? What insights did you glean from the study?
Share with us in the comments. We’d all love to get some more ideas.
Happy growing,
Tanith
P.S. No joke this time, but here’s a hint to the next newsletter: this one growing method can help food insecurity and nutritional deficiencies.
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