How can salad be produced climate neutral?

The indoor growing strategy has environmentalists split. On the one hand, anything that helps shift diets away from carbon-intensive animal products and toward plants is generally considered to be necessary to mitigate warming, including by the experts that make up the United Nations Intergovernmental Panel on Climate Change. But there are challenges to growing enough fresh produce to feed billions. Defying seasons – and, increasingly, extreme weather patterns – takes a lot of energy from an electrical grid that continues to rely heavily on fossil fuels, writes Amelia Bates, with

If Americans want to eat more salad – and going by industry predictions, they do – the supply chain that brings the leaves from the earth to the plate (or the plastic clamshell, as the case may be) has to be both reliable and efficient. According to Di Gioia, farming is no longer a simple business. “It’s more technological, more advanced,” he explained. “You need people there who know what they’re doing, people who are in charge of production, an agronomist, people who are going to check that everything is safe and high quality.” 

That could not be more apparent than at the robot-operated Fifth Season. Only a few sanctioned humans are allowed to wander the aisles of the biodome, given a security clearance and exhaustive sanitation ritual that has little to do with workers’ COVID risk but is meant to protect delicate plants from any number of foreign microbes. Most of the movement in this sterile, cavernous warehouse occurs as a couple of crane-like machines glide up and down the aisles. They pull one little slat of greens from its slot and move it into another, perhaps several times over the course of one day, to perfectly optimize its growing conditions: a little more light, a little less breeze, just this quantity of nutrient-enhanced water.

But Fifth Season’s level of control comes at a cost. It turns out when you recreate the Salinas Valley under a roof, it requires a lot of electricity. Crops need light, water, and soil to grow. On a traditional farm, you might have to pipe in the water and meticulously fertilize and pH-balance the soil, but all that abundant California sun comes free. “We’re talking about substituting that energy indoors,” Ramankutty said. “And that energy cost is too high for anything other than niche crops.”

If your vertical farm is located in a region that depends largely on fossil fuels for its energy – like, say, western Pennsylvania – the carbon footprint of your indoor-grown salad is likely going to exceed that of the one from the farm. That calculation might change as those grids shift to renewable power sources and indoor growing technology becomes more energy efficient. Having more indoor operations located near large East Coast markets could cut down on emissions related to transportation, which usually constitutes the largest portion of lettuce’s carbon footprint. But for most crops, greenhouse growers have a long way to go before those benefits outweigh the energy that goes into heating, cooling, and lighting an indoor farm.

Energy expenditures notwithstanding, the profit-minded case for indoor farming is already compelling enough for some growers to scale up. When Paul Lightfoot founded the mid-Atlantic salad grower BrightFarms in 2010, it was based on what he describes as a sort of well-informed business hunch. Today, BrightFarms grows 6.5 million pounds of baby greens per year in large greenhouses. The company harvests and packages them on-site and distributes them within 200-ish miles of each farm, covering a swath roughly from Wisconsin to Delaware. 

“I knew it wasn’t that old of an industry, it was growing quickly, and it would keep growing,” Lightfoot said. “People would eat more salads and make a better connection between what they’re eating and their health. What I wouldn’t have predicted is that it’s still a fast-growing category, but most growth is coming from indoor salad producers.”

There may, however, be some real environmental benefits to embracing some “unnatural” grow operations in the long term. For all its chilly sterility, the land and water footprints of indoor farms are a small fraction of that of traditional farms. And when you grow everything under one climate-controlled roof within a day’s drive of the grocery store that will be distributing it, a lot of the uncertainty of the supply chain gets eliminated – and along with it, food waste.

Salad – really the entire food system in general – is caught up in this same climate-driven catch-22. Farmers will need to invest in new techniques and technology to keep certain foods available to consumers on demand. Food justice advocates emphasize that giving all communities access to fresh foods must be a part of that equation. But, by the laws of economics, the cheaper a crop becomes, the less incentive there is for profit- and tech-minded, growers to buy in. 

Read the complete article at

Publication date:

Receive the daily newsletter in your email for free | Click here

Other news in this sector:

Sign up for our daily Newsletter and stay up to date with all the latest news!

Subscribe I am already a subscriber