Indoor Farming Revolution Comes with Significant Carbon Cost

Indoor farming could be a powerful solution for producing food in a volatile climate, but the benefits for the food system will come at the cost of a large carbon footprint as long as those new systems depend on natural gas for heat and power.

“Vegetables are increasingly being grown indoors, using an advanced and intensive form of growing called controlled environment agriculture, a method that has the potential to help feed the planet, even while it threatens to further warm it,” reports The New York Times.

Climate change is disrupting food production because of the rising prevalence of unseasonable frosts, droughts, and other adverse weather patterns. But in greenhouses scattered across North America and Europe—collectively covering more than 175 acres of land—”a revolution is quietly taking place, perhaps the most potentially disruptive since Cyrus McCormick’s reaper,” writes the Times, name-checking the Virginia man credited with inventing a mechanical harvesting device in the 1830s.

Using controlled-environment greenhouses, producers can grow crops like strawberries and tomatoes without being affected by calamitous weather events. Indoor food production also uses less water and fewer pesticides, eliminates many food safety concerns, and can unyoke farmers from growing solely in locations with fertile soil, to instead produce food anywhere a greenhouse can be built.

But because many of these greenhouses are powered and heated by natural gas, indoor crops have a higher carbon footprint than their field-grown counterparts. Even those that may be grown right next door are more carbon intensive than foods flown in from far-off places.

“Various studies conducted in the United States, Europe, and Canada have estimated that, on average, the production of a pound of tomatoes in an American or Northern European greenhouse using fossil fuel energy releases 3 to 3.5 pounds of carbon into the atmosphere,” writes the Times, “about six times the carbon footprint of field tomatoes.”

But with diminishing yields threatening food supplies for a human population expected to reach 10 billion people by 2050, proponents say the food system’s vulnerability may leave no other option than to rely on the stability of indoor farming.

“It’s a balance,” said Neil Mattson, who leads Cornell University’s controlled environment agriculture research group. “You put these things on a scale, and you say, OK, which side is weightier than the other side?”

The benefits include “a higher-quality product, more consistent supply, somewhat better control over food safety, and insect and disease control using beneficial insects and microbes instead of conventional pesticides.” But the other side will be weighted by the high emissions and energy costs as long as fossil gas is in the picture.

Affecting that balance is growing investment in the sector, indicating that many see the scale tipping in favour of growing food indoors. “The carbon footprint is the main hurdle we have to clear,” said Mattson. “Then greenhouses are a no-brainer.”