According to ganjapreneur Rick Byrd, the future of farming is tall, dirtless and local.

Byrd’s vision of skyscraper farms to feed city dwellers begins with a much different kind of crop: marijuana.

The 45-year-old is chief executive officer and founder of Pure Agrobusiness Inc., a company that sells equipment to grow legal cannabis, a market worth $6 billion in 2016 and expected to reach $50 billion by 2026, according to Cowen & Co.

Because cannabis has higher profit margins than food, and pot is mostly grown inside, Byrd said he hopes the innovations perfected by PureAgro, with the help of customer feedback, could one day revolutionize food production. It’s just a question of how much it costs.

Pot is “the perfect catalyst to bring in what I think really needs to change in farming,” Byrd said in an interview. “You can’t have the average produce truck going 1,500 miles to get to your plate. And there’s no way, obviously, to farm the amount of acres that we would need to feed New York City unless we go vertical.”

Byrd imagines a 100-story glass skyscraper filled with floors of stacked beds of fruits, vegetables and grain. The same technology that currently enables vertical indoor farms to raise primo weed can one day produce perfect tomatoes or succulent lettuce, Byrd said. Paper or mesh holds up the plants, substituting for soil. Powerful lights do the work now done by the sun, but better. Data calibrate the exact light spectrum and nutrients for the plants to thrive, and machines drip just enough water. Harvests are frequent — four or five a year, compared with one outdoor.

Making urban farms vertical instead of horizontal could cut agriculture’s reliance on fossil fuels and diminish risks from pests, pesticides and an increasingly haywire environment, Byrd said.

Because price is less of a problem with cannabis, pot growers are better able to adapt to new, more expensive technology. An ounce of kale, for instance, costs 49 cents at Whole Foods Market. An ounce of cannabis can run $150 to $200, according to data from BDS Analytics, a research firm. When technology expenses fall low enough, a tipping point arrives, and food farmers can take advantage of what the pot producers already use. With legal weed pushing down pot costs, even marijuana growers will need cheaper technology, Byrd said.

“Who do you think is going to implement technology? Obviously the cannabis guys,” Byrd said.

Air Basil

In some places, Byrd’s dream of vertical food production is already happening. Specialty items — basil leaves, for example — are raised in air farms in places like Brooklyn, New York. Sky Greens, in Singapore, began operating in 2012 to reduce reliance on food imports. Plants are grown using hydroponics — without soil — in an aluminum frame. In the offices of Tokyo-based human-resources company Pasona Group Inc., 20 percent of the space is used to grow vegetables. Ten thousand square feet of growing beds and lights share space with conference rooms and offices. The building produces 100 different kinds of fruits and vegetables.

When Byrd first came across plans for farm-filled buildings nearly a decade ago, he thought they were far-fetched, he said. That was around 2008, as Byrd completed building the first LEED platinum certified home with actor Adrian Grenier, of “Entourage” fame, in a project that was featured on Discovery’s Planet Green channel. Due to the show’s exposure, Byrd received architectural plans for eco-friendly buildings from all over the world, including farms in 100-story high-rises.

“It didn’t pencil out then,” he said. “Then came the cannabis boom.”

Sun and Rain

The problem with growing indoor food, or pot, is missing out on free resources like rain and sun.

“Why would you ever block a non-carbon-emitting source of photosynthetic active radiation that grows plants at no cost?” said Paul Sellew, CEO of Little Leaf Farms, a greenhouse that cultivates produce in Devens, Massachusetts. “It’s a fad, and it will pass.”

But climate change is making outdoor conditions less predictable, said Christiana Wyly, operating partner at Satori Capital LLC, a private equity firm.

Byrd, who likes to wear blue and black Armani and said he doesn’t smoke marijuana, said PureAgro, based in Denver and Los Angeles, recently began working with an investment bank. That’s unusual for a business working with marijuana, which is legal in some form in 28 states but taboo with the federal government.

Shares of publicly traded Scotts Miracle-Gro Co., an agricultural supply company and PureAgro’s competitor, rose 48 percent last year. Now comes the uncertainty of the Trump administration, and a attorney general nominee in Alabama Senator Jeff Sessions, who’s expressed hostility to legal weed in the past, over how they plan to deal with federal drug law.

Given that the majority of the world’s population lives in urban centers, it will eventually be necessary to grow food nearby, said Al Shay, an instructor in the Department of Horticulture at Oregon State University in Corvallis.

But the strength of the land-based farm lobby has kept the indoor industry from spreading more, he said. The cannabis industry could be the spark, he said.

“People toyed around with batteries in cars for a long time,” Shay said. “It wasn’t until Elon Musk came along with Tesla and made it highly efficient and super sexy.”

This story was first published on BloombergNews.com