The Marijuana Boom Is Contributing to the Climate Crisis

As nine states prepare to vote on legalizing pot, a new study predicts energy consumption by indoor cannabis farms will soon rival that of data centers.

Pot farm; server farm. (Photos: Drew Angerer/Getty Images; Jonathan Nackstrand/AFP/Getty Images)

What’s the carbon cost of legal marijuana?

It turns out that every little joint and edible adds up. A new report finds that marijuana cultivation accounts for as much as 1 percent of energy use in states such as Colorado and Washington.

The electricity needed to illuminate, dehumidify, and air-condition large growing operations may soon rival the expenditures from big data centers, which themselves emit an estimated 100 million metric tons of carbon into the atmosphere every year.

The marijuana industry’s energy use “is immense,” said the report’s author, Kelly Crandall, an analyst for EQ Research, a clean energy policy research institute. Her report found that a large grow operation can have energy expenditures of 2,000 watts per square meter because of its constant need for lighting and ventilation.

The carbon cost of cannabis is likely to grow. In November nine states will vote on marijuana legalization, including California, which could become the biggest player in the legal marijuana industry.

Crandall, who started studying the issue a few years ago while working as the energy strategy coordinator for the city of Boulder, Colorado, said she was surprised “by the magnitude of the industry and its utility bills.” She said she was also struck by how hard it was for the industry to switch to energy-efficient options. “I find it kind of a conundrum that it’s a very cash-rich industry, but because of banking restrictions it also has a difficulty investing in solar and efficiency.”

Because marijuana cultivation is still a criminal offense under federal law, most banks will not do business with the industry even in states where it is legal.

Stephen Jensen, president of Green Barn Farms in Addy, Washington, acknowledges that financing “is a big problem.” He added that the marijuana industry is in many ways still learning to do business in a new legal framework, which has slowed its adoption of energy-efficient technologies.

“Most of the growers that have converted from this new legal world have come from the indoor space,” he said, which means they are transitioning from working under the radar to operating legally. “That’s what they know and what the industry knows.”

Jensen said his pot cooperative has spent the past two years learning more about growing outdoors, which has allowed it to achieve dramatically lower electricity costs than many other growers. Now it just uses one building to host mother plants and cloning, while the rest is grown in “sun-powered” greenhouses. He said the energy costs average between $1,250 and $1,500 a month, compared with $25,000 to $40,000 for equivalent indoor growing operations in Washington.

Other parts of the industry are also adapting. A program called Certified Kind, based in Eugene, Oregon, offers growers an alternative to the “organic” label, which they are not permitted to use by federal law. The certification not only requires growers to forgo the use of pesticides but also has strict guidelines for energy use and requires growers to conduct energy audits.

In January, Humboldt County, home to a multibillion-dollar marijuana industry, became the first county in California to regulate cannabis cultivation. The board of supervisors gave growers until the end of the year to register and obtain permits that govern their use of water, energy, and rodenticides.

Crandall said her report pulled from utility filings, interviews, and other published information, although primary information and current research into grow centers’ energy costs was hard to find. “It’s pretty difficult to get people to comment on the record about this sort of thing,” she said.

She also found a dearth of other published research about the industry’s energy consumption. The only real prior study appears to have been published in 2012, before states such as Colorado, Oregon, and Washington voted to legalize cannabis. That study estimated that the industry’s energy expenditures at the time were $6 billion per year.


Andrew Black, certification director for Certified Kind, said the legal cannabis industry is evolving quickly, which will allow it to become more energy efficient. “Data that was never collected and analyzed due to cannabis prohibition is starting to come to light,” he said.

“As normal business practices take root in the cannabis community, and especially as the sale price of cannabis drops, I think you will see a concerted effort toward finding the most economically and energy-efficient way to grow the crop.” Both Jensen and Black said they see the future of the industry in outdoor cultivation, not in inefficient warehouse grows.

Meanwhile, local utilities are just starting to look into ways to work with growers. Earlier in the year Washington’s Puget Sound Energy gave a grower called Trail Blazin’ Productions a $152,000 rebate after the organization invested in LED lighting, which uses less energy and produces less heat.

Crandall said the point of her report was not to focus solely on the magnitude of the marijuana industry’s energy use but to point out ways it could begin to collaborate with utilities and other organizations to reduce energy waste. “A lot of my recommendations involve collaborations among types of entities that may not necessarily have worked together in this way,” she said.

“I think utilities don’t quite know how to reach out to an industry like this yet, and the industry doesn’t 100 percent know what their options are.”

She said she hopes her report brings the issue of cannabis’ energy expenditures into the light: “I don’t think anyone wants to discourage energy use, but they do want to discourage wasteful energy use and help people get more opportunities for clean energy.”