SEATTLE — Marijuana growing is not a green industry.

SEATTLE — Marijuana growing is not a green industry.

Done mostly indoors pot production often uses hospital-intensity lamps, air conditioning, dehumidifiers, fans and carbon-dioxide generators to stimulate plants and boost their potency.

The power-hungry crops rival data centers or server farms in intense use of electricity, according to a peer-reviewed study last year in the journal Energy Policy. One kilo, or 2.2 pounds, of pot grown indoors, the study says, leaves a carbon footprint equivalent to driving across the country seven times. Producing one joint is equivalent to leaving a light bulb on for 25 hours.

There's little question sun-grown pot is a cleaner alternative, even in Washington state, which uses mostly hydropower, considered greener than most energy sources.

"It's great we have relatively low-carbon electricity, but that's not a license to waste it," said KC Golden, policy director for Climate Solutions, a Northwest nonprofit working against global warming.

It doesn't make sense to move agriculture indoors, Golden said, given the sun's track record of "encouraging photosynthesis for some 4 billion years now, without an outage."

But in this blue-green state, very few folks are lobbying for pot grown under the sun in Eastern Washington where the climate is suitable, in part because of security concerns about outdoor grows. And absent a stronger push, it appears state-regulated retail stores will open next year without sun-grown weed on their shelves.

Golden said he hasn't studied the issue, particularly the implications of outdoor pot for law enforcement. Leaders at other environmental groups such as the Sierra Club and Conservation Northwest say they have other priorities. Even in Seattle, where the City Council is writing new zoning rules allowing large indoor grows, no one seems very concerned with the carbon footprint of indoor pot.

Instead, the chief advocates for outdoor pot in the state are Okanogan County activist Jeremy Moberg and state Rep. Joel Kretz, a Republican from Wauconda. They say outdoor pot should be grown in greenhouses that allow in natural sunlight, not expansive open fields.

"The waste of our clean hydropower, wind and solar electricity for a nonfood crop used primarily for recreation is simply unacceptable," Kretz, a rancher, wrote the state Liquor Control Board, the agency charged with carrying out voter-approved Initiative 502. Sun-grown pot also could be an economic boon for his rural constituents, Kretz noted.

And it probably would be cheaper than indoor weed, Moberg said, helping the state achieve its goal of undercutting the black market.

The politics of producing pot are complicated, however, by the federal prohibition of marijuana looming over the state, and a state timeline for opening retail stores that seems to give the entrenched indoor industry a running start in competition with outdoor cultivators.

Gov. Jay Inslee won't comment on pot growing, according to spokesman David Postman, even though the governor recently declared Washingtonians "are the people who are destined to defeat carbon pollution." He doesn't want to micromanage the Liquor Control Board, said Postman.

Still, the board seems somewhat receptive to sun-grown weed.

Sharon Foster, the board's chairwoman, recently said the state would license indoor and greenhouse growing, though not open-field production. Chris Marr, a board member from Eastern Washington, agreed the state agency is leaning in that direction, though no decisions have been made.

Outdoor growing can be made secure with razor-wire fences, surveillance cameras and other measures, according to Dan Williams, president of Canna Security America, a firm based in Colorado where outdoor cultivation is allowed. "It's absolutely doable," Williams said.

California pot activist Steve DeAngelo emphasizes that just an acre of weed can yield enough to sustain a family farm.

"People who care about our environment, who respect Mother Nature, need to make this a priority and demand that rule-makers and regulators allow cannabis to be grown like every other crop in the country," said DeAngelo, while in Seattle recently for a meeting of investors hearing pitches from marijuana entrepreneurs including Williams.

As with grapes, outdoor pot can exhibit traits of the environment it's grown in — what wine aficionados call "terroir."

"Think about it," DeAngelo said. "Do you want to eat tomatoes grown in a hydroponic solution under high-intensity lamps, or do you want tomatoes grown organically under the sun?"

Washington state's new regulated seed-to-store system aims to cripple the black market. Prices are key to that goal. Moberg believes greenhouse production could be considerably less expensive than indoor growing, even with Washington's relatively inexpensive electricity.

Despite all the apparent arguments in his favor, Moberg wasn't able to find allies in the environmental movement.

He turned to Kretz, a lawmaker with a contrarian streak. During a recent debate about wolves, Kretz sponsored a bill that would move wild wolves to the west side of the Cascades. He figured west-side lawmakers loved wolves so much they should have some in their own backyards.

Moberg wrote Kretz a letter saying sun-grown pot was an issue where the socio-economic and environmental arguments favored the east side.

Kretz jumped on it. "I want green marijuana," he said in an interview. "The land here is cheap, we have good soils and lots of sun." Not to mention unemployment of 15 percent in Ferry County, which he represents.

Now that recreational pot is legal, he said his attitude is "let's make the best of the situation, whether you agree or not" with its use.

Meanwhile, Seattle City Hall is rolling out its Climate Action Plan to make the city carbon neutral by 2050; and the City Council's zoning proposal would allow indoor grows up to 50,000 square feet, or more than an acre, in the city. Neither the climate plan nor the zoning regulations mention environmental impacts of producing marijuana in the city.

The issue has not been raised with Mayor Mike McGinn, said his spokesman Aaron Pickus, and McGinn thinks the matter is best left to state regulators.

Council member Nick Licata, sponsor of the new zoning, raised concerns about the security of transporting processed pot to urban markets. "You could have repeats of Al Capone knocking off beer trucks," he said.

Mike O'Brien, who oversees the council's energy committee, said large-scale growers would likely go outside Seattle where land is cheaper. But he said the issue may come up for analysis as the carbon plan is implemented.

"This is one of those rapidly evolving areas on the radar," he said.