Is there anything that won’t cause climate change?

A new report indicates that a boom in legalized marijuana farming could come with a high carbon cost.

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.

Marijuana measures are on the ballot in in 9 states, and several of these allow farming of a limited number of plants. California is one of those states:

Proposition 64 would allow adults to possess up to an ounce of pot and grow six marijuana plants at home and levy various taxes on sales that would be deposited into the state’s Marijuana Tax Fund. Most of the money collected will be spent on substance-abuse education and treatment. Some of the fund would be used to repair damage done to the environment by illegal marijuana growers. Recent polls show support for the measure at about 58 to 60 percent.

The environmental damage caused by unregulated marijuana farming in California is not trivial. Humboldt County’s pot farms are destroying the area’s redwood forest ecosystem and killing some of rare wildlife.

“The single biggest threat to our environment right now has been unregulated cannabis,” says Natalynne DeLapp, executive director of the Environmental Protection Information Center, a grassroots group that spearheaded the effort to protect the Headwaters and its wildlife. “In the last 20 years we’ve seen a massive exponential growth in cannabis production in the hills of Humboldt County, and we’ve seen really devastating environmental effects.” Growers have fragmented forests by cutting trees to build greenhouses and roads on steep hillsides, choking creeks home to endangered salmon with sediment, fertilizers, and pesticides and sucking streams dry during a record drought to irrigate marijuana crops. Once-still forests echo with the racket of hundreds of diesel generators. Rat poison and other toxic chemicals used by some growers to protect their plants are killing rare wildlife like the Pacific fisher.

“It’s just been really sad, actually, really sad to see what’s happened to the environment and a lot of work people have put into restoration efforts, to see those things unravel because people continue to bulldoze hillsides for clearings to grow more cannabis,” DeLapp says.

I wonder if President Obama would have been so quick to sign the Paris Climate accord if he knew one of the targets was marijuana?