California's Weed Industry Could Be Harming the Environment More Than Logging

Quasi-legal status and a lack of regulatory oversight have allowed marijuana cultivation to take place within sensitive ecosystems.

Marijuana cultivation is taking a toll on the land and is on track to create an environmental crisis if left unchecked.

Writing in the journal Frontiers in Ecology and the Environment, researchers said weed growing is destroying habitats, altering streams, and causing soil erosion and landslides on a scale that’s proportionally worse than logging.

Growing cannabis on one acre of land causes 1.5 times more forest loss and 2.5 times more so-called forest fragmentation — ruining habitats, breaking up contiguous wilderness — than cutting down trees for timber, the researchers found.

“The hot spots of growing tend to be on steep slopes, far from roads and close to the headwaters of tributary streams that are critical fish habitat,” said study co-author Jake Brenner, a geographer at Ithaca College, in an interview with

The problem is largely due to the lack of adequate regulations on weed growing, added Brenner, who said government officials could stem the problem if they applied rules to weed that are now routine for other types of agriculture.

“It’s not that cannabis uses more water than other crops. It’s not that it clears more land than other crops,” he said. “But the way that it is arrayed on the landscape puts those impacts on highly sensitive areas.”

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The researchers based their study on Google Earth images of Humboldt County, the center of a region of Northern California called the Emerald Triangle due to the high numbers of marijuana growers there.

It’s no secret why cannabis farmers are seeking out remote areas.

Since California legalized medical marijuana more than 20 years ago, other states have decriminalized the drug and permitted recreational toking. On January 1, the Golden State will allow retail weed shops to open, likely a giant step in normalizing cannabis.

In Humboldt, logging is a $71 million a year industry, according to the study. Cannabis production is estimated as generating $300 million. Nationwide, legal weed is worth more than $7.6 billion annually, the researcher wrote. That figure is expected to balloon to $21 billion in the next few years alone.

But while demand has grown, the federal government still considers marijuana an illicit substance. Many growers are therefore reluctant to farm their pseudo-illegal crop in the open.

‘What we are trying to do is head off some of those consequences in the environment arena by daylighting this phenomenon.’

Brenner said he was ambivalent about legalization, though he believed it could provide sustainable economic development for rural areas that need investment and jobs.

“I would like to see Humboldt Country thrive and, if cannabis is the way to do that, I would not have a problem with that as long as it doesn’t run into the same environmental destruction issues that other agricultural practices tend to run into,” he said.

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He hoped his research would help policymakers take action to curb the harmful consequences of weed growing while emphasizing the positive. Unfortunately, he said, politicians often fail to entertain honest debates on the topic.

“The ‘reefer madness’ taboo is very much with us today,” said Brenner, referring to the 1939 propaganda film that purported to show the dangers of smoking pot. “If we don’t start being frank with ourselves, we’re going to see fallout. What we are trying to do is head off some of those consequences in the environment arena by daylighting this phenomenon.”