Cannabis, marijuana, pot, bud, grass or herb — no matter its nickname, this go-to drug has long been associated with the essence of “green” and connected to eco-friendly movements. Yet, as legalization for medicinal and recreational use gathers pace globally, concerns are rising over the environmental impacts of this nascent industry as it emerges from the shadows of its illicit past.

Both sides of the cannabis business — the legal and illegal markets — are responsible for environmental damage to varying degrees, experts say, potentially contributing to pressures on Earth’s “safe operating space.” Among the concerns are the impacts on freshwater supplies, threats to biodiversity, changes in land use, and potentially vast emissions of CO₂, adding to ever-worsening climate change.

A growing trend

Cannabis is the world’s drug of choice, consumed by an estimated 200 million people annually, according to the United Nations Office on Drugs and Crime (UNODC). A growing number of countries worldwide have passed legislation legalizing its use.

In the U.S., 18 states have legalized cannabis for adult use and 38 for medical use. Malta became the first European country to fully legalize it, and Germany may soon follow suit, with potential ripple effects across the European Union.

This “green rush” is a boon for economies. In the U.S., legal cannabis is expected to generate as much as $43 billion by 2025. Meanwhile, U.S. illegal cultivation continues feeding large swaths of demand to the tune of $65 billion in 2020. With legalization, analyzing environmental impacts is becoming easier as compared to tracking the effects of the clandestine illicit trade.

Many of the environmental harms from cannabis production can be traced to law enforcement policy and the marijuana plant’s historic status as a prohibited crop, according to Anthony Silvaggio, an environmental sociologist at Humboldt State University. In California, for example, enforcement and eradication efforts drove growers deeper into remote, ecologically sensitive areas. “Prohibition, in a sense, incentivizes these sorts of bad actors and these bad practices,” he says.

More recently, Silvaggio points to the controversy surrounding the passage in 2016 of California’s Proposition 64, which legalized cultivation and use by adults in the state, as an example of how legislation helps foster unintentional environmental consequences. “Many folks heralded this legislation, both activists and policymakers, as the environmental gold standard [especially because] it allocated funding to conservation, to restoration, and also the enforcement of environmental laws.”

However, the controversial abrupt removal of a 1-acre (0.4-hectare) limit on legal farm sizes written into Proposition 64 led to a “green rush,” encouraging large-scale growers at the expense of small farmers. [Read More @ Mongabay]