It’s boom time for legal marijuana: In Colorado, revenue from sales is already at $1 billion, and by 2020, the industry is expected to out-earn the National Football League. But while cannabis is big business, it may also be damaging to the environment, according to a new article by environmental scientists William Vizuete and Kirsti Ashworth.
Despite its nickname, weed requires a lot of coddling. When grown indoors, it requires temperatures between 77-86˚F, lots of light, and lots of soil nutrients. It also requires double the amount of water needed to grow wine grapes–a process that was severely stressed by California’s drought. Whether marijuana is grown indoors or outside, it’s clear that it puts a lot of pressure on the environment, yet so far there have been few studies on the effects.
The lack of study around pot’s environmental effects likely has to do with the legal status of the plant. Only a handful of studies have been done on illegal growing operations, but all found that the farms funnel growth nutrients, pesticides, fungicides and other nasties into local waterways, and into the soil. This poisons aquatic life, and leads to other as-yet-unknown effects. “Given that the methods employed in these illegal operations are driven by the need for secrecy,” the authors write in the paper, “the methods have not been optimized to minimize environmental damage.”
The authors also cite studies estimating that indoor growing operations consume power on the same level as computer data centers, and that “illicit grow operations account for 1% of the U.S.’s average energy usage.” Because these operations want to stay off the grid, they use generators to make their own electricity, which triples the carbon output that would result from pulling power from the national grid.
Up until now, the majority of data comes from studying illegal operations; the authors emphasize that further study on legalized operations will present a clearer picture of how much of pot’s negative environmental impacts can be attributed to lack of regulation, and how much is a function of the plant itself. Certainly, regulation won’t fix everything: Though legal weed farms will be able to use cleaner electricity, they will also be operating on a much larger scale, potentially exacerbating the effects water pollution caused by fertilizer and pesticides.
In this light, the recent announcement that the White House plans to crack down on the legal marijuana market will probably make things worse. As long as the legality of commercial growing operations remains uncertain, they will remain hard to regulate and out of the research purview of agencies like the U.S. Department of Agriculture and the Environmental Protection Agency. “The ambiguous legal status of marijuana in the U.S. . . . has made it historically difficult for these agencies to actively fund research in this ﬁeld,” the authors write in the paper.
And that’s a shame because we are in a position to make the marijuana industry into a “progressive, world-leading example of good practice and environmental stewardship,” the authors write. Laws and certification could help to build a sustainable industry, with products labeled as such. Many potential marijuana customers would be interested in environmentally clean products, grown with solar or wind power (if indoors), and responsible use of water and pesticides. Perhaps we would even avoid weed grown in drought-stricken regions like California.
But none of this can happen until we have the research to back it up. Though the authors of this article give guidelines for the best ways to ensure a sustainable industry, they can’t be implemented until we have a stronger research framework around current legal growing operations and a federal plan–neither of which is likely to happen under the Trump administration.