When Governor Cuomo signed legislation legalizing recreational use of marijuana in New York on March 31, 2021 he ushered in a new era for New Yorkers. That much at least, is not controversial. This is true in spite of the fact that perhaps every other aspect of the legalization of cannabis has become a lightning rod for impassioned debate.

Regardless of your opinions on the costs and benefits of recreational marijuana, it’s worth understanding what the likely environmental impact of this new law will mean.

Much is yet to be determined, but some things already seem clear. Because of the way the legislation is worded, the companies that are already authorized to grow and sell medical marijuana in New York essentially have the inside track to become the largest suppliers to the newly legalized recreational market. And because of the strict requirements for security and chain of custody in the new law, it also seems unlikely that a significant amount of weed will be grown outdoors. Which is understandable but also unfortunate.

Because these two factors taken together virtually guarantee that the future marijuana that recreational consumers buy in New York will have been produced in such a way as to maximize its carbon footprint.

Why? Because there’s now every practical incentive to grow it indoors with the intense electrical usage that accompanies the need for industrial strength lighting, irrigation and ventilation systems.

 

According to the latest scholarship on this topic appearing in Nature Sustainability citing research from Evan Mills in 2012, the carbon footprint of indoor cannabis production is surprisingly large.

Mills claims that the ratio of Green House Gas (GHG) production to cannabis produced for consumption is 4,600 to 1. In other words, for every ounce (or kilogram) of cannabis produced and sold, 4,600 ounces (or kilograms) of GHG are emitted into the atmosphere in the process.

 

Even accounting for the efficiency improvements that have occurred in lighting in the past decade, and assuming that these changes have cut the ratio in half, this is a staggeringly large ratio.

To put it in more tangible terms, that ounce of purple haze you will be able to purchase legally in New York sometime in the next year or two will create the equivalent of 143.75 pounds of GHG even before you take your first puff. That’s like burning almost 27 gallons of gasoline. Now there’s a way to harsh your mellow.

 

But it doesn’t have to be that way. Even if we concede that the legal requirements of growing marijuana for recreational use in New York practically dictate indoor growhouses, or at least greenhouses, these facilities can be made more environmentally friendly. Adding solar power to growhouses and greenhouses (yes that’s possible) can help reduce the environmental toll associated with the cultivation of legal weed. And do so while saving money for growers. Silver Lining Solar can help show you how.

So let’s hope that tomorrow’s gummy bears get a little help from the sun, even if their active ingredient was grown indoors.