Seedsman Blog

The Environmental Impact Of Cannabis Cultivation… And How To Grow Greener Weed

It might be uncomfortable to think about, but it’s important not to turn a blind eye to the fact that everything we consume has an environmental impact – including cannabis. Growers of all sizes therefore have a role to play in reducing the footprint of the marijuana industry, although as a new report in the Oil and Gas, Natural Resources, and Energy Journal[i] points out, a little help from policymakers would go a long way towards making green weed more feasible.

The study looks at the environmental issues surrounding cannabis cultivation and maps out a path towards cleaning up the marijuana landscape, yet insists that this can only be achieved by legalising cannabis worldwide.

Of course, growing cannabis can be as rustic or as high-tech as you like, although most commercial cultivators choose to grow their produce indoors, where they can delicately control the environment in order to maximise their yield. Depending on the size of the operation, these grow houses can use anything from 50 to 200 times the amount of energy consumed by a typical office building[ii], with energy costs accounting for between 20 and 50 percent of the total cultivation cost[iii].

Lighting, cooling and dehumidification make up the bulk of this energy use, though things like heating, water pumping and carbon dioxide injection also play a role. In terms of lighting, the kind of energy-saving lightbulb that takes ten minutes to fully brighten your downstairs loo obviously isn’t going to cut the mustard. Instead, growers tend to favour high-pressure sodium (HPS) lights, which unfortunately aren’t the most economical in terms of energy use.

The report points out that a number of greener alternatives are available, with double-ended HPS fixtures consuming up to 25 percent less energy than standard HPS fixtures[iv]. LED lights, meanwhile, have traditionally been snubbed by most growers, although the authors claim that the latest generation of LED lights now emit more of the full light spectrum rather than focusing on only the red and blue wavelengths, resulting in excellent yields while cutting energy use by half.

Yet it’s here that we come to the crux of the problem. Despite the fact that these green solutions can provide long-term savings in energy bills, they tend to be much more expensive to install than HPS lights. So while it may be profitable to run an environmentally friendly operation over several years, initial set-up costs tend to be prohibitive for most growers.

Similarly, chilled water systems have been found to help growers satisfy their cooling and dehumidification needs with energy savings of around 40 percent compared to standard practices, yet the cost of installing this type of equipment makes it unviable for many cultivators.

By legalising cannabis, however, this initial hurdle could be overcome, as governments would have the power to offer financial incentives to cultivators that adopt clean technologies, while banks would also be able to help growers finance the purchase of this equipment and energy companies could incorporate marijuana growers into their clean energy programmes. Even in the US, where numerous states have legalised or decriminalised cannabis, these solutions are currently not possible as the plant remains illegal at the federal level. As a consequence, the report concludes, the vast majority of cultivators currently have no chance of switching to more energy-efficient equipment.

Fortunately, some private utility companies have already begun working with marijuana growers to help them switch to energy-saving systems. Puget Sound Energy in Washington, for example, covers 100 percent of the cultivator’s increased production costs when transitioning to greener technologies[v].

Of course, not all cultivators use high-tech equipment or grow their plants indoors. In California, for example, many producers have no need for lighting as the sun provides their plants with the full array of colours within the light spectrum, allowing for maximum photosynthesis outdoors. However, recent years have seen the state hit by drought, and the amount of water required for cannabis cultivation often exceeds availability in summer months[vi]. When producers resort to diverting water away from rivers and streams, local wildlife suffers terribly – and that’s not something you want on your conscience every time you spark up.

While there may be no easy solution to the ever-escalating environmental catastrophes now occurring worldwide, legalising cannabis at the federal level would at least allow government agencies to carry out more research regarding best practices, and to educate marijuana growers about how to minimise their footprint.

As usual, therefore, many of the perceived harms associated with cannabis are revealed to be problems of prohibition, and could easily be resolved with a little political will.


[i] Spencer Gill, ‘Budding Marijuana Industry Meets Climate & Environmental Crisis: A Call to Legislative Action’, Oil and Gas, Natural Resources, and Energy Journal, volume 5, number 4, April 2020 – https://digitalcommons.law.ou.edu/cgi/viewcontent.cgi?article=1251&context=onej

[ii] Kelly Crandall, A Chronic Problem: Taming Energy Costs and Impacts of Marijuana Cultivation, EQ RESEARCH, LLC (Sept. 2016), http://eq-research.com/wpcontent/uploads/2016/09/A-Chronic-Problem.pdf.

[iii] Neil Kolwey, A Budding Opportunity: Energy Efficiency Best Practices for Cannabis Grow Operations, SOUTHWEST ENERGY EFFICIENCY PROJECT (Dec. 2017), https://www.swenergy.org/data/sites/1/media/documents/publications/documents/A%20Bud ding%20Opportunity%20%20Energy%20efficiency%20best%20practices%20for%20canna bis%20grow%20operations.pdf.

[iv] Jorge Cervantes, Marijuan Horticulture: The Indoor/Outdoor Medical Grower’s Bible 76-78 (2006)

[v] Hydroelectric Power, PUGET SOUND ENERGY, https://www.pse.com/pages/energysupply/hydro-power

[vi] Jodi Helmer, The Environmental Downside of Cannabis Cultivation, JSTOR DAILY (June 18, 2019), https://daily.jstor.org/the-environmental-downside-of-cannabis-cultivation/.

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Ben Taub