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Learn | 08.27.2021

The Environmental Impact Of Cannabis Grow Operations

Is cannabis as sustainable as we think?

With the increase of cannabis production, one has to question its impact on the environment. Since the legalization of medical marijuana, there have been many environmental studies to see how the cannabis industry might be affecting the world. Not nearly enough though, researchers are still studying the effects of large-scale operations.

The legalization of cannabis has caused its production to become more commercially oriented, and consequently, there is a larger amount of cannabis being produced indoors. Yet we do not know exactly how much the commercialization of cannabis has increased its environmental impact.

Cannabis Waste Disposal

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Thinking about weed, you don’t necessarily jump to the thought of how the scraps get disposed of. Where do the leaves and stems go? What happens to the dead or infected plants? How about any contaminated soil or filtration? Disposing of cannabis waste is like disposing of any trash, some can be composted while others end up in a landfill. 

Cannabis waste has a large impact on the environment. It matters how you dispose of your plants. On a large-scale farm, indoor or outdoor, there are literal tons of plant waste. Organic waste rules have been changing dramatically. Environmentalists have been pushing to make it easier and more efficient to dispose of their plant waste.

The types of waste composting companies are able to take depends on the laws of that state. Green waste (stalks, stems, fan leaves, and roots) and Registered Marijuana Waste (bud, flowers, other plant parts) are the two types of cannabis waste allowable in some states. As not all materials can be composted it can be extremely difficult to keep waste separated.  

Making sure there are no forgery materials in your scrap will make it easier to be composted, unfortunately, that’s not always so easy on larger farms. If something such as even the smallest piece of plastic cannot be broken down, and it won’t, then everything in that batch is going to be tossed into a landfill. To properly dispose of the waste it must be broken down, in retrospect, it can even be used for other agricultural purposes.

Though there are different ways to recycle internally, it’s easier to dispose of waste when you produce tons of plant material a day. Once the material has been composted, it is just that. It is now compost, unusable, and no longer regulated as marijuana waste. Everything gets broken down together which technically means that it can be disposed of as regular waste or repurposed for more composting materials.

Types Of Growing Impacts

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When thinking about the environmental effects of cannabis cultivation, there’s a tendency to focus on the manufacturing process, the chemicals, water, and energy that go into creating it.

However, this recent study found that cannabis itself can be a significant pollutant when grown in large quantities. Cannabis happens to be an extremely versatile plant.

It can grow in different environments, indoor, outdoor, hydroponic, and whatever else science can come up with. 

Impact Of Hydroponic

Hydroponic systems have become extremely popular for cannabis cultivation. They require as little as 10% of the water of a traditional grow and use no soil. This sounds like a win for the environment, but there is one aspect of hydroponics that can be hazardous for the planet: contaminated wastewater.

Water used for hydroponic gardening usually contains a range of nutrients, including nitrogen, sulfur, zinc, phosphorus, and potassium. When the water is discarded, those nutrients may make their way into sewers, streams, lakes, and other water systems.

Unchecked runoff of fertilizers and other agricultural chemicals from farm fields into rivers, lakes, and oceans can lead to the overgrowth of phytoplankton and algae blooms that deplete oxygen levels in the water and release toxins into the environment.

Hydroponic water should always be purified prior to disposal. Small-scale growers can do this using an RO (reverse osmosis) filter, but large commercial cultivators require an industrial solution like a UV (ultraviolet light) disinfection or pasteurization system.

Impact Of Indoor

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Visualizing the magnitude of power it takes to operate an indoor grow operation is the first step to understanding its impact. A considerable amount of legal cannabis is cultivated indoors primarily for quality control and security.

The greenhouse gas emissions are largely attributed to electricity production and natural gas consumption from environmental controls, high-intensity grow lights, and the supply of carbon dioxide for accelerated plant growth.

With a carbon footprint that rivals heavy industrial manufacturing, marijuana is not a field crop. It’s been known to grow in basements, garages, and sheds under artificial light. More annual electricity is needed for indoor grow ops than is produced by the Hoover Dam (which generates enough electricity for Nevada, Arizona, and California).

Cultivating just one kilogram of cannabis from seed to harvest indoors requires 11 times the energy equivalent of driving a car from Manhattan to Los Angeles. 

A lot of the impact also depends on where cannabis is grown. Different parts of the country require different levels of energy. Indoor pot production requires large amounts of electricity and heating, resulting in emissions. Lighting is the most obvious energy-sucking aspect of indoor grows operations, but heating, cooling, or, in some places, dehumidifying the air also requires huge quantities of electricity.

Impact Of Greenhouse

Commercial cannabis greenhouses are larger structures made of steel and usually covered by a poly plastic film that allows for the right amount of sun to penetrate the greenhouse.

Cannabis greenhouses are built for large-scale production with rows of benches or flood tables, trollies, and other greenhouse components.

In addition to the long-term savings in electricity, the greenhouse has minimal restrictions on plant height with greater yields compared to most indoor facilities. Its natural sunlight shining through the roof and walls makes it ideal for producing “sun-grown” strains without the headaches that come with outdoor vegetation.

Though there are fewer environmental downfalls with a greenhouse, there are still impacts. Varying from the material the physical greenhouse is composed of, to any and all internal components.

The external design and materials used to construct the greenhouse will vary quite a bit depending on the location and grower specifications.

Some places, such as those with extreme varying temperatures, may require more materials and more heat than a greenhouse in the tropics.

Impact Of Outdoor

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While greenhouse and indoor operations can take steps to reduce their carbon footprints like collecting and reusing water, soil, and other natural resources, growing cannabis outdoors is the most energy-efficient method of production. Greenhouse and outdoor operations also significantly reduce greenhouse gas emissions.

Though the waste yields are similar, if not, the same as other grow operations, the actual cultivation is what has the most impact. Cannabis cultivated under the full spectrum of the sun brings a much more complex plant. With greater yields and lower costs, outdoor cultivation seems like the perfect choice, but that is not always the case. 

Unfortunately, the sun is free but there is no off switch. The weather can be quite unforgiving on some outdoor grow operations that are not in the best climatic conditions. Plants grown outdoors are exposed to all of the elements, including the environment, weather, pests, and animals.

This can have a very big effect on the final cannabis flowers. There is also the chance the entire growth will be completely destroyed by outdoor elements.

The Law vs. The Environment

While government regulations can encourage more sustainable practices, we shouldn’t be too quick to reject the business owners who have the most to lose. Lawmakers should design policies with cannabis cultivators in mind.

Though there are state-regulated licenses that allow for large-scale cannabis cultivation, that does not necessarily mean they have options for things such as waste disposal. For example, massive cultivation sites have to go through a variety of legal paperwork before they can even plant a single seed.

How Can We Repair The Damage?

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Repairing the damage the environment has suffered is not an easy task. It may even seem impossible. Though hemp is known to decontaminate soil, it might not be enough to repair the damage caused by greenhouse gases and other pollutants.

As consumers, we need to seek sustainable products. If we care about a sustainable future, the companies we support will care too. We see the sustainability demand play out in the growth of trendy companies such as WholeFoods and Tesla. Sustainability honoring trends are relevant for the cannabis industry as well. 

Regulators also have a responsibility to implement forward-thinking environmental policies around cannabis cultivation. Demand sustainability in cannabis, or otherwise, and entrepreneurs will rise to the challenge. We shouldn’t discount the vital role that consumer demand plays in shaping the future of the cannabis industry, especially with its environmental impacts.

What If It Became Legal Globally?

Think about the growth operations that we don’t see. How are we calculating their impacts? There is a larger weight of pollution on illegal grow operations. Black market cannabis rivals the beer industry in leading revenue. Taking that into consideration, you can only imagine the massive impact on the environment. 

Again, there are steps we can take to reduce the carbon footprint of cannabis grow operations. It’s hard to say what the world would be like if weed was legal everywhere. Everyone would definitely be a lot nicer to each other for starters. Environmentally speaking, hemp can decontaminate soil which can lead to healthier crops and the chain reaction follows.


As much research still needs to be done, we have enough information to determine where to begin the change for a more sustainable future. Demand a more sustainable future. Just like that, make it a trend and make it something billionaires want and can only get when they actually do something that helps the environment. 

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Rachel Abela

Strains Sense: Blue Zkittlez

Rachel Abela

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