The cannabis industry is no stranger to challenges, with inconsistent laws making it extremely difficult to optimise practices or receive funding. This has contributed greatly to the sector’s carbon footprint, as cultivators are often unable to invest in greener energy sources such as solar arrays, while restrictions on transporting weed mean it often has to be grown in locations that lack the climate for outdoor production. Nevertheless, several innovative solutions are finally allowing growers to rise to the challenge of producing more environmentally friendly cannabis.
How Can The Cannabis Industry Become More Environmentally Friendly?
The environmental impact of the cannabis industry has hit the headlines recently, with studies indicating that weed production now accounts for four percent of the total electricity usage in Colorado. Unsurprisingly, this energy usage is driven entirely by indoor production, with lighting, heating, ventilation, and dehumidification requiring a significant amount of power in such grow rooms.
For that reason, a shift to outdoor cultivation is seen by many as the single biggest step that can be taken towards making cannabis more environmentally friendly. Compared to indoor facilities, greenhouses are estimated to produced 42 percent fewer greenhouse gas emissions, while growing outdoors can reduce emissions by as much as 96 percent.
While some believe that weed grown indoors is more potent than cannabis produced outside, some independent analyses have indicated that this simply isn’t the case and that environmentally friendly cannabis that is cultivated outdoors is often loaded with cannabinoids[i]. That said, mismanagement of outdoor growing spaces can still generate major environmental damage, with deforestation, excessive water use, and chemical runoff being among the major harms associated with this cultivation model. Growers are therefore encouraged to take the entire ecosystem into account when growing outdoors and ensure they take measures to prevent pollution and environmental destruction.
Can Cannabis Grown Indoors Be Environmentally Friendly?
Naturally, growing cannabis outdoors is only feasible in locations with the right climate. For this reason, around 40 percent of all the weed produced in California is estimated to be cultivated outdoors, while cold-weather states rely almost entirely on indoor facilities. Colorado is one such state, which is why the City and Council of Denver have published a list of guidelines that are designed to help cannabis growers become more environmentally friendly, even when operating indoors.
To begin with, the guidelines recommend that any facility measuring more than 25,000 square feet conduct an on-site energy audit to reveal and evaluate energy-saving opportunities. One such opportunity involves switching to solar power, which is made affordable thanks to a scheme that has been set up in Colorado that allows owners of solar arrays to sell the power they generate to local homes and businesses. By taking advantage of this programme, cannabis growers can access solar energy without investing in their own panels, thereby eliminating a major cost.
Enviromentally Friendly Cannabis Lighting
In addition, indoor cultivators are encouraged to switch from high-pressure sodium (HPS) to LED lights, which are considerably more efficient. Crucially, LEDs generate much less heat than HPS bulbs, which means less energy needs to be consumed by on-site cooling systems. Regular maintenance of lighting and heating, ventilation, and air-conditioning (HVAC) systems, meanwhile, can increase efficiency, thereby resulting in financial savings and reduced energy consumption.
Adapting growing techniques is another important step that cultivators can take to produce more environmentally friendly cannabis. For instance, switching from a 24-hour light phase to an 18:6 photoperiod during the vegetative stage can significantly reduce energy use without affecting yields. In fact, giving plants a break each night is thought to improve their overall health, preventing them from becoming worn out and resulting in higher quality bud.
In facilities with multiple grow rooms, it is important to stagger lighting schedules over every 24-hour period so that the minimum number of rooms are running at full power simultaneously. According to the guidelines provided by the City and Council of Denver, “any overlap of schedules, even for one hour or less, leads to higher spikes in peak electricity demand and higher costs.”[ii]
Some states have taken action elsewhere in the US to ensure that cannabis growers follow these guidelines and bring down their emissions. In California, for instance, a recent proposal would require all indoor facilities to switch to LED lights by 2023, while Illinois is looking at new legislation that would limit the lighting intensity allowed in grow rooms and require the use of high-efficiency HVAC systems.
Other Ways To Make Cannabis More Environmentally Friendly
Emissions are far from the only problem associated with cannabis use. Plastic packaging and other forms of waste, for instance, must also be addressed if the cannabis industry is to become truly environmentally friendly.
To that end, some producers now convert their leftover plant material into a substance called hempcrete rather than sending it to landfill sites. Hard and extremely durable, hempcrete is a green alternative to concrete and holds the potential for a double-whammy beneficial effect by helping to make both the cannabis and construction industries more environmentally friendly. Importantly, it’s a carbon-negative material, which means its production removes more carbon from the atmosphere than it releases.
To prevent the overuse of plastic, Colorado recently launched a scheme that allows cannabis users to return their used packaging, which is then sterilised, re-labelled, and re-used by dispensaries. In Canada, meanwhile, non-plastic packaging materials such as cardboard are becoming increasingly common.
Each of these solutions represents a step in the right direction. While there’s no denying that commercial cannabis production needs to become much greener than it currently is, environmentally friendly cannabis industry is beginning to emerge.
[i] Mills E. The carbon footprint of indoor Cannabis production. Energy Policy. 2012 Jul 1;46:58-67. – https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.396.4759&rep=rep1&type=pdf