As more states legalize weeds, their commercial production increases. It is possible that these growing operations will not only raise customers, but also raise the temperature of the planet.
A new study published in Nature Sustainability on Monday aims to quantify the climate impact of indoor cannabis cultivation across the country. The authors, who are researchers at Colorado State University, wanted to see how big these operations would be if they were set up anywhere in the country.
“Political decision-makers and consumers do not pay much attention to the environmental impact of the cannabis industry,” said Jason Quinn. an associate professor of theirechical eDepartment of Engineering at Colorado State University and lead author of the study wrote in an email. “There are few or no emissions regulations for indoor cannabis cultivation. Consumers do not consider the effect on the environment either. This industry is growing and expanding very fast, regardless of the environment. ”
Many cannabis growers prefer indoor cultivation to outdoor cultivation because it provides greater control over plant habitats and greater security. But these indoor operations come at a cost to the climate because they require heating, ventilation and air conditioning to maintain the ideal levels of temperature and humidity and high-intensity rising lights that stay on non-stop. They also often pump into one regular supply of carbon dioxide to accelerate plant growth and increase profits.
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To find out how large carbon-intensive weeds are, the research team developed a model to track the energy and materials used for the type of indoor storage-style growing operation that 41% of American growers use. The model was designed to mimic a typical landfill itself, supplemented with HVAC, grow lights, pesticides and fungicides, water applied by drip irrigation “at an average rate of 3.8 liters per plant per day” and much more.
Because temperatures and humidity in the United States vary widely, the authors’ model calculated the energy needed to maintain these indoor climatic conditions using one-year hourly weather data from more than 1,000 locations across the country. Using data on emissions from the electricity grid across the country, the model then showed the greenhouse gas emissions it will produce with all the energy it needs. In addition, the model took into account “upstream” emissions from the production and transport of water, fertilizers, fungicides and carbon dioxide bottles to grow homes and also aimed at “downstream” pollution of greenhouse gases. greenhouse of all the waste that these operations send to landfills.
In conclusion, the authors found that the cumulative greenhouse gas emissions created by one of these indoor culture depots were between 5,033 pounds (2,283 kilograms) and 11,428 pounds (5,184 kilograms) of carbon equivalent per 2.2 pounds. pounds (1 kilogram) of dried flower. In other words, the eighth weed you buy (legally, of course) comes with a carbon footprint of up to 41 kilograms (19 kilograms).
The authors say it shouldn’t destroy your buzz, though. We must not give up weed growth. We just need to start moving the industry to outdoor growth operations.
“If indoor cannabis cultivation were fully converted to outdoor production, these preliminary estimates show that the state of Colorado, for example, would see a reduction of more than 1.3% in the state’s annual [greenhouse gas] emissions, ”says the study. This means that Colorado will only see a reduction of 2.3 million tons of carbon equivalent each year, which the study notes is almost equal to emissions from the entire coal mining sector in the state.
The results of the study suggest that 80% of greenhouse gas emissions from cannabis cultivation are caused by “practices directly related to indoor cultivation methods, in particular indoor environmental control, high-intensity growth lights and the provision of carbon dioxide for increased plant growth. “Yes, outdoor growth still requires the transportation of materials and equipment and results in waste being sent to landfills – issues we should continue to work on. But it is much less energy consuming, the authors found.
Of course, outdoor growth may not be possible in every part of the country. So, within states, the authors also identified locations where indoor growth is relatively less energy consuming. In Colorado, for example, “the practice of growing cannabis in Leadville leads to 19% more GHG emissions than in Pueblo,” because the former tends to be colder. In climates where outdoor growth could work, policy makers should take steps to initiate the transition. This includes changing regulations and zoning codes to allow for more of these outdoor operations.
But all this is just a first step, say the authors. Much more research is needed to make this growing industry more sustainable.