As more states legalize weeds, their commercial production increases. These growing operations may not only make customers higher – they may also raise the temperature of the planet.
A new study Published Monday in Nature Sustainability aims to quantify the climate impact of indoor marijuana cultivation across the country. The authors, who are researchers at Colorado State University, wanted to find out how greenhouse gas-intensive these operations would be if they were set up all over the country.
“Policymakers and consumers do not pay much attention to the environmental impacts of the cannabis industry,” said Jason Quinn. an associate professor of theyechaniese eengineering department at Colorado State University and lead author of the study, wrote in an email. ‘There is little or no regulation on emissions for the cultivation of cannabis inside. Consumers also do not consider the environmental impact. This industry is developing and expanding very fast without considering the environment. ”
Many marijuana growers prefer indoor cultivation to the outdoors because it provides greater control over the habitat of the plants and more safety. But these indoor operations cost the climate as they require heating, ventilation and air conditioning to maintain the ideal temperature and humidity levels and a high intensity of the growing lights that stay on for 24 hours. They also often pump a regular supply of carbon dioxide to accelerate the growth of plants and increase profits.
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To determine how carbon-intensive growing weeds are, the research team developed a model to track the energy and materials used for the type of indoor growth production in the warehouse style. 41% of American producers use. The model is designed to mimic a typical warehouse, complete with HVAC, cultivation lights, pesticides and fungicides, water applied by drip irrigation, at an average dose of 3.8 liters per plant per day, and more.
As the temperature and humidity in the US vary widely, the author model calculates the energy needed to maintain these indoor climatic conditions using an annual hourly weather data from more than 1,000 locations nationwide. Using electricity network emission data from across the country, the model then showed the greenhouse gas emissions that would provide all the energy needed. In addition, the model emitted the “upstream” emissions from the production and transportation of water, fertilizers, fungicides and bottles of carbon dioxide to homes, as well as the “downstream” greenhouse gas pollution of all the waste that these operations send to landfills.
The authors found that the cumulative emissions of greenhouse gases created by one of these indoor cultivation warehouses were between 2,283 kilograms and 5,184 kilograms of carbon equivalent per 1.2 kilograms of dried flower. . Put another way: the eighth part of the weed you buy (of course, legally) has a carbon footprint of 19 kilograms.
However, the authors say that it does not have to ruin your buzz. We do not have to give up growing weeds. We just need to start moving the industry to more out-of-growth operations.
“If indoor marijuana cultivation were to be completely converted to outdoor production, these preliminary estimates show that the state of Colorado, for example, would see a decrease of more than 1.3% in the state’s annual [greenhouse gas] emissions, ”reads the study. This means that Colorado alone would have an annual reduction of 2.3 million tons of carbon equivalent, which according to the study is roughly equal to the emissions of the state’s entire coal mining industry.
The results of the study indicate that 80% of the greenhouse gas emissions grown by cannabis are caused by “caused by practices directly linked to indoor cultivation methods, specifically indoor environmental control, high intensity greenhouse lights and the supply of carbon dioxide for increased plant growth. “Yes, growing outdoors still requires that materials and equipment be sent and that this still leads to waste being sent to landfills – problems that we have to keep working on. But it is less energy intensive,” the authors found.
Of course, outgrowth may not be possible in every part of the country. Thus, within states, the authors also identified places where the ingrowth is relatively less energy intensive. In Colorado, for example, ‘cannabis use in Leadville results in 19% more GHG emissions than in Pueblo’, because the former is usually colder. In a climate where outside growth can work, policymakers need to take steps to usher in the transition. This includes changing regulations and zoning codes to enable more of these outside operations.
But this is only a first step, say the authors. Much more needs to be done to explore how to make this emerging industry more sustainable.