SOUTHERN COLORADO — A new scientific analysis from Colorado State University (CSU) measured greenhouse gas emissions produced from growing cannabis in a standard indoor environment after legalization from state to state. It found that indoor cannabis cultivation leads to a considerable amount of emissions, no matter where it is grown throughout the country.
However a Southern Colorado indoor cannabis grow, designed for sustainability, is excited to see more research being done on the carbon footprint of the industry.
News5 spoke with Hailey Summers, a PhD candidate in mechanical engineering at CSU, who is one of the authors of the study. Summers said the work on this report began around two years ago, and the publication process took about a year. The group developed a model that simulates conditions of indoor grows representative of those they toured in Colorado, and applied it across the country. "Ran that model around the U.S. So, we were looking at both states that were legal and states that weren't, to help inform states before they legalize," said Summers.
Regardless of location, the analysis found that HVAC systems are the largest contributor to overall greenhouse gas emissions, followed by high-intensity grow lights. These tools help create an artificial climate for the indoor plants.
The report also explains indoor cannabis grows can use carbon dioxide (CO2) to increase the photosynthetic activity of the plants, making them mature quicker. However, that supplemental CO2 adds to greenhouse gas emissions.
Summers said the study conducted a holistic approach, looking at things like a fertilizer's manufacturing process, adding any emissions produced at that time to the total tabulation.
The team measured emissions per kilogram of dry flower produced, and it ranged across the U.S. from 2,000-5,000 kilograms of CO2 emitted. The minimum amount was in California, and the highest total was in Hawaii.
According to the study, indoor Colorado cannabis grows are responsible for around the same amount of emissions as coal mining in the state. That only applies to coal mining, and not the actual burning of the product. "An industry that was legalized within a decade has become as big as entire other sectors in our state, and I think that's really where we're trying to pick apart what's going on and provide insight to where we can improve, because we shouldn't be bringing these industries online overnight in the climate crisis that we're in," said Summers.
Factors like the weather or energy grid makeup can impact the amount of CO2 produced at an indoor cannabis grow. Jason Quinn, an associate professor in mechanical engineering at CSU, explained that when wind or solar generates a kilowatt of energy, there are not many emissions produced when compared to coal or natural gas. "Ultimately, this work is dedicated toward just pushing information out to scientists, consumers and policy makers so that we can start to make informed decisions," said Quinn.
Summers said Colorado ranks in the top 25% for the worst states when it comes to indoor cannabis grow emissions. "Regardless of if there's a blizzard happening, your indoor environment has to maintain comfortable growth environment. And so, in Colorado, it's more likely throughout the year that your outside weather is different than what you need inside. So, that takes constant energy to manipulate... Weather is a big thing. But also, our grid emissions, we have a lot of coal and natural gas, so those are contributing... A clean grid won't solve everything, but it is a good step in the right direction," said Summers.
CLICK HERE to read through the full study from CSU.
The analysis noted areas in Southern Colorado are likely more environmentally fit for indoor cannabis grows than other mountain towns in the state. It says places like Leadville, Aspen, Gunnison, and Alamosa have "significantly more greenhouse gas emissions than locations on the plains of Pueblo, Trinidad, or Denver." For instance, growing indoor cannabis in Pueblo has 19% less emissions than Leadville. "These results indicate that individual states can optimize their indoor cultivation locations to reduce greenhouse gas emissions," the report reads.
The owner of AJ's Craft Cannabis and GroGeo, Anthony Mollins, allowed News5 inside their indoor cannabis grow in Southern Colorado on Earth Day. Their underground facility houses their sungrown cannabis, with concrete walls controlling the climate. They also have a retractable greenhouse roof, allowing them to capitalize on the sun, and use their lights less. "Next week, we'll start eliminating the lights and we won't use them at all in the summer," said Mollins.
Mollins' operation does not use a traditional HVAC unit. "You can grow indoor with the sun, but not have to use those huge HVAC units to draw so much power... We use the earth as basically a condensing unit to clean the air, and circulate fresh conditioned air with re-circulated air," said Mollins.
Plus, Mollins said they do not add any supplemental CO2 inside their greenhouse. "Filtered fresh air, rather than pumping CO2 in, your plants will eat that just the same," explained Mollins.
Mollins was excited to see a study like this being done, because their goal is to be sustainable without sacrificing quality. "It really is a wasteful industry sometimes. And, we're trying to show people you don't need to throw things away, you don't need to purchase things unnecessarily, you don't need to use a lot of energy. There's sustainable ways to go about it and still have the top quality cannabis," said Mollins.
The design and concept of Mollins' sungrown indoor plant with a custom HVAC design, GroGeo, will be marketed this summer. The goal is to promote sustainable, craft cannabis.
Here at a #SouthernColorado #cannabis indoor grow, they have a cutting edge design to limit their amount of #greenhousegasemissions. Tonight at 10, we’re breaking down how their sustainable method could be the way of the future. @koaa pic.twitter.com/GaQUCSuHAX— Colette Bordelon (@ColetteBordelon) April 23, 2021