Growing cannabis is a resource intensive process requiring vast amounts of water and energy. And with indoor systems demanding near constant lighting and ventilation, cannabis far outpaces the carbon footprint of crops grown outdoors. Let’s take a look at some of the challenges the cannabis industry faces with sustainability and reining in its energy usage.

Cannabis: A Resource Heavy Crop

Much of the cannabis grown in the United States is still grown outdoors. While growers using traditional outdoor methods need large tracts of land and consume significant amounts of water, fertilizer, and pesticides, their footprint is dwarfed by that of indoor cannabis growers.

That’s because cannabis grown indoors requires an almost constant flow of artificial lighting, ventilation, and temperature control. This represents a massive use of electricity that can stress local power grids.

A 2012 study examining the carbon footprint of indoor cannabis production estimated that the practice accounted for about 1% of the total annual electricity use in the United States. The researchers also estimated that one kilogram of dried cannabis flower resulted in the emission of 4,600 kilograms of carbon dioxide, the equivalent output of about 3 million cars.

Although the study is nearly a decade old, this trend still rings true in states where recreational cannabis has been legalized. In 2015, the city of Portland, Oregon experienced seven blackouts attributed to energy use by indoor cannabis growers. And a 2018 report from Denver’s Department of Public Health and Environment revealed that nearly 4% of the city’s electricity was dedicated to cannabis production.

The Information Gap

The problem with power hungry indoor grow operations is now more obvious, especially as the effects of climate change become more apparent. However, one major roadblock to creating meaningful change in the way we grow cannabis is the lack of information.

Cannabis is one of the world’s oldest cultivated crops, yet, until fairly recently, production practices have been shrouded in mystery due to its legal status. Even with more states getting on board with legalization, cannabis remains illegal at the federal level, hampering federally funded research.

As a result, researchers have relied on resource usage information gleaned from law enforcement and growers themselves. “For any other crop, you could find the information in five minutes, online,” explained Van Butsic, environmental scientist at the University of California, Berkeley in a 2019 Nature article exploring the environmental footprint of cannabis.

The Need for Sustainability as the Industry Grows

The cannabis industry is on a path for growth, and as the industry grows, so will its footprint. A 2018 analysis estimated that the industry’s energy use will more than double by 2022. In our next article, we’ll discuss some of the current solutions being put into practice to curb the carbon footprint of cannabis production.