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Double-Edged Leaf: Cannabis and Climate Change

Updated: Aug 13, 2023

Editor’s Note: Today’s post comes from contributing editor Nick Johnson, a historian and editor based in Fort Collins, Colorado. His book Grass Roots: A History of Cannabis in the American West (2017) is a history of cannabis agriculture that explores the environmental and social dynamics of the nation’s most controversial crop. He also blogs (and occasionally podcasts!) about all things cannabis on his website, Hempirical Evidence.

Plants have long held sway over the future of human societies. They are our symbiotic partners on the planet, absorbing the carbon dioxide we breathe out and emitting the oxygen we breathe in. Plants supply us with food, shelter, and medicine—we return the favor with reproduction, granting them abundant progeny.

It is ironic, then, that the industrial revolution, an event that precipitated massive cuttings and die-offs of all kinds of plants across the globe, was in large part fueled by plants. Millions of years of the sun’s energy lay in the dead, compressed bodies of ancient ferns, reeds, and seaweed, crushed or sludged with other organic matter into underground deposits of coal and oil. Humans tapped and burned these masses of photosynthetic energy, harnessing their awesome power for wealth and comfort.

Now, we have reached the age where the promise of fossil fuels has yielded to peril. Hundreds of years of burning fuels is changing almost everything about our world and ushering in an era of accelerating climate change. Heat or rising seas may render large swathes of land uninhabitable. Mega-droughts, mega-storms, and mega-fires rage across entire continents, destroying homes and communities, killing people, sowing political unrest, and polluting air and water. Ready or not, we are being forced to confront the disastrous legacy of our own uncritical faith in the technology and “progress” of the industrial age.

It might seem strange to bring cannabis into this conversation. But, as is typical with cannabis, we find the plant on both sides of this major societal issue. On the one hand, hemp farming can be a powerful weapon to help ameliorate the effects of carbon emissions. On the other hand, industrial cannabis production has a formidable and growing carbon footprint. With the ongoing legalization of the plant and the expansion of its impact on the American economy, it is worth exploring how cannabis might be both a potential cure for and a contributor to climate change—and considering whether the plant can be more beneficial than harmful in this regard.

Cannabis Indoor Grow Operation

Medical Cannabis Growing Operation in Oakland, California, in 2012. Image Courtesy of Rusty Blazenhoff on Flickr.

Cannabis: Climate Saint or Sinner?

As people have looked for magic bullets to fight climate change, some have turned their eyes to hemp. For decades, hemp enthusiasts have claimed that if we just planted enough of the carbon-sucking herb, we could re-orient entire industries—including home construction, car-building, plastics, and even agriculture, itself—away from fossil fuels. If ancient plants fueled the industrial revolution that is now destroying the planet, the argument goes, the multifaceted properties of the modern hemp plant might help buffer or reverse it.


Closeup of a hempcrete wall, 2013. Made from the pulp of the hemp plant, hempcrete is a far more efficient building material than regular sheetrock. Image courtesy of Jnzl on Flickr.

There are compelling aspects to these claims. But there is another side to it, too. Agriculture was fundamentally remade by the industrial revolution, and cannabis farming did not escape such changes. In addition to the invention and mainstreaming of machines like tractors and combines, crops themselves were remade in a “Green Revolution.” In Mexico, American-funded research bred hybrid, high-yielding varieties of corn and wheat that could be grown nearly anywhere in the world—as long as there were enough fossil-fuel-based fertilizers, pesticides, and irrigation networks to support them.

Industrial farming changed drug plants, too. The large populations supported by industrial agriculture craved drugs, resulting in a global expansion of drug-plant agriculture in the late twentieth century. Industrial chemicals like gasoline, ether, and acetic anhydride allowed for the crude chemical extraction of heroin from the poppy and cocaine from coca plants. And huge crops of drug cannabis are now grown indoors in warehouses, accounting for significant percentages of energy use and carbon emissions in states and cities.

So, while hemp may well be a powerful arrow in the anti-climate change quiver, the inputs and emissions from huge crops of drug cannabis are actively contributing to the problem.

The Making of Industrial Cannabis: From Hippies to Halide Lights

Interestingly, the cannabis plant at first resisted industrialization. In the West, it was initially a product of proto-industrial endeavors like slave plantations that produced hemp and cotton (which hemp twine was used to bale). By the early twentieth century, though, after both cocaine and heroin had been synthesized and agriculture had begun its domination of the human landscape, cannabis was not grown on anything approaching an industrial scale. Rather, its place in Western medicine was peripheral and disputed, and its historically popular use as a fiber or rope faded as cheaper or synthetic sources became more readily available.

Then, in the middle of the twentieth century, cannabis became the darling of a countercultural movement whose central aim was the disavowal of an industrial, capitalist existence. Smoking marijuana, with its ability to spur introspection and (at times) quality insight, became both an act of resistance and an example for young people of how the government and mainstream society had gotten things so badly wrong. The conservative backlash to the counterculture produced first Nixon’s and then Reagan’s War on Drugs, both of which focused intensely on cannabis despite comprehensive reports produced by each administration recommending otherwise.

With demand high thanks to the counterculture and with prices high thanks to the interdicting efforts of the drug war, American growers finally industrialized cannabis. Grow operations moved indoors away from drug raiders and under halide lights made possible by the fossil-fuel electric grid. Fans and air conditioners regulated temperatures, and all kinds of agricultural pesticides and fertilizers facilitated the indoor crops. After California legalized medical cannabis in 1996, illicit outdoor grows, too, got bigger every year. Growers used carbon-belching backhoes to clear-cut stands of trees and took abundant water from streams and creeks in the state’s delicate, drought-addled ecosystems.

Carbon Footprint Indoor Cannabis

This graphic shows the wide variety of fossil-fuel inputs required for modern indoor cannabis cultivation. Image from From Evan Mills, “The Carbon Footprint of Indoor Cannabis Production,” Energy Policy 46 (July 2012). (Click on article link to see full-size graphic).

By the time American society began moving away from prohibition in the 2010s, cannabis farming—like the rest of agriculture—was entirely dependent on fossil fuels. In states like Washington and Colorado, indoor cannabis agriculture was uncritically approved and legalized. Where it wasn’t yet legal in places like California, cannabis consumers were served by destructive outdoor cultivation. Quite ironically, the pressures of the Drug War turned the plant of the eco-loving and industry-resistant counterculture into an industrially produced polluter. Most of the cannabis-supporting public and the political class did not seem to notice.

Supplying A Different Demand: Can Industrial Marijuana Be Mended?

But some in the budding legal cannabis industry did recognize weed’s carbon problem. For example, Denver Relief, one of the oldest legal cannabis businesses in the city, transformed its indoor cultivation facility into a model of reuse and sustainability before selling it to Willie Nelson’s company. Denver Relief is now a leading sustainability consultant for cannabis entrepreneurs across the country.

After Massachusetts legalized cannabis in 2016, firms like the Climate Resources Group have advanced the mutual interests of industry partners working toward sustainability. In the absence of unified federal regulation for organically produced cannabis, the nonprofit Cannabis Certification Council offers its own third-party organic certification for cannabis crops and hosts symposia to teach growers how to farm cannabis sustainably. Local laws in states like Illinois and California have also focused more intently on curbing some of the most environmentally damaging practices in cannabis agriculture.

Sustainable Cannabis Grow

Many cannabis cultivators are seeking ways to curb the plant’s carbon emissions. Here, young cannabis plants grow under more efficient LED lighting in Fort Collins, Colorado. Image courtesy of the author.

These small-scale efforts are noble and necessary, and they reflect a growing awareness of cannabis’s contributions to the climate crisis. But they still fall short. As of 2021, growing cannabis indoors still, on average, produces emission levels similar to driving a car. Smoking a joint, emissions-wise, is about the same as eating a hamburger.

Ultimately, the patchwork of state and local sustainability efforts don’t have sufficient power to “green” the industry—that can only come from comprehensive policy, incentives, and enforcement at the federal level. Now that other nations like Canada and Mexico are turning away from prohibition, it would also seem smart to establish multi-national, universal standards for cannabis cultivation.

Cannabis consumers, too, can help in smaller ways. They can choose to buy cannabis from sustainable growers. They can use the power of the consumer dollar to shift industry priorities away from high-powered indoor cannabis to more sustainably farmed greenhouse or outdoor products. Indeed, cannabis investors are well aware of the popularity of “craft” cannabis, which tends to emphasize organic and small-batch cultivation. Like buying a hybrid or electric vehicle, these actions on their own don’t do much, but they contribute to a paradigm shift where we might soon see sustainability sufficiently mainstreamed.

Hemp field

Stands of hemp like this one growing in Oregon have been shown to sequester more carbon than comparable stands of trees. Image courtesy of the Oregon Department of Agriculture on Flickr.

High Time For Hemp?

Of course, we cannot discuss a sustainable cannabis future without talking about hemp. In this respect, the plant’s ability to sequester carbon is perhaps its most valuable asset. Hemp can absorb more carbon than trees or other farm crops, and it grows quickly and easily in most climates around the world—without expensive, fossil-fuel-based inputs.

Combined with strict and drastic cutbacks on carbon emissions, a concerted effort to incentivize and increase our global planting of hemp would be a critical piece of any climate-change strategy. The massive yield from that hemp crop could then be used to create more efficient and sustainable vehicles and structures, as well as medicine, textiles, and other products.

Even though both the cannabis plant and the industry it supports have contributed to the current climate crisis in a number of ways, they do clearly have much more to offer in the way of climate-change mitigation. Climate-conscious citizens, businesses, and politicians must now fully embrace this potential and seek to translate it into policies and a culture that can help remediate the greatest crisis humanity has ever faced.



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