Evidence of marijuana use is scattered throughout the archaeological record of human civilization. Residue from most of those excavation sites indicates that the cannabis used by ancient humans was of too low potency to make any determination about its cultivation. This finding has led archaeologists to conclude that the plants were likely wild varieties rather than ones domesticated by humans.
A recent find at a cemetery in the glacier-rich Pamirs of western China, however, indicates that humans may have intentionally selected higher potency strains of marijuana as early as 500 BC.
The research team, which included archaeologists and chemists from the Chinese Academy of Sciences and the Chinese Academy of Social Sciences in Beijing, published their findings in the June 12 issue of the journal Science Advances.
Mark Merlin is a botany professor at the University of Hawaii at Manoa who was a reviewer of the study. “We’ve known that cannabis is one of the oldest cultivated plants in East Asia, primarily for making oil and hemp,” Merlin told NPR. “Now we know the ancients also valued the plant for its psychoactive properties.
The 2,500-year-old Jirzankal Cemetery lies at nearly 10,000 feet (3,000 meters), in present day Xinjiang Uyghyr Autonomous Region, a large province in northwest China. Excavated tombs revealed mummies buried with wood containers, called braziers, used for containing hot coals. Researchers found that the braziers contained cannabis residue.
“We can start to piece together an image of funerary rites that included flames, rhythmic music and hallucinogen smoke, all intended to guide people into an altered state of mind.”Ren, et al
The discovery at Jirzankal is significant because of the strength of the psychoactive component of the cannabis residue, which suggests the plants were either cultivated varieties of high potency, or wild varieties which were intentionally selected for this quality.
The research further underscores the role that glaciers may have played in sustaining the marijuana plants, which have a need for high hydration. A 2015 study on cannabis cultivated in northern California found that an estimated 22 liters of water or more per plant per day were applied during the summer growing season, similar to the water demand of the notoriously thirsty almond tree in the same region.
A wealth of glaciated peaks lie above Jirzankal Cemetery that would have provided melt water for irrigation during the dry season. “Wild cannabis grows across many of the cooler mountain foothills from the Caucasus to western China, especially in the well-watered habitats of Central Asia,” Meng Ren and the co-authors wrote.
Robert Spengler, who worked on the study, is an archaeobotanist at the Max Planck Institute for the Science of Human History, whose work focuses on the spread and intensification of agriculture in ancient Central Asia.
“Further north in Xinjiang, in the Taklamakan Desert, there are other, roughly contemporaneous, finds of cannabis in burials and those populations were clearly living in desert oases that were fed by glacial melt and mountain rain-fed streams that emptied into a hyper-arid desert,” Spengler told GlacierHub. “All of those early populations in Xinjinag were agropastoral and would have relied on glacial melt from the Tian Shan.”
The findings at Jirzankal provoke the imagination to consider the possible role of cannabis in ancient society. “We can start to piece together an image of funerary rites that included flames, rhythmic music and hallucinogen smoke, all intended to guide people into an altered state of mind,” the authors wrote.
Today’s inhabitants of the Pamir mountains are known as Tajiks, one of China’s recognized minorities, who number just over 33,000. They speak Sarikoli, a language in a different branch of the Iranian language family from Tajik spoken in Tajikistan. Tajiks different from the much larger Uygur ethnic community, whom also inhabit Xinjiang.
While the humans of 500 BC embraced marijuana for its psychoactive properties, modern governments have eschewed it, until recently.
A groundswell of popularity and diminishing fear of marijuana has societies around the world slowly welcoming use of the plant back into the mainstream. Barriers to legal access are falling across the United States, and several countries have fully legalized it, including Canada and Uruguay.
Even the Chinese government responded to the shifting views of cannabis, making exemptions on strict laws against marijuana that have been in place since 1985. On May 9, The New York Times ran an article titled “China Cashes in On The Cannabis Boom.” The country produced half of the world’s hemp last year, The Economist reported, though Xinjiang, where the Jirzankal cemetery is located, is not one of the two provinces with special permission to produce the plant.
“Modern perspectives on cannabis vary tremendously cross-culturally, but it is clear that the plant has a long history of human use, medicinally, ritually and recreationally over countless millennia,” Spengler told The New York Times.
And the glacier-marijuana connection is being embraced by American cannabis brands.
The firm Glacier Cannabis is named after Glacier Farms, whose rolling hills in southeastern Michigan were formed by glaciers during the last glacial maximum. “All Glacier cannabis is grown with locally-sourced glacial rock dust,” reads the Michigan company’s brand strategy page.
In the heavily-glaciated Pacific Northwest, a cannabis varietal named “Glacier OG” is bred by RedEyed Genetics, a cannabis seed distributor. Marijuana is also legal in Alaska, the US state with the most glaciers. The rapidly melting glaciers there have contributed more to sea level rise than any glacier region in the world since 1961. A marijuana manufacturer, Glacier Extracts, is based in Anchorage. The operation’s tagline “Not Just Pure: Glacier Pure,” capitalizes on the untainted quality of glaciers.
Humans may have sensed a connection between glaciers and cannabis in 500 BC — or they may have noted the plant’s growth at altitude yielded higher potency buds. “It is possible,” the study authors speculate, “that high-elevation populations of a naturally higher THC–producing variety were recognized and targeted by people in the Pamir region, possibly even explaining the prominence of ritual sites in the high mountains.