The Hidden Environmental Impact of Climbing Chalk
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When the godfather of bouldering, John Gill, started at Georgia Tech in 1954, little did he know that his enrollment in a gymnastics class would lead to a major advent in climbing: the use of gymnastic chalk. “I turned out to be pretty good at the rope climb, but you have to chalk up before you start,” recalls Gill. “And I thought, ‘Well, if you chalk up for this, you might as well chalk up for a climb too.’”
That autumn, Gill brought chalk on climbs at Stone Mountain, Georgia, and on late-night buildering expeditions around Georgia Tech. Recalls Gill, “We’d sneak out of the dorm or fraternity house and go around campus and climb on the buildings, taking a rope with us. And I used to take a block of chalk and put it on my fingers before I climbed … I’m sure we left some interesting handprints.” When Gill expanded his climbing repertoire to include Cloudland Canyon, Georgia, and later the Tetons, he continued bringing chalk and showing others how to use it. Within a decade, people were smearing the stuff on crags worldwide.
Now 80 and living in Pueblo, Colorado, Gill still keeps a block of chalk in his bedroom. He hasn’t used it since he stopped climbing more than a decade ago, but for Gill the block represents a lifetime of memories. Gill started climbing in high school in Atlanta—far from the burgeoning climbing communities out West. Perhaps as a result of this isolation, he found his own trajectory, practicing bouldering as a sport in its own right and training fiendishly for feats of strength, grace, and dynamic movement on the boulders when no one else was doing so. A key part of his art was the chalk he used to dry his hands.
But what Gill used wasn’t ordinary chalk—it was a desiccating compound called magnesium carbonate that, says Michael Silver, climber and CEO of the high-tech materials company American Elements, is also an abrasive: “It both keeps your hands dry and improves your grip—your ability to create some friction between you and the [rock],” he says. Try your project armed with a bag of regular (blackboard) chalk—calcium sulfate, which would simply color your hands white—and you’ll quickly see the difference.
That said, the science is far from settled, with some studies even showing that applying chalk reduces friction, perhaps by creating a lubricating layer between rock and skin. (See “Use of chalk in rock climbing: sine qua non or myth?” in Journal of Sports Sciences; for a counterpoint, see “The effect of magnesium carbonate (chalk) on geometric entropy, force, and EMG during rock climbing” in Journal of Applied Biomechanics.) But that hasn’t stopped it from becoming big business. Today, there are more than 20 companies selling the stuff, each pushing their unique twist. There’s chunky chalk, block chalk, liquid chalk, colored chalk—even “herbal” chalk made with menthol.
There are holdouts. Patagonia founder Yvon Chouinard has long eschewed chalk, as does the Colorado free-climbing pioneer Jim Erickson. There was even a group of Brits in the 1970s known as the “Clean Hand Gang,” including Steve Findlay and Pat Littlejohn, who all refused chalk. But by and large, a chalky-handed climber clinging to a crimp has become the image of the sport. And for good reason: Gill says he doubts his specialty—dynamic motion—would have developed the way it did without chalk. It’s possible that other advances likewise hinge on chalk (can you climb 5.15 without it?). Which makes it all the more incredible that we know so little about the white powder.
So where does magnesium carbonate come from? Currently, “100 percent of the [magnesium carbonate] that’s in the sport is coming from mining,” says Brian Kelleghan, owner of Bison Designs and inventor of the Bison Chalk Ball.
Chalk comes from a mineral called magnesite, found in underground deposits all over the world. It’s whitish or clear, as hard as a penny, and porous enough to stick to your tongue. The mineral is used for other applications besides chalk, from lining steel kilns to making laxatives. “Chalk is a huge commodity item, and our industry makes up a part of that … but a small amount,” says David Lawrence, owner of Joshua Tree Skin Care. World reserves of the non-renewable magnesite sit at about 12 billion tons, meaning it will supply us for hundreds more years. Magnesite is mostly composed of magnesium carbonate, but it has other substances, too. To make climbing chalk (or laxatives), you have to strip away those impurities.
“It’s not that complicated,” says Silver who, to be fair, owns a materials company that creates things like optical laser systems. If you had magnesite lying around, you could probably do it at home. Through a series of baths in hydrochloric acid and baking soda, the various chemical components of magnesite get filtered until it’s just a wet paste of pure magnesium carbonate sitting in a tub of saltwater. The paste then goes into a filter press, a giant accordion-like machine that compresses to wring out the water. Then the paste gets heated in an oven and crushed. “Once you get to a nice, fine particulate, it’s packable material; you can take it and put it into a packing machine and produce blocks,” says Silver. Those blocks get sent to suppliers who might add their own special sauce—Joshua Tree Skin Care, for instance, adds essential oils, while Metolius adds a proprietary “drying agent”—and then into chalk bags all over the world.
“You could easily be climbing a mountain that contained the same chalk you’re using on your hands,” says Silver. “There’s this one material that comes from the same point in nature from which we’re deriving the pleasure of climbing. It’s kind of cool.” But that’s not the whole story. In fact, it’s only the tail end of the process.
“You can look it up on Wikipedia, I guess,” laughs chalk-father Gill, when I ask if he knows where magnesium carbonate comes from. But there is no Wikipedia page. In fact, there is little info about where the industry gets its chalk. Some companies, like Petzl, claim the information as proprietary, while others, like FrictionLabs and Rogue Fitness, say, respectively, that their chalk comes from “all over the world” and “overseas.” However, brands like Black Diamond, Metolius, and Joshua Tree Skin Care say that they get their chalk from China, mostly northeast China. (Kelleghan gets Bison Chalk from a plant in Taiwan.) According to Matthew Hulet of Evolv Sports, which in addition to shoes also sells chalk, most of the chalk on the market comes from a handful of suppliers in China.
In fact, China produces 70 percent of the world’s magnesite. Most of that production—both mining and processing—is concentrated in a small corner of Liaoning, a hilly industrial province in northeast China between Beijing and North Korea. Here, gritty factories dot the landscape, and the cities lack the luster of the larger metropolises to the west and south. Yet, somehow, a white mineral from the bowels of this unassuming region has found its way onto rock faces all over the world.
A handful of mining and processing companies—like the “China Metallurgical Import and Export Liaoning Magnesite Company”—in Liaoning produce the magnesite. White smears run for miles up and down the mountains and hills surrounding cities like Haicheng, in southeastern Liaoning, blanketing buildings in the underlying valleys, giving the appearance of a ski resort. But it’s not snow—it’s magnesium carbonate dust, a result of both the mining process and poor filtration of airborne particles during the calcination, or heating, process.

“Three to four years ago, there was a protest in Haicheng about the pollution of magnesite plants,” says Tianyi Zhang, a student at New York University who grew up near the mining region. “Some plants were built right beside the Haicheng suburban residential area. The residents complained about the terrible smell of magnesite gases.” But the biggest problem with the mines is the dust. “Once the harmful dust drops on the ground, it gathers and forms a hard shell,” says Zhang of the crust of hydromagnesite—caked-up chalk dust that has been exposed to water. And that dust has a huge impact on the environment and local people.
De-Hui Zeng, an ecologist at the Chinese Academy of Sciences in Liaoning, has spent years cataloging the environmental impacts of his province’s magnesite plants. His samples from the land surrounding the mines and factories have implicated magnesite mining in large-scale plant death, soil degradation, and reduced microbial activity. Due to what Zeng calls “underdeveloped techniques,” the dust “accumulates and migrates to the plants and soil, which directly destroys plants’ photosynthesis and respiration, and results in extremely worsened soil physicochemical properties.”
As Zeng wrote in a 2011 research paper, “Land reclamation in such mining areas has become a great challenge for environmental management and ecological restoration. Remediation measures have not been successful: The survival rates of tree plantations is poor, and the yield of the few crops that do survive is very low.”
But it’s not all bad news. While China often gets a bad rap for its lax environmental regulations, the country is working to limit pollution. “We have an operation in China, and there was a time back in the 1990s when there was virtually no environmental restriction. I mean, literally rivers caught on fire,” says Silver. “But China has stepped up. There’s no doubt about it.” In 2017, China shut down dozens of magnesite plants for violating environmental regulations as part of a multibillion-dollar campaign to clamp down on air pollution, and mining companies are implementing solutions—like installing better air-filtration systems—to address the dust. “It sounds crazy, but I would have serious doubts whether the EPA would do more than China to regulate new mining,” says Charles Harvey, a climber and environmental scientist at MIT.
And it’s not as if chalk is the only type of gear that has an environmental cost. “If it’s not grown, it’s mined,” says Kelleghan, and he’s right. From the aluminum in our biners to the rubber on our shoes, everything we use is derived from some upstream source of raw materials. All products come from somewhere, and that somewhere has likely experienced environmental impact as a result.
So what’s an eco-conscious climber to do? “As much as we want to be environmentally friendly, it’s an incredible conundrum,” says Kelleghan. But there are lessons to be drawn from understanding where your chalk comes from, namely being cognizant that the choices we make about what we buy have specific impacts. What was surprising to me in researching this story wasn’t just where the chalk comes from; it was the fact that some chalk suppliers didn’t seem to know either. As the supply-line distance from material extraction to consumer purchase grows, it’s more important that suppliers learn where their products come from, and share that information with their customers.
This doesn’t have to be bad for business. Some apparel companies, for example, publish the addresses of the factories that make their clothing. What if we held outdoor companies to a similar standard? Climbing has always been tied to environmental ethics, but if climbers want to expand that ethic beyond not trampling plants at the crag, then asking for transparency about our gear is a good place to start.
The next time you take a powder shower or tick up a boulder with aimers that could be seen from outer space, think about the resource you’re using, and how it got to you. There is a cost, an impact, and a whole unseen life in a simple block of chalk, something it would benefit us all to consider.