Klaus Lackner Is Pulling CO2 Out of Thin Air

Stopping global warming has long been an environmentalist’s fantasy. Not anymore.

Klaus Lackner Is Pulling CO2 Out of Thin Air
A better branch: Sprigs like this, made of a special resin, soak up carbon dioxide from the atmosphere. [Photo: Celine Grouard]

The first thing you notice about Klaus Lackner’s new laboratory at Arizona State University is how it’s littered with thin, white pieces of plastic. The stuff is everywhere—in large sheets crumpled on counters; in small strips stacked on lab benches; and in shreds attached to stiff wires, so as to resemble the boughs of an artificial Christmas tree. “Here, feel this,” says Lackner’s research partner, Allen Wright, holding out a fresh sheet. “It’s almost like leather.” He’s right, but it’s an odd, stiff, pale sort of leather—and, anyway, what is it good for? You wouldn’t make a baseball glove out of it.

Klaus Lackner The Arizona State scientist has pursued his dream for years, despite critics who say he’ll never be able to make air capture affordable.Photo: Jonathan Snyder

The three of us are gathered around a sealed glass chamber, about the size of a large terrarium, in the experimental hub of Lackner’s new endeavor, the Center for Negative Carbon Emissions. Inside the clear container is a large, leafy plant and another sample of his ubiquitous white plastic, this time formatted into what resembles a square foot of white shag carpet. A laptop nearby gets readings from a sensor that measures the CO2 inside the tank. Earlier in the day, this piece of shaggy plastic—a commercially available “anionic exchange” resin that Lackner and Wright discovered a few years ago—was left out on the lab bench, where it soaked up atmospheric CO2 from the circulating air. Here in the sealed glass box, it responds to a humid environment by giving off that CO2 and soaking up atmospheric moisture in its place. “You can see this climbing,” says Lackner, pointing to a graph on the laptop tracing a steeply ascending line of the parts per million (ppm) of CO2 molecules in the tank.

The takeaway is clear: The white resin material is very good at naturally absorbing CO2 in the air. Just as important, it is very good at spewing it out when you put it in a moist environment or give it a quick rinse of water. You could even collect and bottle the CO2 gas that gets released. The whole cycle could be repeated, ad infinitum: absorb CO2, rinse it off, collect it; absorb, rinse, collect.

There may be only a few hundred people on the planet who are actively involved in what is called direct air capture, or air capture for short. Those working in the field (and its benefactors, such as Bill Gates and Edgar Bronf­man Jr.) seem convinced that a broad deployment of air capture devices is necessary to limit the impacts of increasing levels of atmospheric CO2, which include a warmer climate, rising sea levels, lingering droughts, and threats to agriculture and ocean fisheries. Air capture entrepreneurs do champion the use of clean-energy technologies like wind and solar power, and efforts to capture smokestack emissions of gas and coal power plants. But they tend to believe that such technologies alone cannot get the world to a necessary level of zero-carbon emissions.

Actually, we’ve been relying for ages on machines that pull CO2 from the atmosphere, acting as a counterbalance to what we’ve spewed from cars, airplanes, and power plants. We call these machines trees. And we’ve long had so-called scrubbers to make life bearable on submarines and spaceships by chemically removing excess CO2 in the air. What’s interesting about Lackner and Wright’s technology, however, is that the plastic resin they discovered might be able to absorb enormous quantities of CO2 and help us sequester it underground, affordably. By Lackner’s calculation, each air capture device would be about 1,000 times more effective than a single tree. “There’s no question that it works,” he says. “Whether you can do it practically remains to be seen and proved.”


At the moment, at least three fledgling companies (Global Thermostat in Menlo Park, California; Carbon Engineering in Calgary, Alberta; and Climeworks in Zurich) aim to enter the commercial space within the next 12 to 24 months. Lackner is the pioneer and giant in this field: Wally Broecker, a Columbia scientist who coined the term “global warming” (in a 1975 article in the journal Science), calls Lackner “the most brilliant person I’ve ever dealt with.” But for now, Lackner will focus on creating a think tank that proves to the public the viability of air capture and helps jump-start a large commercial industry.

From 2004 to 2008, Lackner and Wright used startup funding to create an air capture prototype, but in the recession they failed to secure more venture capital. Lackner’s ideas may have been premature, back then. It seemed possible that the carbon problem would be addressed by international accords and the start of a rapid transition to clean energy. In the time since, there has been incremental progress on emissions (such as a recent deal between the U.S. and China), but CO2 levels in the atmosphere continue to climb. When Lackner started, global CO2 emissions were rising at 1.5 ppm a year. “Now it’s well above 2 ppm per year,” he says. “And it’s still accelerating. That clearly is not sustainable.” To arrest the worst impacts of climate change, Lackner points out, we’ll eventually have to go to zero emissions—or even figure out a way to go negative, so as to get the atmospheric carbon to, say, 350 ppm. At the moment, levels are at 401 ppm. The last time CO2 concentrations reached this mark, about 3 million years ago, oceans were at least 35 feet higher and camels lived above the Arctic Circle.

An air capture device faces several notable challenges: First, there’s the architecture. Lackner’s design has changed many times over the years, although right now he prefers to form the white resin into a honeycomb pattern—imagine thousands of straws stacked atop each other in a circular frame, with the desert wind blowing through the holes. When I visited ASU, the two men showed me a small prototype of their device in the lab. In size and design, it looks a bit like a collapsible window shade sealed in a box of clear acrylic. In several months, the design will be built to a larger scale, and in a year or two, predicts Lackner, there will be several full-size devices on the campus at ASU, collecting carbon as well as data. “You cannot drive down the price unless you actually do it,” Lackner notes. “I want to do it incrementally. Start small and be horribly inefficient. Admit it’s expensive and say, ‘This is our starting point.’ ”

The design is just one hurdle: You also need a plan for what to do with the collected CO2. The device itself will have to automatically move into—and out of—an enclosed environment once or twice a day (think of a garage door being raised and then lowered) so that CO2 can be rinsed out and trapped. Gauging potential market demand for the captured carbon is tricky. Greenhouses buy CO2 to boost plant growth, companies looking at the cultivation of algae for biofuels might use it, and CO2 can perhaps be used as a crucial ingredient to make synthetic fuels. The latter idea would be an attempt to “close” the carbon cycle: you burn synth-fuel in your car or airplane; the CO2 is emitted into the atmosphere and ultimately collected; and it is then reformatted into synth-fuel. The process repeats itself.


But the most likely fate for all the CO2 is to be pumped deep underground. That way, we can forget about it for 1,000 years and avoid the potential catastrophes of a much warmer climate. Lackner, in fact, doesn’t believe air capture will be a viable business until the world’s governments put a price or a penalty on carbon extraction. His vision is this: If a fossil-fuel company wants to take a ton of carbon out of the ground in the form of natural gas or oil, a surcharge on their product would have to pay for a ton to be collected, via air capture, and then sequestered back underground. In other words, those companies would have to pay to play.

Prototypes: Air capture is such an experimental technology that Lackner has tried myriad designs, such as this roll and swatch, with his magic white plastic.Photo: Jonathan Snyder

We seem miles away, as a society, from supporting such a carbon policy. That doesn’t worry Lackner. “Technologies simmer along before they are feasible,” he tells me. “That simmer can be short or long, but then they get traction, and from there to being huge is a couple of decades.” He goes through a litany of examples, each proving his case: cars, jets, television, personal computers, laptops, the Internet. “It takes a couple decades,” he repeats.

Of course, getting feasible means getting affordable—something that a panel of eminent American scientists and engineers believed was highly unlikely for air capture machines. They concluded that carbon might be captured and stored for anywhere from $600 per ton to upwards of $1,000 per ton. Lackner has rankled some colleagues with his steadfast belief that air capture can be done more cheaply. “I have been on record as saying that ultimately I think you can do this for $30 per ton,” Lackner says. He offers more examples, this time of fundamental products whose prices have plummeted over a reasonable time: solar power, artificial light, wind power.

Talking with Lackner tends to have a distorting effect; what at first seems highly unrealistic is, by his logic, perfectly reasonable, and he tends not to stop talking until he makes his case, even if it takes hours. Think of an air capture device as an automobile, he tells me. “It weighs about as much as a car; its complexity is not much more than a car. If you had 100 million of them you would, it turns out, collect 36 gigatons”—that is, 36 billion tons—“of CO2 a year, so that puts you right at the scale of our current emissions. We would have zero emissions if we could do that.” Lackner estimates the air capture industry would have to build 10 million units per year to maintain those levels. At the moment, the global auto industry produces about 85 million vehicles annually. And all told, there are now about 1 billion cars in the world. “So we are large on the scale of industries, but we are not prohibitively large,” he insists. Besides, he adds, “we are large because we are solving a large problem. Right?”