“You might say it’s against my self-interest to say it, but I think that, in the near term, talking about carbon removal is silly,” David Keith, the founder of Carbon Engineering, who teaches energy and public policy at Harvard, told me. “Because it almost certainly is cheaper to cut emissions now than to do large-scale carbon removal.” — New Yorker, Nov 2017
From The Guardian 4 Feb 2018
“Direct air capture is no substitute for using conventional CCS,” says Professor Jon Gibbins, head of BECCS. “Cutting emissions from existing sources at the scale of millions of tonnes a year, to stop the CO2 getting into the air in the first place, is the first priority. The best use for all negative emission technologies is to offset emissions that are happening now – paid for by the emitters, or by the fossil fuel suppliers. We need to get to net zero emissions before the sustainable CO2 emissions are used up. This is estimated at around 1,000bn tonnes, or around 20-30 years of global emissions based on current trends,” he says. “Having to go to net negative emissions is obviously unfair and might well prove an unfeasible burden for a future global society already burdened by climate change.”
The achilles heel of all negative emission technologies is cost. Government policy units assume that they will become economically viable, but the best hope of Carbon Engineering and other direct air extraction companies is to get the price down to $100 a tonne from the current $600. Even then, to remove just 1% of global emissions would cost around $400bn a year, and would need to be continued for ever. Storing the CO2 permanently would cost extra.
Critics say that these technologies are unfeasible. Not using the fossil fuel and not producing the emissions in the first place would be much cleverer than having to find end-of-pipe solutions, say Professor Kevin Anderson, deputy director of the Tyndall Centre for Climate Change Research, and Glen Peters, research director at the Centre for International Climate Research (Cicero) in Norway. In a recent article in the journal Science, the two climate scientists said they were not opposed to research on negative emission technologies, but thought the world should proceed on the premise that they will not work at scale. Not to do so, they said, would be a “moral hazard par excellence”.
It’s nothing much to look at, but the tangle of pipes, pumps, tanks, reactors, chimneys and ducts on a messy industrial estate outside the logging town of Squamish in western Canada could just provide the fix to stop the world tipping into runaway climate change and substitute dwindling supplies of conventional fuel.
The idea is grandiose yet simple: decarbonise the global economy by extracting global-warming carbon dioxide (CO2) straight from the air, using arrays of giant fans and patented chemical whizzery; and then use the gas to make clean, carbon-neutral synthetic diesel and petrol to drive the world’s ships, planes and trucks.
The hope is that the combination of direct air capture (DAC), water electrolysis and fuels synthesis used to produce liquid hydrocarbon fuels can be made to work at a global scale, for little more than it costs to extract and sell fossil fuel today. This would revolutionise the world’s transport industry, which emits nearly one-third of total climate-changing emissions. It would be the equivalent of mechanising photosynthesis.
The individual technologies may not be new, but their combination at an industrial scale would be groundbreaking. Carbon Engineering, the company set up in 2009 by leading geoengineer Keith, with money from Gates and Murray, has constructed a prototype plant, installed large fans, and has been extracting around one tonne of pure CO2 every day for a year. At present it is released back into the air.
But Carbon Engineering (CE) has just passed another milestone. Working with California energy company Greyrock, it has now begun directly synthesising a mixture of petrol and diesel, using only CO2 captured from the air and hydrogen split from water with clean electricity – a process they call Air to Fuels (A2F).
“A2F is a potentially game-changing technology, which if successfully scaled up will allow us to harness cheap, intermittent renewable electricity to drive synthesis of liquid fuels that are compatible with modern infrastructure and engines,” says Geoff Holmes of CE. “This offers an alternative to biofuels and a complement to electric vehicles in the effort to displace fossil fuels from transportation.”
Synthetic fuels have been made from CO2 and H2 before, on a small scale. “But,” Holmes adds, “we think our pilot plant is the first instance of Air to Fuels where all the equipment has large-scale industrial precedent, and thus gives real indication of commercial performance and viability, and leads directly to scale-up and deployment.”
The next step is to raise the money, scale up and then commercialise the process using low-carbon electricity like solar PV (photovoltaics). Company publicity envisages massive walls of extractor fans sited outside cities and on non-agricultural land, supplying CO2 for fuel synthesis, and eventually for direct sequestration.
“A2F is the future,” says Holmes, “because it needs 100 times less land and water than biofuels, and can be scaled up and sited anywhere. But for it to work, it will have to reduce costs to little more than it costs to extract oil today, and – even trickier – persuade countries to set a global carbon price.”
Meanwhile, 4,500 miles away, in a large blue shed on a small industrial estate in the South Yorkshire coalfield outside Sheffield, the UK Carbon Capture and Storage Research Centre (UKCCSRC) is experimenting with other ways to produce negative emissions.
The UKCCSRC is what remains of Britain’s official foray into carbon capture and storage (CCS), which David Cameron had backed strongly until 2015. £1bn was ringfenced for a competition between large companies to extract CO2 from coal and gas plants and then store it, possibly in old North Sea gas wells. But the plan unravelled as austerity bit, and the UK’s only running CCS pilot plant, at Ferrybridge power station, was abandoned.
The Sheffield laboratory is funded by £2.7m of government money and run by Sheffield University. It is researching different fuels, temperatures, solvents and heating speeds to best capture the CO2for the next generation of CCS plants, and is capturing 50 tonnes of CO2 a year. And because Britain is phasing out coal power stations, the focus is on achieving negative emissions by removing and storing CO2 emitted from biomass plants, which burn pulverised wood. As the wood has already absorbed carbon while it grows, it is more or less carbon-neutral when burned. If linked to a carbon capture plant, it theoretically removes carbon from the atmosphere.
Known as BECCS (bioenergy with carbon capture and storage), this negative emissions technology is seen as vital if the UK is to meet its long-term climate target of an 80% cut in emissions at 1990 levels by 2050, according to UKCCSRC director Professor Jon Gibbins. The plan, he says, is to capture emissions from clusters of major industries, such as refineries and steelworks in places like Teesside, to reduce the costs of transporting and storing it underground.
“Direct air capture is no substitute for using conventional CCS,” says Gibbins. “Cutting emissions from existing sources at the scale of millions of tonnes a year, to stop the CO2 getting into the air in the first place, is the first priority.
“The best use for all negative emission technologies is to offset emissions that are happening now – paid for by the emitters, or by the fossil fuel suppliers. We need to get to net zero emissions before the sustainable CO2 emissions are used up. This is estimated at around 1,000bn tonnes, or around 20-30 years of global emissions based on current trends,” he says. “Having to go to net negative emissions is obviously unfair and might well prove an unfeasible burden for a future global society already burdened by climate change.”
The challenge is daunting. Worldwide manmade emissions must be brought to “net zero” no later than 2090, says the UN’s climate body, the Intergovernmental Panel on Climate Change (IPCC). That means balancing the amount of carbon released by humans with an equivalent amount sequestered or offset, or buying enough carbon credits to make up the difference.
But that will not be enough. To avoid runaway climate change, emissions must then become “net negative”, with more carbon being removed than emitted. Many countries, including the UK, assume that negative emissions will be deployed at a large scale. But only a handful of CCS and pilot negative-emission plants are running anywhere in the world, and debate still rages over which, if any, technologies should be employed. (A prize of $25m put up by Richard Branson in 2007 to challenge innovators to find a commercially viable way to remove at least 1bn tonnes of atmospheric CO2 a year for 10 years, and keep it out, has still not been claimed – possibly because the public is uncertain about geoengineering.)
The achilles heel of all negative emission technologies is cost. Government policy units assume that they will become economically viable, but the best hope of Carbon Engineering and other direct air extraction companies is to get the price down to $100 a tonne from the current $600. Even then, to remove just 1% of global emissions would cost around $400bn a year, and would need to be continued for ever. Storing the CO2 permanently would cost extra. Critics say that these technologies are unfeasible. Not using the fossil fuel and not producing the emissions in the first place would be much cleverer than having to find end-of-pipe solutions, say Professor Kevin Anderson, deputy director of the Tyndall Centre for Climate Change Research, and Glen Peters, research director at the Centre for International Climate Research (Cicero) in Norway.
In a recent article in the journal Science, the two climate scientists said they were not opposed to research on negative emission technologies, but thought the world should proceed on the premise that they will not work at scale. Not to do so, they said, would be a “moral hazard par excellence”.
Kris Milkowski, business development manager at the UKCCSRC, says: “Negative emissions technology is unavoidable and here to stay. We are simply not moving [to cut emissions] fast enough. If we had an endless pile of money, we could potentially go totally renewable energy. But that transition cannot happen overnight. This, I fear, is the only large-scale solution.”
Australian firm unveils plan to convert carbon emissions into ‘green’ concrete: Initiative to convert CO2 into solid carbonates aims to produce building materials on commercial scale by 2020
The launch will include a demonstration of the hour-long process bonding CO2 – stored in large cylinders at one end of the warehouse – with crushed serpentinite from the nearby Orica Kooragang Island operation, permanently converting it into solid carbonates.
By 2020 MCI hopes to be producing 20,000 to 50,000 tonnes of the bonded material for building companies, and said it anticipates the process will be economically viable even without a high carbon price.
“There is a big demand among consumers for green building products,” said Marcus Dawe, chief executive of MCI.
“The interest around the carbon brick has been extraordinary, but we’re going beyond that.”
In May the federal government said it would lift restrictions on the Clean Energy Finance Corporation to allow it to invest in carbon capture technology.
Similar initiatives around the world include a Canadian company making synthetic gasoline out of CO2 and hydrogen gas, and a US company manufacturing plastic products from methane gas.
Dawe said serpentinite was a readily available “feedstock” to absorb CO2, found around the world.
“Nowhere in the world had anyone scaled up enough to create enough material to give to manufacturers, to experiment and test them and find out what products they can make from them,” he said.
“This is all about getting them to a scale and getting them as economical as we can.”
He said a decade of research and development had worked towards reducing the cost of carbonation, but conceded there were environmental concerns with mining serpentinite.
“As much as possible we want to make this an environmental solution,” he said. “It really is the end state for carbon.”
Dawe said he saw the biggest potential for the process in the four billion tonnes of cement made around the world each year.
However environmental scientists and former chief climate commissioner, Tim Flannery, said there was already an acceptable substitution – fly ash and bottom ash from coal fired power stations – to make cement.
“I think it’s more likely we’ll be mining that to make negative carbon concrete and cement,” he said.
“One of the big problems is the coal-fired power stations charge people to take their waste away. Under a different regime you could be encouraging the uptake of that.”
Flannery also noted the energy cost of mining and transporting serpentinite, and said the cost of building and operating renewable power sources would soon be cheaper than running a coal-fired power station.
Prof Peter Cook, geologist and professorial fellow at the University of Melbourne, said the technology was a viable process and would be a contribution to reducing carbon emissions, but the difficulty was in the scale required.
“We need to be realistic about it, it’s not going to be the solution to the problem of global warming and climate change,” he said.
“I’m sure it will work chemically, and they’ve shown that it does. The issues is the extent to which you can deploy it.”
He said he was not diminishing the “great” value in what MCI was doing.
“The difficulty is just the scale of the issue that we’re facing,” he said. “I think it’s one of these processes where you’ll be able to make money from it in the local area. The difficulty is, for instance we’re getting 36bn tonnes of CO2 per annum from our use of fossil fuel. It’s important to keep that sort of number in mind when you think about the scale of the thing.”
Taking carbon out of the atmosphere will be crucial if we are to slow the progress of climate change. As technologies to capture carbon improve, some are already thinking about what we will do with all that CO2.
Storage in geological formations underground is one option. Better yet, what if we could make useful stuff out of it, such as biofuels, plastics or building materials?
Several initiatives to explore such ideas are under way. Canadian company Carbon Engineering is combining captured CO2 with hydrogen gas to generate synthetic gasoline at its pilot plant north of Vancouver. And Newlight Technologies, based near Los Angeles, California, is using the greenhouse gas methane to manufacture plastic products such as mobile-phone cases and chairs.
Another project, starting this week, will research ways to turn CO2 into common building materials. A pilot plant at the University of Newcastle near Sydney, Australia, will test the commercial potential of mineral carbonation. This is a process that chemically binds CO2 with calcium- or magnesium-containing minerals to form stable materials. The plant will bind CO2 with crushed serpentinite rocks to create magnesium carbonate, which can be used to produce building and construction materials such as cement, paving stones and plasterboard.
This carbonation process could be a way of “permanently and safely disposing of CO2, and making useful products in the process”, says Klaus Lackner, director of the Center for Negative Carbon Emissions at Arizona State University, Tempe, who pioneered laboratory studies of mineral carbonation.
The process happens naturally when rocks are exposed to CO2 in the air. This gradual weathering helped cut down CO2 in the ancient atmosphere to levels that were low enough for life to flourish, says Geoff Brent, senior scientist at Orica, an explosives manufacturer that will supply the pilot plant with CO2 – a by-product of its manufacture of ammonium nitrate.
But we don’t have millions of years to wait for geology to rid the atmosphere of excess carbon. “It’s about turning the natural process into a large-scale industrial process on our required time scale — which is extremely urgent,” says Brent.
There are several challenges in achieving this. Mining for serpentinite is itself energy-intensive and damaging to the environment. But Brent says an advantage is that the rock is one of the most common on Earth, and carbonation plants could be built near mining areas.
Another objection is that the carbonisation process still costs too much, whereas simply storing CO2 underground would be cheaper and require less energy.
However, Brent says that suitable underground repositories are hard to find and that carbon dioxide may escape back into the atmosphere even after being stored.
“Carbonation is more secure in the long term, because there is no danger of leakage and no need to maintain long gas pipelines and transportation infrastructure to move the CO2, since we will be obtaining it on-site,” says Brent.
And if the chemical reactions could be sped up and maintained with less heat, carbonation could become commercially competitive with underground injection storage of CO2.
“The whole point of the project is to get the price down low enough,” says Marcus Dawe, CEO of Mineral Carbonation International, the group coordinating the effort. “It is all about how we can make this economical.”
Dawe and his team are optimistic that they will make progress by the end of their initial 18-month project period, but whether their trials yield anything that can be scaled up on a meaningful level remains to be seen.
For mineral carbonation to take off, there will need to be a higher price on carbon, says Dawe, because right now “nothing is more economical than putting CO2 in the air”.
He is looking to China as one place where large-scale mineral carbonation might eventually take off. The country is developing a carbon-trading system that is expected to go into effect next year, and is also scrambling to find ways to cut emissions causing its massive urban air-pollution problem, says Dawe. https://www.newscientist.com/article/2082112-pilot-plant-to-turn-co2-into-house-parts-and-paving-stones/
JOHN LEHMANN/THE GLOBE AND MAIL
Could this plant hold the key to generating fuel from CO2 emissions?
Recapturing carbon from the atmosphere is one thing, but a Canadian company wants to go one step further by turning that carbon into fuel. In the process, it hopes to transform the fight against climate change, reports Ivan Semeniuk IVAN SEMENIUK
In the aftermath of the Paris climate agreement, those wondering how the world is going to seriously reduce and even reverse the flow of carbon dioxide into the atmosphere may find a key part of the answer taking shape on a rain-soaked parcel of industrial land in Squamish, B.C.
Sandwiched between towering cliffs and a dramatic coastline 50 kilometres north of Vancouver, the site is home to a small pilot plant where engineers are busy pulling CO2 out of the air so it can be stored or turned into a fuel that displaces conventional gasoline.
The idea amounts to a surprisingly simple but potentially game-changing way of getting at the climate problem. Around the world, temperatures and sea levels are rising because we’re burning too much carbon. The Squamish project is demonstrating a new way to unburn it.
There is no magic to removing carbon dioxide from air. It’s a feat that is performed routinely on submarines and spacecraft – places where the air supply is limited and occupants would suffocate if CO2 were allowed to build up. But the goal for Mr. Corless and his team is to separate CO2 from air using a method that can be scaled up to make a difference to the global climate system.
The strategy is known as direct air capture, and Carbon Engineering is one of a handful of companies in the world working to make it commercially viable. Since carbon dioxide concentration in the atmosphere is the same everywhere, a direct air capture facility could, in principle, be set up anywhere. The company settled on Squamish for its prototype because the land was available and engineering firms used to dealing with the chemical industry were close at hand.
Of course, one prototype plant won’t save the planet, but the facility is attracting global attention because it may prove especially useful for solving a key piece of the world’s carbon conundrum: the heavy-transportation sector.
‘Not a science project’
In the future, our cars may all run on battery power, and perhaps we’ll charge them up with electricity generated from renewable sources of energy. But even in such a world, few expect that trucks, trains, airplanes and ships are going to run that way. Unlike cars, heavy vehicles will still need fuel, such as gasoline or diesel, that is energy-dense and easy to carry.
Today, that fuel accounts for a big slice of the world’s greenhouse-gas emissions. Carbon Engineering aims to suck it out of the air rather than the ground. If the idea succeeds, it could divert a major contributor to climate change.
“What we’re doing is opening up, in a more serious way, a pathway to synthetic fuels from air,” says David Keith, the former University of Calgary physicist who is the company’s founder and executive chairman. “That’s something that people get excited about.”
Dr. Keith, now a faculty member at Harvard University, is better known for his work in geoengineering. As a scientist, he thinks about ways of tinkering with the planet on a grand scale to alleviate the effects of global warming. But the pilot plant in Squamish is “not a science project,” he emphasizes. It’s taking something that experts all agree is doable, and figuring out how to do it at a cost that is relevant to industry.
The challenge clearly preoccupies the tall, lean physicist – a pragmatist once identified by Time magazine as a “hero of the environment.” He has spent more than 25 years grappling with climate change as an intellectual problem, but is most enthusiastic when talking about turning ideas into nuts-and-bolts solutions.
He is not alone in his enthusiasm. Bill Gates, who made headlines in Paris with his Breakthrough Energy Coalition of high-profile entrepreneurs, is Carbon Engineering’s largest private investor. Federal dollars have also helped to get the Squamish project up and running over the past year. The plant, which cost $8-million to build, is also the only Canadian finalist for the Virgin Earth award, a $25-million (U.S.) prize set up by Richard Branson to promote the development of sustainable ways to remove greenhouse gases from the atmosphere.
While the business case for the project is currently focused on heavy transportation, the technology that Carbon Engineering has pioneered carries broader implications for the economics of climate change. By vacuuming carbon dioxide out of the air – something the world may need to do in earnest one day, in order to avoid the worst-case scenarios associated with global warming – the plant has effectively put a cost ceiling on what it would take to de-carbonize any industry in the world. If the day comes when companies must clean up the carbon they release, it’s to their advantage to find ways of doing it more cheaply than Carbon Engineering can do it for them.
“The simple fact that [the Squamish facility] is there will drive progress forward,” says Klaus Lackner, director of the Center for Negative Carbon Emissions at Arizona State University.
Dr. Lackner’s research involves looking for ways of removing CO2 using advanced materials that may prove more effective in the long run but are not yet ready for commercial application. Meanwhile, other competitors are developing ways to move into the marketplace. Among the most active is Climeworks of Zurich, which in November announced it will build a facility later this year to capture and supply carbon dioxide to a greenhouse operator to enhance vegetable growth. Another company, Global Thermostat, which operates a demonstration plant in Menlo Park, Calif., is also a pursuing direct air capture.
For Dr. Keith, the fact that others are pushing into the same arena is a positive sign. “It makes the case that this is a real thing,” he says.
Battling miniature smokestacks
In practice, direct air capture is quite different from the idea of capturing and storing the carbon emitted by power plants, a proposal that comes with its own set of challenges. Compared to power-plant emissions, carbon dioxide in the ambient air is much more diffuse and harder to concentrate. But when global sources are numerous and widely distributed – as they are in the transportation sector, where every tailpipe is a miniature smokestack – direct air capture is one of only two ways of getting the carbon back.
The other is growing plants. The biofuel industry is built around the idea that turning plants into ethanol creates a carbon-neutral fuel cycle. Critics of biofuels say that this ignores all the carbon released during growing and processing, not to mention the fact that all the land required to grow fuel in abundance might be better put to use growing food.
Carbon Engineering is testing the premise that, on a global scale, direct air capture makes more sense. Unlike others trying to do the same, it has deliberately avoided new technologies and chosen to leverage methods borrowed from other industries, linking them in a novel way.
On paper, the method is basic high-school chemistry: The Squamish plant sucks air into a device called a contactor, where it reacts with a chemical solution that absorbs about three-quarters of the air’s carbon, by volume. The liquid is then solidified into pellets that are cooked in a high-temperature furnace that releases the carbon again, but as pure CO2.
Construction of the Squamish facility began last spring and the initial steps of the process have been up and running since last summer. The plant has now produced several tonnes of pellets, some of which have been cooked down again. The last step, which makes the process cost-effective, involves recycling the chemicals used in the different reactions.
Once that final loop is closed, Mr. Corless says he expects the plant to capture about 1.5 tonnes of CO2 a day. The key technical goal is running the cycle enough times to get the data needed to optimize the process and move on to building a commercial-scale plant.
For now, the company is releasing the carbon dioxide it captures, but plans, by the end of 2016 to install a small fuel-synthesis operation at the back end of the plant. This facility would combine captured carbon dioxide with hydrogen gas to generate synthetic gasoline.
Dr. Keith estimates the process should be able to generate synthetic fuel for about $1 a litre. This is more than double the wholesale price for gasoline. But as governments intent on reining in climate change impose tougher standards that penalize carbon-intense fuel production, the expectation is that Carbon Engineering’s product will increasingly become more competitive, particularly for the kinds of vehicles that can’t easily switch to battery power. When that happens, there’s no real limit to how much of the transportation sector direct air capture can supply, says Dr. Keith.
“There are some ideas that are green but can never be big,” he says, but this “has the potential … to be huge.”
Ivan Semeniuk is The Globe and Mail’s science reporter.
Elizabeth Kolbert in the New Yorker, November 2017
Carbon Engineering, a company owned in part by Bill Gates, has its headquarters on a spit of land that juts into Howe Sound, an hour north of Vancouver. Until recently, the land was a toxic-waste site, and the company’s equipment occupies a long, barnlike building that, for many years, was used to process contaminated water. The offices, inherited from the business that poisoned the site, provide a spectacular view of Mt. Garibaldi, which rises to a snow-covered point, and of the Chief, a granite monolith that’s British Columbia’s answer to El Capitan. To protect the spit against rising sea levels, the local government is planning to cover it with a layer of fill six feet deep. When that’s done, it’s hoping to sell the site for luxury condos.
Adrian Corless, Carbon Engineering’s chief executive, who is fifty-one, is a compact man with dark hair, a square jaw, and a concerned expression. “Do you wear contacts?” he asked, as we were suiting up to enter the barnlike building. If so, I’d have to take extra precautions, because some of the chemicals used in the building could cause the lenses to liquefy and fuse to my eyes.
Inside, pipes snaked along the walls and overhead. The thrum of machinery made it hard to hear. In one corner, what looked like oversized beach bags were filled with what looked like white sand. This, Corless explained over the noise, was limestone—pellets of pure calcium carbonate.
Corless and his team are engaged in a project that falls somewhere between toxic-waste cleanup and alchemy. They’ve devised a process that allows them, in effect, to suck carbon dioxide out of the air. Every day at the plant, roughly a ton of CO2 that had previously floated over Mt. Garibaldi or the Chief is converted into calcium carbonate. The pellets are subsequently heated, and the gas is forced off, to be stored in cannisters. The calcium can then be recovered, and the process run through all over again.
“If we’re successful at building a business around carbon removal, these are trillion-dollar markets,” Corless told me.
This past April, the concentration of carbon dioxide in the atmosphere reached a record four hundred and ten parts per million. The amount of CO2 in the air now is probably greater than it’s been at any time since the mid-Pliocene, three and a half million years ago, when there was a lot less ice at the poles and sea levels were sixty feet higher. This year’s record will be surpassed next year, and next year’s the year after that. Even if every country fulfills the pledges made in the Paris climate accord—and the United States has said that it doesn’t intend to—carbon dioxide could soon reach levels that, it’s widely agreed, will lead to catastrophe, assuming it hasn’t already done so.
Carbon-dioxide removal is, potentially, a trillion-dollar enterprise because it offers a way not just to slow the rise in CO2 but to reverse it. The process is sometimes referred to as “negative emissions”: instead of adding carbon to the air, it subtracts it. Carbon-removal plants could be built anywhere, or everywhere. Construct enough of them and, in theory at least, CO2 emissions could continue unabated and still we could avert calamity. Depending on how you look at things, the technology represents either the ultimate insurance policy or the ultimate moral hazard.
Carbon Engineering is one of a half-dozen companies vying to prove that carbon removal is feasible. Others include Global Thermostat, which is based in New York, and Climeworks, based near Zurich. Most of these owe their origins to the ideas of a physicist named Klaus Lackner, who now works at Arizona State University, in Tempe, so on my way home from British Columbia I took a detour to visit him. It was July, and on the day I arrived the temperature in the city reached a hundred and twelve degrees. When I got to my hotel, one of the first things I noticed was a dead starling lying, feet up, in the parking lot. I wondered if it had died from heat exhaustion.
Lackner, who is sixty-five, grew up in Germany. He is tall and lanky, with a fringe of gray hair and a prominent forehead. I met him in his office at an institute he runs, the Center for Negative Carbon Emissions. The office was bare, except for a few New Yorker cartoons on the theme of nerd-dom, which, Lackner told me, his wife had cut out for him. In one, a couple of scientists stand in front of an enormous whiteboard covered in equations. “The math is right,” one of them says. “It’s just in poor taste.”
In the late nineteen-seventies, Lackner moved from Germany to California to study with George Zweig, one of the discoverers of quarks. A few years later, he got a job at Los Alamos National Laboratory. There, he worked on fusion. “Some of the work was classified,” he said, “some of it not.”
Fusion is the process that powers the stars and, closer to home, thermonuclear bombs. When Lackner was at Los Alamos, it was being touted as a solution to the world’s energy problem; if fusion could be harnessed, it could generate vast amounts of carbon-free power using isotopes of hydrogen. Lackner became convinced that a fusion reactor was, at a minimum, decades away. (Decades later, it’s generally agreed that a workable reactor is still decades away.) Meanwhile, the globe’s growing population would demand more and more energy, and this demand would be met, for the most part, with fossil fuels.
“I realized, probably earlier than most, that the claims of the demise of fossil fuels were greatly exaggerated,” Lackner told me. (In fact, fossil fuels currently provide about eighty per cent of the world’s energy. Proportionally, this figure hasn’t changed much since the mid-eighties, but, because global energy use has nearly doubled, the amount of coal, oil, and natural gas being burned today is almost two times greater.)
This same array could be put to use scrubbing carbon dioxide from the atmosphere. According to Lackner and Wendt, the power generated by a Nigeria-size solar farm would be enough to remove all the CO2 emitted by humans up to that point within five years. Ideally, the CO2 would be converted to rock, similar to the white sand produced by Carbon Engineering; enough would be created to cover Venezuela in a layer a foot and a half deep. (Where this rock would go the two did not specify.)
Lackner let the idea of the self-replicating machine slide, but he became more and more intrigued by carbon-dioxide removal, particularly by what’s become known as “direct air capture.”
“Sometimes by thinking through this extreme end point you learn a lot,” he said. He began giving talks and writing papers on the subject. Some scientists decided he was nuts, others that he was a visionary. “Klaus is, in fact, a genius,” Julio Friedmann, a former Principal Deputy Assistant Secretary of Energy and an expert on carbon management, told me.
In 2000, Lackner received a job offer from Columbia University. Once in New York, he pitched a plan for developing a carbon-sucking technology to Gary Comer, a founder of Lands’ End. Comer brought to the meeting his investment adviser, who quipped that Lackner wasn’t looking for venture capital so much as “adventure capital.” Nevertheless, Comer offered to put up five million dollars. The new company was called Global Research Technologies, or G.R.T. It got as far as building a small prototype, but just as it was looking for new investors the financial crisis hit.
“Our timing was exquisite,” Lackner told me. Unable to raise more funds, the company ceased operations. As the planet continued to warm, and carbon-dioxide levels continued to climb, Lackner came to believe that, unwittingly, humanity had already committed itself to negative emissions.
“I think that we’re in a very uncomfortable situation,” he said. “I would argue that if technologies to pull CO2 out of the environment fail then we’re in deep trouble.”
Lackner founded the Center for Negative Carbon Emissions at A.S.U. in 2014. Most of the equipment he dreams up is put together in a workshop a few blocks from his office. The day I was there, it was so hot outside that even the five-minute walk to the workshop required staging. Lackner delivered a short lecture on the dangers of dehydration and handed me a bottle of water.
In the workshop, an engineer was tinkering with what looked like the guts of a foldout couch. Where, in the living-room version, there would have been a mattress, in this one was an elaborate array of plastic ribbons. Embedded in each ribbon was a powder made from thousands upon thousands of tiny amber-colored beads. The beads, Lackner explained, could be purchased by the truckload; they were composed of a resin normally used in water treatment to remove chemicals like nitrates. More or less by accident, Lackner had discovered that the beads could be repurposed. Dry, they’d absorb carbon dioxide. Wet, they’d release it. The idea was to expose the ribbons to Arizona’s thirsty air, and then fold the device into a sealed container filled with water. The CO2 that had been captured by the powder in the dry phase would be released in the wet phase; it could then be piped out of the container, and the whole process re-started, the couch folding and unfolding over and over again.
Lackner has calculated that an apparatus the size of a semi trailer could remove a ton of carbon dioxide per day, or three hundred and sixty-five tons a year. The world’s cars, planes, refineries, and power plants now produce about thirty-six billion tons of CO2 annually, so, he told me, “if you built a hundred million trailer-size units you could actually keep up with current emissions.” He acknowledged that the figure sounded daunting. But, he noted, the iPhone has been around for only a decade or so, and there are now seven hundred million in use. “We are still very early in this game,” he said.
The way Lackner sees things, the key to avoiding “deep trouble” is thinking differently. “We need to change the paradigm,” he told me. Carbon dioxide should be regarded the same way we view other waste products, like sewage or garbage. We don’t expect people to stop producing waste. (“Rewarding people for going to the bathroom less would be nonsensical,” Lackner has observed.) At the same time, we don’t let them shit on the sidewalk or toss their empty yogurt containers into the street.
“If I were to tell you that the garbage I’m dumping in front of your house is twenty per cent less this year than it was last year, you would still think I’m doing something intolerable,” Lackner said.
One of the reasons we’ve made so little progress on climate change, he contends, is that the issue has acquired an ethical charge, which has polarized people. To the extent that emissions are seen as bad, emitters become guilty. “Such a moral stance makes virtually everyone a sinner, and makes hypocrites out of many who are concerned about climate change but still partake in the benefits of modernity,” he has written. Changing the paradigm, Lackner believes, will change the conversation. If CO2 is treated as just another form of waste, which has to be disposed of, then people can stop arguing about whether it’s a problem and finally start doing something.
Carbon dioxide was “discovered,” by a Scottish physician named Joseph Black, in 1754. A decade later, another Scotsman, James Watt, invented a more efficient steam engine, ushering in what is now called the age of industrialization but which future generations may dub the age of emissions. It is likely that by the end of the nineteenth century human activity had raised the average temperature of the earth by a tenth of a degree Celsius (or nearly two-tenths of a degree Fahrenheit).
As the world warmed, it started to change, first gradually and then suddenly. By now, the globe is at least one degree Celsius (1.8 degrees Fahrenheit) warmer than it was in Black’s day, and the consequences are becoming ever more apparent. Heat waves are hotter, rainstorms more intense, and droughts drier. The wildfire season is growing longer, and fires, like the ones that recently ravaged Northern California, more numerous. Sea levels are rising, and the rate of rise is accelerating. Higher sea levels exacerbated the damage from Hurricanes Harvey, Irma, and Maria, and higher water temperatures probably also made the storms more ferocious. “Harvey is what climate change looks like,” Eric Holthaus, a meteorologist turned columnist, recently wrote.
Meanwhile, still more warming is locked in. There’s so much inertia in the climate system, which is as vast as the earth itself, that the globe has yet to fully adjust to the hundreds of billions of tons of carbon dioxide that have been added to the atmosphere in the past few decades. It’s been calculated that to equilibrate to current CO2 levels the planet still needs to warm by half a degree. And every ten days another billion tons of carbon dioxide are released. Last month, the World Meteorological Organization announced that the concentration of carbon dioxide in the atmosphere jumped by a record amount in 2016.
No one can say exactly how warm the world can get before disaster—the inundation of low-lying cities, say, or the collapse of crucial ecosystems, like coral reefs—becomes inevitable. Officially, the threshold is two degrees Celsius (3.6 degrees Fahrenheit) above preindustrial levels. Virtually every nation signed on to this figure at a round of climate negotiations held in Cancún in 2010.
Meeting in Paris in 2015, world leaders decided that the two-degree threshold was too high; the stated aim of the climate accord is to hold “the increase in the global average temperature to well below 2°C” and to try to limit it to 1.5°C. Since the planet has already warmed by one degree and, for all practical purposes, is committed to another half a degree, it would seem impossible to meet the latter goal and nearly impossible to meet the former. And it is nearly impossible, unless the world switches course and instead of just adding CO2 to the atmosphere also starts to remove it.
The extent to which the world is counting on negative emissions is documented by the latest report of the Intergovernmental Panel on Climate Change, which was published the year before Paris. To peer into the future, the IPCC relies on computer models that represent the world’s energy and climate systems as a tangle of equations, and which can be programmed to play out different “scenarios.” Most of the scenarios involve temperature increases of two, three, or even four degrees Celsius—up to just over seven degrees Fahrenheit—by the end of this century. (In a recent paper in the Proceedings of the National Academy of Sciences, two climate scientists—Yangyang Xu, of Texas A. & M., and Veerabhadran Ramanathan, of the Scripps Institution of Oceanography—proposed that warming greater than three degrees Celsius be designated as “catastrophic” and warming greater than five degrees as “unknown??” The “unknown??” designation, they wrote, comes “with the understanding that changes of this magnitude, not experienced in the last 20+ million years, pose existential threats to a majority of the population.”)
When the IPCC went looking for ways to hold the temperature increase under two degrees Celsius, it found the math punishing. Global emissions would have to fall rapidly and dramatically—pretty much down to zero by the middle of this century. (This would entail, among other things, replacing most of the world’s power plants, revamping its agricultural systems, and eliminating gasoline-powered vehicles, all within the next few decades.) Alternatively, humanity could, in effect, go into hock. It could allow CO2 levels temporarily to exceed the two-degree threshold—a situation that’s become known as “overshoot”—and then, via negative emissions, pull the excess CO2 out of the air.
The IPCC considered more than a thousand possible scenarios. Of these, only a hundred and sixteen limit warming to below two degrees, and of these a hundred and eight involve negative emissions. In many below-two-degree scenarios, the quantity of negative emissions called for reaches the same order of magnitude as the “positive” emissions being produced today.
“The volumes are outright crazy,” Oliver Geden, the head of the E.U. research division of the German Institute for International and Security Affairs, told me. Lackner said, “I think what the IPCC really is saying is ‘We tried lots and lots of scenarios, and, of the scenarios which stayed safe, virtually every one needed some magic touch of a negative emissions. If we didn’t do that, we ran into a brick wall.’ ”
Pursued on the scale envisioned by the IPCC, carbon-dioxide removal would yield at first tens of billions and soon hundreds of billions of tons of CO2, all of which would have to be dealt with. This represents its own supersized challenge. CO2 can be combined with calcium to produce limestone, as it is in the process at Carbon Engineering (and in Lackner’s self-replicating-machine scheme). But the necessary form of calcium isn’t readily available, and producing it generally yields CO2, a self-defeating prospect. An alternative is to shove the carbon back where it came from, deep underground.
“If you are storing CO2 and your only purpose is storage, then you’re looking for a package of certain types of rock,” Sallie Greenberg, the associate director for energy, research, and development at the Illinois State Geological Survey, told me. It was a bright summer day, and we were driving through the cornfields of Illinois’s midsection. A mile below us was a rock formation known as the Eau Claire Shale, and below that a formation known as the Mt. Simon Sandstone. Together with a team of drillers, engineers, and geoscientists, Greenberg has spent the past decade injecting carbon dioxide into this rock “package” and studying the outcome. When I’d proposed over the phone that she show me the project, in Decatur, she’d agreed, though not without hesitation.
“It isn’t sexy,” she’d warned me. “It’s a wellhead.”
Our first stop was a building shaped like a ski chalet. This was the National Sequestration Education Center, a joint venture of the Illinois geological survey, the U.S. Department of Energy, and Richland Community College. Inside were classrooms, occupied that morning by kids making lanyards, and displays aimed at illuminating the very dark world of carbon storage. One display was a sort of oversized barber pole, nine feet tall and decorated in bands of tan and brown, representing the various rock layers beneath us. A long arrow on the side of the pole indicated how many had been drilled through for Greenberg’s carbon-storage project; it pointed down, through the New Albany Shale, the Maquoketa Shale, and so on, all the way to the floor.
The center’s director, David Larrick, was on hand to serve as a guide. In addition to schoolkids, he said, the center hosted lots of community groups, like Kiwanis clubs. “This is very effective as a visual,” he told me, gesturing toward the pole. Sometimes farmers were concerned about the impact that the project could have on their water supply. The pole showed that the CO2 was being injected more than a mile below their wells.
“We have had overwhelmingly positive support,” he said. While Greenberg and Larrick chatted, I wandered off to play an educational video game. A cartoon figure in a hard hat appeared on the screen to offer factoids such as “The most efficient method of transport of CO2 is by pipeline.”
“Transport CO2 to earn points!” the cartoon man exhorted.
After touring the center’s garden, which featured grasses, like big bluestem, that would have been found in the area before it was plowed into cornfields, Greenberg and I drove on. Soon we passed through the gates of an enormous Archer Daniels Midland plant, which rose up out of the fields like a small city.
Greenberg explained that the project we were visiting was one of seven funded by the Department of Energy to learn whether carbon injected underground would stay there. In the earliest stage of the project, initiated under President George W. Bush, Greenberg and her colleagues sifted through geological records to find an appropriate test site. What they were seeking was similar to what oil drillers look for—porous stone capped by a layer of impermeable rock—only they were looking not to extract fossil fuels but, in a manner of speaking, to stuff them back in. The next step was locating a ready source of carbon dioxide. This is where A.D.M. came in; the plant converts corn into ethanol, and one of the by-products of this process is almost pure CO2. In a later stage of the project, during the Obama Administration, a million tons of carbon dioxide from the plant were pumped underground. Rigorous monitoring has shown that, so far, the CO2 has stayed put.
We stopped to pick up hard hats and went to see some of the monitoring equipment, which was being serviced by two engineers, Nick Malkewicz and Jim Kirksey. It was now lunchtime, so we made another detour, to a local barbecue place. Finally, Greenberg and I and the two men got to the injection site. It was, indeed, not sexy—just a bunch of pipes and valves sticking out of the dirt. I asked about the future of carbon storage.
“I think the technology’s there and it’s absolutely viable,” Malkewicz said. “It’s just a question of whether people want to do it or not. It’s kind of an obvious thing.”
“We know we can meet the objective of storing CO2,” Greenberg added. “Like Nick said, it’s just a matter of whether or not as a society we’re going to do it.”
When work began on the Decatur project, in 2003, few people besides Klaus Lackner were thinking about sucking CO2 from the air. Instead, the goal was to demonstrate the feasibility of an only slightly less revolutionary technology—carbon capture and storage (or, as it is sometimes referred to, carbon capture and sequestration).
With C.C.S., the CO2 produced at a power station or a steel mill or a cement plant is drawn off before it has a chance to disperse into the atmosphere. (This is called “post-combustion capture.”) The gas, under very high pressure, is then injected into the appropriate package of rock, where it is supposed to remain permanently. The process has become popularly—and euphemistically—known as “clean coal,” because, if all goes according to plan, a plant equipped with C.C.S. produces only a fraction of the emissions of a conventional coal-fired plant.
Over the years, both Republicans and Democrats have touted clean coal as a way to save mining jobs and protect the environment. The coal industry has also, nominally at least, embraced the technology; one industry-sponsored group calls itself the American Coalition for Clean Coal Electricity. Donald Trump, too, has talked up clean coal, even if he doesn’t seem to quite understand what the term means. “We’re going to have clean coal, really clean coal,” he said in March.
Currently, only one power plant in the U.S., the Petra Nova plant, near Houston, uses post-combustion carbon capture on a large scale. Plans for other plants to showcase the technology have been scrapped, including, most recently, the Kemper County plant, in Mississippi. This past June, the plant’s owner, Southern Company, announced that it was changing tacks. Instead of burning coal and capturing the carbon, the plant would burn natural gas and release the CO2.
Experts I spoke to said that the main reason C.C.S. hasn’t caught on is that there’s no inducement to use it. Capturing the CO2 from a smokestack consumes a lot of power—up to twenty-five per cent of the total produced at a typical coal-burning plant. And this, of course, translates into costs. What company is going to assume such costs when it can dump CO2 into the air for free?
“If you’re running a steel mill or a power plant and you’re putting the CO2 into the atmosphere, people might say, ‘Why aren’t you using carbon capture and storage?’ ” Howard Herzog, an engineer at M.I.T. who for many years ran a research program on CCS, told me. “And you say, ‘What’s my financial incentive? No one’s saying I can’t put it in the atmosphere.’ In fact, we’ve gone backwards in terms of sending signals that you’re going to have to restrict it.”
But, although C.C.S. has stalled in practice, it has become ever more essential on paper. Practically all below-two-degree warming scenarios assume that it will be widely deployed. And even this isn’t enough. To avoid catastrophe, most models rely on a yet to be realized variation of C.C.S., known as beccs.
Beccs, which stands for “bio-energy with carbon capture and storage,” takes advantage of the original form of carbon engineering: photosynthesis. Trees and grasses and shrubs, as they grow, soak up CO2 from the air. (Replanting forests is a low-tech form of carbon removal.) Later, when the plants rot or are combusted, the carbon they have absorbed is released back into the atmosphere. If a power station were to burn wood, say, or cornstalks, and use C.C.S. to sequester the resulting CO2, this cycle would be broken. Carbon would be sucked from the air by the green plants and then forced underground. beccs represents a way to generate negative emissions and, at the same time, electricity. The arrangement, at least as far as the models are concerned, could hardly be more convenient.
“Beccs is unique in that it removes carbon and produces energy,” Glen Peters, a senior researcher at the Center for International Climate Research, in Oslo, told me. “So the more you consume the more you remove.” He went on, “In a sense, it’s a dream technology. It’s solving one problem while solving the other problem. What more could you want?”
The Center for Carbon Removal doesn’t really have an office; it operates out of a co-working space in downtown Oakland. On the day I visited, not long after my trip to Decatur, someone had recently stopped at Trader Joe’s, and much of the center’s limited real estate was taken up by tubs of treats.
“Open anything you want,” the center’s executive director, Noah Deich, urged me, with a wave of his hand.
Deich, who is thirty-one, has a broad face, a brown beard, and a knowing sort of earnestness. After graduating from the University of Virginia, in 2009, he went to work for a consulting firm in Washington, D.C., that was advising power companies about how to prepare for a time when they’d no longer be able to release carbon into the atmosphere cost-free. It was the start of the Obama Administration, and that time seemed imminent. The House of Representatives had recently approved legislation to limit emissions. But the bill later died in the Senate, and, as Deich put it, “It’s no fun to model the impacts of climate policies nobody believes are going to happen.” He switched consulting firms, then headed to business school, at the University of California, Berkeley.
“I came into school with this vision of working for a clean-tech startup,” he told me. “But I also had this idea floating around in the back of my head that we’re moving too slowly to actually stop emissions in time. So what do we do with all the carbon that’s in the air?” He started talking to scientists and policy experts at Berkeley. What he learned shocked him.
“People told me, ‘The models show this major need for negative emissions,’ ” he recalled. “ ‘But we don’t really know how to do that, nor is anyone really thinking about it.’ I was someone who’d been in the business and policy world, and I was, like, wait a minute—what?”
Business school taught Deich to think in terms of case studies. One that seemed to him relevant was solar power. Photovoltaic cells have been around since the nineteen-fifties, but for decades they were prohibitively expensive. Then the price started to drop, which increased demand, which led to further price drops, to the point where today, in many parts of the world, the cost of solar power is competitive with the cost of power from new coal plants.
“And the reason that it’s now competitive is that governments decided to do lots and lots of research,” Deich said. “And some countries, like Germany, decided to pay a lot for solar, to create a first market. And China paid a lot to manufacture the stuff, and states in the U.S. said, ‘You must consume renewable energy,’ and then consumers said, ‘Hey, how can I buy renewable energy?’ ”
As far as he could see, none of this—neither the research nor the creation of first markets nor the spurring of consumer demand—was being done for carbon removal, so he decided to try to change that. Together with a Berkeley undergraduate, Giana Amador, he founded the center in 2015, with a hundred-and-fifty-thousand-dollar grant from the university. It now has an annual budget of about a million dollars, raised from private donors and foundations, and a staff of seven. Deich described it as a “think-and-do tank.”
“We’re trying to figure out: how do we actually get this on the agenda?” he said.
A compelling reason for putting carbon removal on “the agenda” is that we are already counting on it. Negative emissions are built into the I.P.C.C. scenarios and the climate agreements that rest on them.
But everyone I spoke with, including the most fervent advocates for carbon removal, stressed the huge challenges of the work, some of them technological, others political and economic. Done on a scale significant enough to make a difference, direct air capture of the sort pursued by Carbon Engineering, in British Columbia, would require an enormous infrastructure, as well as huge supplies of power. (Because CO2 is more dilute in the air than it is in the exhaust of a power plant, direct air capture demands even more energy than C.C.S.) The power would have to be generated emissions-free, or the whole enterprise wouldn’t make much sense.
“You might say it’s against my self-interest to say it, but I think that, in the near term, talking about carbon removal is silly,” David Keith, the founder of Carbon Engineering, who teaches energy and public policy at Harvard, told me. “Because it almost certainly is cheaper to cut emissions now than to do large-scale carbon removal.”
Beccs doesn’t make big energy demands; instead, it requires vast tracts of arable land. Much of this land would, presumably, have to be diverted from food production, and at a time when the global population—and therefore global food demand—is projected to be growing. (It’s estimated that to do beccs on the scale envisioned by some below-two-degrees scenarios would require an area larger than India.) Two researchers in Britain, Naomi Vaughan and Clair Gough, who recently conducted a workshop on beccs, concluded that “assumptions regarding the extent of bioenergy deployment that is possible” are generally “unrealistic.”
For these reasons, many experts argue that even talking (or writing articles) about negative emissions is dangerous. Such talk fosters the impression that it’s possible to put off action and still avoid a crisis, when it is far more likely that continued inaction will just produce a larger crisis. In “The Trouble with Negative Emissions,” an essay that ran last year in Science, Kevin Anderson, of the Tyndall Centre for Climate Change Research, in England, and Glen Peters, of the climate-research center in Oslo, described negative-emissions technologies as a “high-stakes gamble” and relying on them as a “moral hazard par excellence.”
We should, they wrote, “proceed on the premise that they will not work at scale.”
Others counter that the moment for fretting about the hazards of negative emissions—moral or otherwise—has passed.
“The punch line is, it doesn’t matter,” Julio Friedmann, the former Principal Deputy Assistant Energy Secretary, told me. “We actually need to do direct air capture, so we need to create technologies that do that. Whether it’s smart or not, whether it’s optimized or not, whether it’s the lowest-cost pathway or not, we know we need to do it.”
“If you tell me that we don’t know whether our stuff will work, I will admit that is true,” Klaus Lackner said. “But I also would argue that nobody else has a good option.”
One of the peculiarities of climate discussions is that the strongest argument for any given strategy is usually based on the hopelessness of the alternatives: this approach must work, because clearly the others aren’t going to. This sort of reasoning rests on a fragile premise—what might be called solution bias. There has to be an answer out there somewhere, since the contrary is too horrible to contemplate.
Early last month, the Trump Administration announced its intention to repeal the Clean Power Plan, a set of rules aimed at cutting power plants’ emissions. The plan, which had been approved by the Obama Administration, was eminently achievable. Still, according to the current Administration, the cuts were too onerous. The repeal of the plan is likely to result in hundreds of millions of tons of additional emissions.
A few weeks later, the United Nations Environment Programme released its annual Emissions Gap Report. The report labelled the difference between the emissions reductions needed to avoid dangerous climate change and those which countries have pledged to achieve as “alarmingly high.” For the first time, this year’s report contains a chapter on negative emissions. “In order to achieve the goals of the Paris Agreement,” it notes, “carbon dioxide removal is likely a necessary step.”
As a technology of last resort, carbon removal is, almost by its nature, paradoxical. It has become vital without necessarily being viable. It may be impossible to manage and it may also be impossible to manage without. ♦
While technologies are being developed that can remove carbon dioxide from the air, they aren’t yet feasible on the scale needed to slow global warming, Europe’s national science academies warn in a new report.
A wide array of technologies—from land management to ocean fertilization to capturing carbon dioxide from the air and storing it—are in various stages of testing and use, but according to the European Academies’ Science Advisory Council, climate scientists and policymakers are being “seriously over-optimistic” about how much these approaches can help deal with the global warming crisis.
In recent years, climate experts have suggested that it’s not enough to just decrease the amount of greenhouse gases emitted. To avoid more than 2 degrees Celsius of global warming this century, they say, net emissions will have to fall to zero within a few decades, and it’s worth considering “negative emissions”—steps that subtract pollution from the atmosphere to offset what is being added.
But despite the appeal of that notion, which in theory allows the world to overshoot its emissions budget for a while and make up the difference later, the new report warns against banking on it.
“These technologies offer only limited realistic potential to remove carbon from the atmosphere, and not at the scale envisaged in some climate scenarios,” wrote the report’s authors, a group of experts representing the national science academies of the European Union member states, Norway and Switzerland.
The global efforts to slow warming typically rely on two methods: enacting policies to drastically reduce greenhouse gas emissions and developing technologies that can remove CO2 from the atmosphere.
While the policy side of mitigating the crisis made great strides with the Paris climate agreement of 2015, on the negative emissions side, there are still more questions than answers.
That’s troubling, because most of the pathways laid out by the UN’s Intergovernmental Panel on Climate Change (IPCC) rely on deploying negative emissions approaches by the middle of this century.
The inclination to think that technological breakthroughs will eventually save the day may be dangerous, warns Thierry Courvoisier, president of the European Academies’ Science Advisory Council.
“It is no exaggeration to see responding to the real threats of climate change as a race against time: the longer action is delayed, the more acute and intractable the problem becomes,” he wrote in the report’s foreword. “If such technologies are seen as a potential fail-safe or backup measure, they could influence priorities on shorter-term mitigation strategies.”
But others say it’s also a mistake to rely wholly on emissions cuts, which are unlikely to come fast enough to avoid a crisis.
Klaus Lackner, the director of Center for Negative Carbon Emissions at Arizona State University, explains it with an analogy: The global emissions trajectory is like being in a car that’s careening toward a curve. Just taking your foot off the gas (slowing emissions) isn’t enough, Lackner says—you need to step on the brake, too, and remove some of what has already been emitted.
“I know that with that curve coming in front of us, we are going to hit the guardrail,” Lackner said. “My way of looking at it is not ‘can we avoid hitting it,’ but ‘can we avoid a rollover’.”
What’s Challenging These Technologies?
The EU scientists’ conclusion that negative emissions technologies represent more of a wish than a promise followed an exhaustive review of academic studies on each technology. The report examined seven technologies and weighed how likely each was to make a difference on global climate:
- Afforestation and reforestation: Simply put, more trees means less carbon in the atmosphere. But offsetting emissions from fossil fuels would require huge forests, competing with food production and posing other problems.
- Land management to increase carbon in soil: Changing agricultural practices to increase the carbon stored in soil could make a significant contribution, but these practices can be easily reversed if farming returns to more intensive methods.
- Bioenergy with carbon capture and storage: Burning trees or other crops instead of fossil fuels in power plants, then capturing the CO2 from the smokestacks and storing it underground, would require huge tracts of land and risky changes to ecosystems.
- Enhanced weathering: By adding minerals to oceans and soils, enhanced weathering is expected to be able to remove carbon, though on a smaller scale than the other technologies being explored. As of now, however, there are no projects to test the feasibility.
- Direct air capture and storage: When air flows past a direct capture system, the carbon dioxide is selectively removed. It’s then released as a concentrated stream for disposal or use. This technology is currently in operation on a small scale, but the size and cost of the equipment could get in the way of scaling it up.
- Ocean fertilization: Tiny plants in the ocean take up CO2, then die and sink to the ocean floor. Enhancing this process, such as by adding iron to stimulate phytoplankton growth, could have a substantial impact on atmospheric CO2 concentrations over several decades to centuries. But there are drawbacks, including risks from algal blooms and other ecological damage.
- Carbon capture and storage: This basically is a way to continue burning fossil fuels by capturing their greenhouse gases and storing them, keeping them out of the atmosphere. Technology and policy experts have been hoping to make it work for years. But so far, CCS has not proven affordable, and governments have been unwilling to pay for it on a large scale. A few projects are up and running, but many others have been cancelled.
That Doesn’t Mean Abandon the Work
The report’s authors aren’t suggesting that the technology should be abandoned—just that its limitations have to be fully understood. “In the event of mitigation failing to deliver a safe future operating space for humanity, failure of such technologies to deliver would then condemn humanity to a dangerously warming world,” the authors wrote.
Lackner said the high-stakes nature of the climate change battle are precisely why both mitigation and technology need to be pursued simultaneously.
“We have a demonstrated record of having not succeeded with mitigation alone,” he said. “We, at this point, have reached a point where even heroic efforts won’t get you there.”
He believes the most likely candidate is direct capture of carbon dioxidefrom air. “The reason the cost is high is because it’s new,” he said. “If you look at PV (photovoltaic solar energy), it’s 100 times cheaper now than in 1960.”
Peter Kelemen, a professor of earth and environmental science at Columbia University, said he favors an “all of the above” approach. “It is a mistake to wait for complete implementation of other mitigation approaches, since meanwhile huge damages will accrue, and we will be left focusing on the consequences, rather than attempting to avoid the damages in advance,” he said.
Kelemen sees the most potential in technologies that aim to emulate natural processes.
“We should be ready to implement negative emissions at scale if, in 10 years, progress in the energy transition and/or greenhouse gas capture has not been sufficiently fast to avert huge damages due to climate change,” he said. “The rest is guesswork. And politics.”