Iceland is cold. But it sits atop one of the world’s hottest underground regions, giving the country the ability to tap into a massive store of geothermal energy held by live volcanoes beneath Icelanders’ feet. Drill down only a few hundred meters, and trapped water will come gushing out as high-temperature steam. It’s easy enough to turn that into electricity: just run it through a turbine to drive an electrical generator, like we’ve been doing for over 100 years with any kind of steam.

The only problem is drilling into these volcanic regions also releases carbon dioxide, the major greenhouse gas driving global climate change. Geothermal power is still very clean, producing just 3% of the emissions of a coal plant generating the same power. But Iceland wants to reduce its emissions all the way to zero.

The solution can be found at the Hellisheidi geothermal power plant, Iceland’s largest, just outside the capital Reykjavik. Since 2014, the plant has been extracting heat from underground, capturing the carbon dioxide released in the process, mixing it with water, and injecting it back down beneath the earth, about 700 meters (2,300 ft) deep. The carbon dioxide in the water reacts with the minerals at that depth to form rock, where it stays trapped.

In other words, Hellisheidi is now a zero-emissions plant that turns a greenhouse gas to stone.

This October, it went a step further, partnering with Climeworks, a Switzerland-based startup, to install a machine that sucks carbon dioxide out of the air. That gas is also sent underground, where it, too, eventually turns to rock. The result is a “negative emissions” power plant that literally subtracts carbon dioxide from the atmosphere. As of this writing, the Climeworks machine has already pulled out more than 5 metric tons of carbon dioxide from the air and injected it underground, the equivalent of burying the annual carbon footprint of a household in India.

Critics laughed at those pursuing a moonshot in “direct-air capture” only a decade ago. Now Climeworks is one of three startups—along with Carbon Engineering in Canada and Global Thermostat in the US—to have shown the technology is feasible. The Hellisheidi carbon-sucking machine is the second Climeworks has installed in 2017. If it continues to find the money, the startup hopes its installations will capture as much as 1% of annual global emissions by 2025, sequestering about 400 million metric tons of carbon dioxide per year.

For decades, certain scientists have hoped carbon-capture technologies, deployed at large scales, could save humanity from catastrophic climate change by providing a bridge to a future in which we’ll have enough capacity to create, store, and supply all the world’s energy from only renewable sources. Now that seems imminent. The 2015 Paris climate agreement set a number of goals designed to keep global average temperatures from rising above 2°C as compared to pre-industrial levels—a threshold beyond which there may be irreversible changes to the climate. The foremost authority on the matter, the Intergovernmental Panel on Climate Change, has modeled hundreds of possible futures to find economically optimal paths to achieving these goals, which require the world to bring emissions down to zero by around 2060. In virtually every IPCC model, carbon capture is absolutely essential—no matter what else we do to mitigate climate change.

But carbon-capture technologies have a tortured history. Though first developed nearly 50 years ago, their use in climate-change mitigation only began in earnest in the 1990s and scaling them up hasn’t gone as planned. Over the past decade, billions of dollars have been spent on carbon-capture projects that have not materialized. The most recent failure was the $7.5 billion Kemper Project in Mississippi, whose owners earlier this year announced that instead of finishing the planned low-emissions coal plant, they would just turn it into a natural-gas plant.

Those fiascos have provided ammunition to environmental activists who argue that carbon-capture technologies create a “moral hazard,” making us complacent about the ongoing use of fossil fuels and extending the time we take to wean off them. At the most recent climate talks in Bonn, Germany in November, protesters thronged the only panel the US was officially hosting, because some of the panelists were arguing for the use of carbon capture when burning coal. “Clean coal is a myth!” they shouted.

After a year of reporting, I’ve come to a conclusion: Carbon capture is both vital and viable.

My initial perception of carbon capture, based on what I had read in the press, was to side with the protesters. Carbon-capture technologies seemed outrageously expensive, especially when renewable energy is starting to get cheap enough to compete with fossil fuels. At the same time, my training in chemical engineering and chemistry told me the technologies were scientifically sound. And some of world’s most important bodies on climate change keep insisting that we need carbon capture. Who should I believe?

The question took me down a rabbit hole. After a year of reporting, through visits to large and small carbon-capture plants around the world, and conversations with more than 100 academics, entrepreneurs, policy experts, and government officials, I’ve come to a conclusion: Carbon capture is both vital and viable. Its mass deployment remains a challenge, but not for the reasons that many environmentalists commonly cite. Clearing up those misunderstandings could offer hope in a world full of doom-and-gloom climate stories.

Over the next two weeks, Quartz will publish a series of articles exploring carbon-capture technologies from China to California, showcasing an important but poorly understood part of the world’s race to zero emissions. These are stories of staunch environmentalists who take a different approach to solving the biggest global threat humanity has ever faced, and of a new breed of energy entrepreneur trying to convert carbon dioxide from a liability to an asset.

The case for carbon capture

Let’s first address the elephant in the room.

AP Photo/Martin Meissner

Many would agree that if we have to burn fossil fuels, we should use carbon-capture technologies to negate greenhouse-gas emissions. But why do we need to keep burning fossil fuels?

In many countries, even without subsidies, solar and wind power are starting to compete with fossil fuels on price. The trend points to a world awash in renewable energy not too many years from now. Moreover, there is now little doubt the malice of some fossil-fuel companies delayed efforts to take global action against climate change. Why should we develop technologies that will help them now?

The optimism surrounding renewable energy masks some harsh realities. Despite decades of progress, about 80% of the world’s energy still comes from fossil fuels—the same as in the 1970s. Since then, we’ve kept adding renewable capacity, but it hasn’t outpaced the growth of the world’s population and its demand for energy.

Today, about 30% of total world energy (and 40% of the world’s electricity) is supplied by coal, which emits more carbon dioxide per unit of energy produced than nearly any other fuel source. In a recent analysis (paywall), Deborah Adams of the International Energy Agency, an intergovernmental think tank, notes that the world’s demand for coal actually increased in 2017. (And, not surprisingly, global annual emissions are projected to increase and set a new record.) New coal power plants are being built in most poor countries, “because coal is a relatively cheap, readily available, secure, and reliable source of power,” she writes. “A coal-fired power plant is a massive capital investment and will typically operate for 40 years. This means coal will continue to be a significant part of the energy mix for decades to come.”

The hugely valuable oil and gas industries, accounting for 33% and 24% of total world energy use, respectively, are also entrenched. “Based on what we know now, we would need major technological breakthroughs or weak world growth, including for large emerging and developing economies, for oil demand to peak in the next 20 years,” says Gian Maria Milesi-Ferretti of the International Monetary Fund. Despite the growth in electric vehicles, most oil companies agree that peak oil is “not in sight.”

Even the head of the International Renewable Energy Agency, whose job is to ensure that its more than 180 member countries reach 100% renewable energy, is not exactly gung-ho about the prospects. “In the electricity sector, 100% renewables by 2050 or 2060 may still be achievable,” Adnan Amin told me, “but it’s unlikely to happen for all energy use.” The global electricity sector is responsible for only about 25% of all emissions.

To help get across the challenge we’re facing when it comes to weaning humanity off fossil fuels, we’ve created a simulation where your goal is to reduce the world’s emissions to zero as soon as possible. You can either disincentivize energy sources that produce carbon dioxide or incentivize clean-energy sources, or some combination of both. The projections are based on the open-source En-ROADS tool built by the nonprofit Climate Interactive and MIT Sloan, which simulates the effect subsidies and taxes have on energy use and carbon emissions.

As you may have gathered, there is no way to achieve zero emissions through subsidies and taxes that are within the bounds of what would reasonably ensure that the global economy doesn’t come to a complete halt. (For coal, for example, these would be in the range of ±$80 per metric ton of CO2 emitted). You need something else to reduce emissions. Carbon-capture technologies are essential.

If you’re still not convinced, consider this: there are a handful of industries essential to the modern way of life that generate large amounts of carbon dioxide as a side product of the chemistry of their manufacturing process. These carbon-intensive industries—including cement, steel, and ethanol—produce about 20% of all global emissions. If we want to keep using these products and reach zero emissions, the only option is to have these industries deploy carbon capture.

And we need to reach zero emissions, not just in the energy sector, but completely, across every industry and every part of the world. The last time there was so much carbon dioxide in Earth’s atmosphere was more than 800,000 years ago, when the world’s sea levels were 10 meters (30 ft) higher than today. Even conservative estimates of a 2°C world suggest that by 2100 the oceans could rise more than one meter from today’s levels, which could displace as much as 10% of the world’s population. It would also increase the frequency of heatwaves and intensity of storms, while decreasing crop yields. It’s not something we can wait out.

In theory, there are many ways to get to zero emissions. But time is running out, and it has forced many environmentalists to advocate for the all-of-the-above option, where every technology that can cut emissions, without dragging down the world economy, should be offered a chance to flourish: from energy efficiency and renewable energy to nuclear power and carbon capture.

Reuters/Nick Oxford

Picking the winners we need

Technology development has and continues to improve the lives of billions. Many of these advances haven’t required government support to become reality, but not a single energy technology in recent history has been deployed at large scale without significant help from a benefactor who can take the risk of investing tens of billions of dollars without guaranteed success.

After World War II, the countries with the capacity to build nuclear weapons began to see generating nuclear power as a strategic goal. Governments supported early research, transferred military knowhow on handling radioactive materials to the private sector, and provided generous financial support. The combination created a successful private industry that, today, can build nuclear power plants anywhere in the world.

Another example is the liquefied natural-gas industry. In the 1970s, Japan was becoming dangerously dependent on importing large amounts of coal and oil. Huge fields of natural gas had been discovered in Asia, but at the time, there was little understanding of how to liquefy and safely transport large amounts of the stuff. Japan almost unilaterally absorbed the risks associated with a nascent technology and created the liquefied natural gas industry we know today.

One last example that will resonate with anyone who believes in the value of renewable energy is the story of how Germany came to be responsible for the solar-power revolution we’re living through today. Starting in 2000, the German Renewable Energy Sources Act required that electricity from renewable sources be prioritized over all other sources in the country. The German government also set a fixed price for renewable electricity, and provided low-cost loans for homeowners to install rooftop solar panels. The combination of incentives suddenly created a huge market for solar cells, which were still expensive at the time. At one point, Germany was buying nearly half the world’s supply of solar cells. The huge demand pushed innovation and gradually lowered the price, and today the whole world reaps the benefits of Germany’s efforts.

These examples show it’s possible for national governments, possibly even just one rich country, to fundamentally alter how the world produces energy. All of these developments were strategically important in their time. As we enter the first few years of earnestly trying to reach zero global emissions, the time has come for the strategic development of carbon-capture technologies.

Flickr/Roy Luck under CC BY 2.0 WA Parish power-generating station, with train carriages supplying coal.

There’s a fix

Just outside Houston, Texas, spread over an area of 4,300 acres (more than 3,500 soccer fields), is the WA Parish Generating Station. It comprises four natural gas-fired units and four coal-fired units, producing 3,700 MW of power, enough to meet the energy needs of 3 million US households. The power plant is so big it has its own train station, where, two to three times a day, dozens of carriages unload 15,000 metric tons of coal from the Powder River Basin of Wyoming.

One of the coal units was recently retrofitted with state-of-the-art carbon-capture technology, diverting emissions from the production of about 240 MW of power (enough for 200,000 households). The project, operated by two energy companies, the US’s NRG and Japan’s JX Nippon, was christened “Petra Nova,” which means “new oil” in Latin. When it started operating earlier this year, it became—and remains—the world’s largest coal power plant with carbon-capture technology, with the capacity to capture more than 90% of its emissions, about 1.6 million metric tons of carbon emissions each year. It cost $1 billion to build, $190 million of which came from the US government.

Among a string of failures, Petra Nova stands tall as a carbon-capture project completed on time and within budget. Its success is partly attributable to its use of off-the-shelf technologies that had been tested and proven. The failed Kemper Project, on the other hand, tried to build its own set of technologies to convert coal into gas before doing carbon capture. The main causes for its failure, however, had to do more with reasons beyond technology innovation, such as an unanticipated drop in natural-gas prices.

The idea of capturing and burying emissions is simple, but executing it at scale is complex, NRG spokesperson David Knox warned me before we began the tour. “Petra Nova is really five projects in one,” he said. Petra Nova does all five steps of carbon capture and storage (CCS): generating carbon dioxide, capturing the emissions (which is a two-part process), transporting it to where it will be stored, and injecting it deep underground and then monitoring it.

The generation step is easy. For centuries, we’ve been burning coal to generate heat. In some cases, the heat is used directly and in others it’s converted to electricity.

Part one of the capture step involves taking the mixture of gases in the exhaust spewed out by burning coal, typically about 10% carbon dioxide, 10% oxygen, and 80% nitrogen, and separating out the CO2. Carbon dioxide is slightly acidic, which means it will react with a base. Neither oxygen nor nitrogen is acidic, so in this case, if you add a base into the process, it will selectively trap the carbon dioxide from the mixture.

Once the other gases—which don’t have any greenhouse effects—are vented to the atmosphere, part two of the capture step begins: applying heat breaks the bond between carbon dioxide and the base, creating a pure stream of carbon dioxide, which can be captured before it enters the atmosphere. The base can be reused to capture more carbon dioxide.

Separating out the carbon dioxide is necessary because of the next step: compression and transport. Studies have shown that to ideally store carbon dioxide, the gas should be compressed to 100 times the atmospheric pressure. Compressing a gas that much requires a lot of energy. If the carbon dioxide wasn’t isolated, the full exhaust gas mixture—about nine times more gas—would need to be compressed, consuming nearly as much energy as the entire power plant produces.

After the CO2 is compressed, Petra Nova transports it about 80 miles (130 km) via a pipeline built specially to carry high-pressure carbon dioxide without leaking. Pipes may not seem like a big deal, but many carbon capture projects fail to take off because power plants are too far from injection sites, and there’s no pipeline already set up. It’s not cheap to build your own: industry experts say each mile of a CO2 pipeline can cost as much as $2 million in the Houston area.

Finally, after the carbon dioxide has been transported by pipeline, the gas is injected underground, beneath a depleted oil field. The site wasn’t chosen arbitrarily. Before the CO2 injections began, the oil field was producing about 300 barrels of oil per day, massively down from its peak of 52,000 barrels per day in 1970. Now, the field’s production has risen to about 4,000 barrels per day.

NRG Petra Nova’s carbon-capture unit, in front of the large coal store that powers the WA Parish power plant.

Out of sight

This huge increase in production is thanks to a process called “enhanced oil recovery,” and it’s the largest current market for carbon dioxide. The oil we use to produce energy is typically found in a porous, rocky layer of the Earth’s crust. When an oil field is first discovered, the initial drilling is easy. But after the first easy pickings are sucked out, oil companies need to flood the field with water to push out more of the fossil fuel. Because water and oil don’t mix, however, only a limited amount of the total available oil makes it to the surface even then. Compressed CO2 solves the problem. The gas can get into hard-to-reach crevices of the rocky layer and dissolve the oil there (much like a detergent removes stains from your clothing) flushing out more of it to the surface.

Every time CO2 is pumped into the oil field, about 20% of the gas remains underground. The rest comes back up to the surface with the oil. That CO2-oil mixture is separated by simply lowering the pressure and letting CO2 bubble out of the sticky black liquid. Then the carbon dioxide is recompressed and put back into the field. In the end, all of the greenhouse gas is sequestered.

Enhanced oil recovery currently provides the largest revenue stream for companies capturing carbon dioxide. At a price of about $50 per barrel, Petra Nova is projected to break even—thanks to the extra oil recovered by captured-CO2 injections. If oil prices rise, it may even make a profit from burying carbon dioxide.

This may not sound like a solution to the climate-change problem. After all, investing in this technology could actually help the fossil-fuel industry. But it has the potential to make a huge dent in our CO2 emissions.

Oil companies currently pump about 68 million metric tons of CO2 into oil fields in the US every year. Only 25% of that comes from capturing emissions from human-made sources. The primary source of carbon dioxide for enhanced oil recovery today is—I kid you not—naturally occurring CO2 fields. In other words, oil companies are mining carbon dioxide just as the world is desperately trying to stop producing so much of it.

It’s currently cheaper to mine underground carbon dioxide in one part of the country (where it’s available as a pure gas) and then transport it by pipeline hundreds or thousands of miles away than to go through the whole five-step process necessary to capture it from human-made sources. And oil companies aren’t going to stop doing that until we stop using oil, which is not happening any time soon. If others follow the path Petra Nova has laid out, though, to provide anthropogenic CO2 at a similar or cheaper price, oil companies would give up using geological sources in a heartbeat.

We’ve been injecting carbon dioxide underground since the 1970s, and know plenty about oil and gas fields, so scientists have a good idea of the geology at play. US regulations require that injections of anthropogenic carbon dioxide in oil and gas fields are continually monitored for any possible leakage, and there’s strong evidence that this is a relatively safe feat of engineering.

Eventually—it could be a few years, or decades, depending on how fast the world adopts CCS—we’ll exhaust the storage capacity of depleted oil and gas fields. Luckily, carbon dioxide can be also stored in underground saline aquifers, which are water-permeable rocks saturated with salt water. There, the CO2 mixes in with water and remains trapped underground. (The Sleipner project in Norway, run by Statoil, stored 10 million metric tons of CO2 in saline aquifers between 1996 and 2008.) And CO2 can also be stored in widely available basalt-type rock, where the gas can mineralize into stone (as in Iceland’s Hellisheidi project). Peter Kelemen, a professor of earth and environmental science at Columbia University, warns that we still need more research on saline aquifers and basalt-type rocks before we start shoving all our CO2 emissions in them. But if proven out, research suggests there’s more accessible carbon-storage space than we would need for decades to come.

And yet Petra Nova is one of only 17 large-scale CCS facilities in the world, with just a handful more under construction. The world needs at least 200 facilities by 2025 to stay on track to hit zero emissions. The major reason why we don’t have more is because there isn’t a long-term business model for CCS yet. Studies have shown that revenue from enhanced-oil recovery can provide a bridge to the creation of business models that make CCS more sustainable. Still, not every project will be able to sell its CO2 for use in enhanced-oil recovery.

To environmentally minded entrepreneurs, this demand for more CCS projects presents a major opportunity. Their challenge: either convert carbon dioxide into products people are ready to pay for, or find a way to capture the gas at zero cost.

AP Photo/Susan Montoya Bryan

Catching the S-shaped wave

Issam Dairanieh has always believed technology could help beat climate change. As the head of the oil giant BP’s venture-capital arm in the early 2010s, Dairanieh invested in many clean-energy startups. But he was frustrated with the pace of development. Now, he’s the CEO of the Global CO2 Initiative, where he hopes to accelerate what he started by investing $300 million over the next 10 years in 300 clean-energy startups.

Investing now, Dairanieh believes, will position him well to take advantage of what could become a massive industry. “The potential market for products made from carbon dioxide could be as much as $1.1 trillion by 2030,” says Dairanieh.

“The potential market for products made from carbon dioxide could be as much as $1.1 trillion by 2030”

He’s not the only one placing big bets on carbon-capture tech. Just over the last few years, hundreds of startups have sprung up in search of ways to convert carbon dioxide into new products. As Dairanieh was beginning his work with the Global CO2 Initiative in 2015, the $20-million Carbon X-Prize was wading through the project proposals of 47 teams competing to create the most valuable product from carbon dioxide. Since then, the applicants have been culled to 20 semi-finalists. Each has until February next year to build a prototype that can capture at least 200 kg of carbon dioxide per day for at least three days straight, and convert it into useful products. The teams will use emissions from a coal power plant in Wyoming to test their technology. “We seek inventions that are audacious but possible,” says Marcus Shingles, the CEO of X-Prize.

The X-Prize takes its inspiration from the Orteig Prize, which in 1919 challenged anyone in the world to try to complete the first non-stop flight between Paris and New York. In the end, teams competing spent more than $400,000 trying to win $25,000 (about $6 million and $375,000 in today’s money, respectively). The winner, Charles Lindbergh, changed the commercial aviation industry forever when he made that first non-stop, trans-Atlantic flight in 1927. Barely two years later, more than 170,000 passengers flew across the ocean on commercial airlines.

The rapid development of long-distance flying isn’t as extreme as it sounds. Charles Sandstrom at the Chalmers University of Technology notes that many technologies develop along an S-shaped curve, where progress is slow at first, then reaches a breakthrough and from that point on advances rapidly, until the development reaches the upper limits of scientific possibility. Shingles’ team created the Carbon X-Prize because they believe carbon-dioxide conversion technologies are at that inflection point.

Some companies are already selling CO2 products. Covestro (formerly Bayer Materials) in Germany offers a mattress foam made partially from a polymer with carbon dioxide trapped inside. Tuticorin Chemicals in India is capturing carbon dioxide from burning coal and converting it into soda ash. Another startup I interviewed, which didn’t want to be named because it is in the process of launching a product, is converting carbon dioxide into ethanol to make liquor. (Usually, distilled spirits are made with the ethanol produced by fermenting grains, fruits, or vegetables—a process that actually releases a lot of CO2.)

And there are many more in the development phase. Algoland in Sweden is using emissions captured from a cement plant to feed algae and grow them at faster-than-normal rates, and then selling the protein-rich algae as animal-feed additive. Carbon Engineering in Canada is capturing CO2 from the air and developing a process of converting it into biofuels. Opus 12 in California has a lab prototype producing speciality chemicals from carbon dioxide. Newlight Technologies, also in California, is in the process of commercializing a plastic made in part with CO2. In New Jersey, a startup called Solidia Technologies is working on a form of cement that absorbs carbon dioxide as it sets into concrete. (You can read Quartz’s feature story about Solidia.)

To be sure, the laws of thermodynamics state that converting carbon dioxide into a product will require more energy than was produced when a fossil fuel was burned to generate that same CO2. But that doesn’t make it a bad idea. Renewable energy will keep getting cheaper. Moreover, wind and solar power are intermittent in nature, producing less power on windless or cloudy days. To ensure reliable supply on those days, the overall capacity of renewable power plants needs to be two or three times the amount of power needed for actual use. On the flip side, there will be times when the world is producing more wind and solar energy than we can consume.

“Using abundant renewable cheap energy to do CO2 conversion is no longer crazy,” says Julio Friedmann, a former deputy assistant secretary at the US Department of Energy and an expert in carbon management. “It was crazy three years ago. It’s not crazy now.” (You can read an extended version of Quartz’s conversation with Friedmann.)

Reuters/Javier Barbancho

Seeking breakthroughs

Dairanieh estimates new CO2 products could store as much as 10% of the world’s annual emissions, about 4 billion metric tons of carbon dioxide. However, that still leaves a lot for us to capture and bury, and to do it, we need to figure out how to make the process cheaper.

Ethan Novek won his first science fair at the age of 12; he got his first patent at 16; and now, at 18, he runs his own company, Innovator Energy. Novek took an idea from a school project that won him awards at the International Science and Engineering Fair in 2015, and developed it into a technology he now believes could capture and bury carbon dioxide at $10 or so per metric ton, about 85% less than industry standard. The basic science was validated in a lab at Yale University and published in a peer-reviewed journal; he recently moved to San Antonio, Texas, to build a pilot-scale plant. (You can read Quartz’s feature story about Novek.)

About three hours east of San Antonio, another startup is piloting what could be an even more revolutionary technology. A conventional natural gas plant, though better than coal, is still only 60% efficient. Net Power has built a $150-million facility in Houston, Texas, that utilizes some of the unique properties of CO2 to increase that overall efficiency. Better still, because the plant uses pure oxygen to burn the fuel, the exhaust contains only carbon dioxide and water. That means, after a little bit of cooling and recompression, which require extra energy, that CO2 can be pumped underground. In the end, Net Power gets about the same efficiency as a standard natural-gas power plant but with essentially free carbon capture. The startup’s 50 MW pilot plant—which would produce enough energy to power 40,000 homes—is expected to start burning natural gas in early 2018. If it succeeds, it will be the world’s first fossil-fuel power plant that produces zero emissions at no extra cost. (You can read Quartz’s feature story about Net Power.)

The efforts to make carbon capture cheaper go beyond startups. Researchers are developing membranes, which are essentially plastic sheets containing microscopic holes, to let most gases in an exhaust mix—like oxygen, nitrogen, and argon—pass through, while trapping the much larger CO2 molecule without expending as much energy as needed for conventional methods. Others are working on using a solid base to capture carbon dioxide, unlike the difficult-to-handle liquid bases commonly used today (including at Petra Nova).

AP Photo/Rick Bowmer

Conquering the cost conundrum

Conventional economics suggest we should let technologies compete in a marketplace, and let the best ones win. But, as economist Nicholas Stern puts it, climate change is “the biggest market failure the world has seen.” Most of these nascent carbon-capture technological developments, like other energy technologies, were only born due to government funding. To get them to mature for deployment at scales that would make a difference in our fight against climate change, they’ll need additional government help.

One way to create a realistic CO2 market is through government regulations that specify limits on how much of it can be emitted. It doesn’t have to be all or none—there are ways, that the US has successfully implemented before, to work with the private sector to get it to where it needs to be. Take the case of sulfur emissions.

Sulfur-containing gases emitted by fossil-fuel power plants are a major cause of acid rain and toxic particulate-matter pollution. Following public outcry about air pollution in the 1960s, the US government passed strong regulations to cut sulfur emissions. Crucially, however, the regulations were introduced in a phased manner. First, the government awarded grants to support early-stage research into technology that would scrub sulfur from fossil-fuel emissions. This helped lower the costs of these technologies, making them more palatable for the private sector. Then, the US government slowly tightened limits on how much sulfur-containing gases could be emitted and created a cap-and-trade system that gave companies flexibility on the speed and scope of their implementation. In the end, with the right legislative and regulatory support, the sulphur-scrubbing industry took off.

Nicholas Stern says climate change is “the biggest market failure the world has seen.”

When it comes to greenhouse-gas emissions, one market-friendly government policy is to set a price on carbon production. Economists have already thought this through, developing the concept of a “social cost of carbon” (SCC). A 2014 study looking at different models of SCC concluded that, conservatively, every metric ton of CO2 emitted today will cost the world $125 in future adverse effects. Depending on how much more we continue to emit, SCC goes up or down.

About one-fifth of Norway’s gross domestic product comes from the oil and gas industry. But the country also has a vast coastline and many glaciers, which make it vulnerable to climate change. That’s why Norway was one of the first countries to introduce a carbon tax in 1991.

The impact of carbon pricing was immediate. By 1996, Statoil, the state-run oil and gas multinational, found it cheaper to capture and store the carbon-dioxide emissions from its the Sleipner gas field than to pay the taxes it would have owed if the CO2 was vented into the atmosphere. Sleipner became the first large-scale project in the world to do carbon capture and storage, followed shortly by the Snøhvit gas field, also owned by Statoil. Together, the projects bury more than 1.5 million metric tons of carbon dioxide each year.

Broadly speaking, the carbon tax has added rocket fuel to Norway’s transition towards a zero-emissions country. In 2016, the country’s parliament announced it was moving its emissions goals up 20 years; it will now attempt to achieve net-zero emissions by 2030, instead of 2050. And that was with a tax of just about $70 per metric ton of carbon dioxide, far lower than a SCC of $125.

Today, carbon taxes exist in some form in more than 15 countries around the world. The UK introduced a carbon-floor price in 2011. Now, six years later, the country that led the coal-powered industrial revolution is on the verge of eliminating the use of the dirty fuel. But perhaps the most instructive example of how carbon taxes affect emissions comes from Australia. When the country announced it would levy the tax in 2012, its CO2 emissions fell in anticipation of the new policy going into effect. For nearly two years, emissions continued to dive until a political shakeup led to a new government that reversed the policy in late 2014. Immediately, CO2 emissions began to rise again; by 2016, they had returned to 2012 levels.

Bring in parity

The Paris climate agreement’s goal to reach zero emissions have reinvigorated interest in carbon-capture technologies across the world. Canada has the most CCS projects besides the US, with three in operation and two to launch in 2018. Norway has some of the longest-running after the US, and is planning to build more in the near future. Australia will soon be home to one of the world’s largest CCS plants: the Gorgon project, expected to launch in 2018, will separate carbon dioxide from natural gas, and bury nearly 4 million metric tons of CO2 annually. India is planning to finance at least one carbon-capture project before 2020. Finally, though China currently has no completed large-scale CCS projects, it has more of them in the planning phase than any other country. (You can read Quartz’s feature story on China’s efforts.)

However, the world continues to look to the US’s advances in carbon capture. There’s one thing the many innovations mentioned in this article have in common: the US Department of Energy (DOE). The department gave grants to Petra Nova to build the first coal-power plant with CCS, to Solidia Technologies to help with research, to Newlight Technologies to help scale up their technology, and to Opus 12 in the form of lab facilities. Ethan Novek is currently applying for a DOE grant. So it matters what US leadership thinks about climate change.

“Leadership matters tremendously,” a former US government official told me. “Because it decides the priorities for the country.” Under secretary Steven Chu, the DOE focused on solar power, energy efficiency, and biofuels. When Ernest Moniz took over the job, the department shifted towards nuclear power, electrical-grid resiliency, and CCS.

It’s not clear what current DOE secretary Rick Perry wants. On the one hand, he was happy to be at the ribbon-cutting ceremony for Petra Nova. On the other, he has raised doubts about whether human-caused carbon emissions are the major cause of climate change. (They are. Perry’s position has no scientific basis.) Perry’s boss, Donald Trump, behaves even more unpredictably. On the one hand, Trump promotes “clean coal” (even if he doesn’t understand what it means). On the other, he wants to cut the budget of the Office of Fossil Energy in the DOE, which is responsible for funding carbon-capture technologies.

Between 2010 and 2016, the world spent $2.3 trillion on renewable energy and only $10 billion on CCS.

The US is still the global leader in carbon-capture technologies. An early start at enhanced-oil recovery in the country created industry expertise in the technologies and led to the creation of the world’s largest network of CO2 pipelines (more than 4,000 miles, or 6,400 km, long). Those infrastructure and technology investments have helped the US oil and gas industry remain among the world’s most valuable.

But the US and the rest of the world need to do a lot more, and quickly. Between 2010 and 2016, the world spent $2.3 trillion on renewable energy, largely thanks to government subsidies for the renewable sector (like Germany’s push for solar cells). In the same period, CCS got only $10 billion in investment, according to the International Energy Agency. No surprise then, that the Global CCS Institute, a not-for-profit group funded by governments and corporations, calls for climate-change policy parity: If we want to save the world, the organization argues, we should provide the same incentives to any technology that cuts carbon emissions.

AP Photo/Gregory Bull

Vote your mind

The term “clean coal” is a huge problem. It masks the fact that coal is a dirty source of energy. Current so-called “clean-coal” technologies nearly eliminate sulfur and mercury emissions, but they don’t reduce carbon emissions. And the use of coal is seriously hurting our fight against climate change. At the same time, over the past 20 years, coal has brought electricity for the first time to some 1.6 billion people. And if we care about the development of all people, our energies would be better spent cutting emissions rather than being religious about one fuel or another.

The trouble is that environmentalists conflate “clean coal” with CCS. If the world is to hit zero emissions, we will need to apply CCS not just to coal power plants but also to natural-gas power plants and then to every carbon-emitting industry. In other words, CCS really isn’t about coal. We cannot afford that confusion any more because time is running out. Ultimately, whether or not CCS is deployed will come down to people, who through their elected governments, can push for the right policies to be adopted.

“There’s a perception around CCS that it adds a burden, as opposed to it accomplishes a goal. That needs to change.”

That’s why perceptions matter. Consider what’s happening to nuclear power around the world. Following the 2011 Fukushima meltdown, a poll of 23,000 people across 23 countries showed a sharp decline in people’s appetite for nuclear power—a near-zero-emissions source of energy. In the disaster, no one was killed or sickened by radiation. The Japanese government’s response was to assume the worst, and the panic that ensued spread a fear of radiation across the world. Germany, formerly a champion of nuclear energy, has had to turn on coal-power plants after implementing policies to limit the use of nuclear power. The upshot is the country’s emissions have increased in recent years, instead of fallen as they have in most of the rich world. The notion of “clean coal” has similarly shaped wrong perceptions of CCS.

In addition, even many of those who do understand that CCS is distinct from “clean coal” don’t support it because of a natural human bias towards production rather than reduction. “CCS doesn’t make anything new. You just don’t have emissions,” says Julio Friedmann, the former DOE official. “There’s a perception around CCS that it adds a burden, as opposed to it accomplishes a goal. That needs to change.”

The case for how people should think about CCS was best made by Peter Kelemen, who told a story at the Columbia Global Energy Summit held in April this year. In about 1820, London became the world’s largest and arguably most important city. It wasn’t just the capital of Great Britain; it was the seat from which the empire’s rulers controlled nearly half the world’s population. But London, in some ways, was still a backwater—it lacked a central sewer system. “If you were poor, you threw it down the street,” Kelemen told the audience. “If you were wealthy, you had a pipe that took it to a cesspool.”

John Snow, now known as the father of epidemiology, undertook research that showed links between these cesspools and at least three cholera outbreaks, which killed more than 30,000 people in first half of the 19th century. To add to the woes, most of the human waste eventually found its way into the Thames River. “I can certify that the offensive smells, even in that short whiff, have been of a most head-and-stomach-distending nature,” Charles Dickens wrote in a letter to a friend in 1857.

Punch/Wellcome Library Scientist Michael Faraday dropped pieces of white paper into the river to “test the degree of opacity.”

“Then in 1858, there was a summer when it didn’t rain,” Kelemen continued. The Thames dried up, and the stench got stronger. It was called the Great Stink. The Queen and the royal court left London; members of parliament debated moving to Oxford. Fortunately, instead of leaving, they passed legislation to do something. “They dug up all the largest roads in the world’s largest city, and they installed central sewers over the next 10 years,” Kelemen said. “It cost about 2% of GDP, and even today it costs about 1% of GDP to maintain the sewers. No one questioned whether that was worth it. Until people think throwing CO2 in the air is like throwing poop in the street, we’re not going to spend what it costs. At 2% of global GDP, we can make the CO2 problem go away.”

“Until people think throwing CO2 in the air is like throwing poop in the street, we’re not going to spend what it costs.”

Framed this way, the long-term economics of CCS seem not only feasible, but eminently reasonable. The International Energy Agency estimates that the world needs to be burying at least 6 billion metric tons of CO2 per year by 2050. Though Petra Nova won’t say it, experts estimate the project’s carbon-capture cost to be about $60 per metric ton of CO2. That’s half the social cost of not capturing the same carbon. Knox, Petra Nova’s spokesperson, says that were the company to build a second unit, costs would be at least 20% lower than the first project, thanks to the lessons learned.

Even using a conservative number, like $60 per metric ton, all the world would need to pay to start to make the CO2 problem go away today is $360 billion. For comparison, the world’s GDP is forecast to be $78 trillion in 2017.

In other words, we could save the planet from disastrous climate change for less than 0.5% of world GDP in today’s economy—much lower than Kelemen’s already modest estimate.

Last resort

If people don’t change their mind about CCS and governments don’t invest to make deployment of CCS at large scale a reality, the world will soon exceed the carbon budget required to keep global temperature rise below 2°C. Some models suggest we’re already on track to cross that point, and the world will have to turn to some form of the “direct-air capture” technology currently being tested at a humble scale in Iceland. To suck up carbon dioxide from the air at the levels to stop global-temperature rise, we’d need to deploy hundreds of millions of the machine now working at the Hellisheidi plant.

That’s a scary prospect. CCS might seem expensive now, but direct-air capture in the second half of the 21st century will cost many multiples more. The reason is simple physics: CCS happens at the source of emissions, which typically contain more than 5% carbon dioxide in the exhaust gas mix. The concentration of CO2 in the air is just 0.04%—100 times more dilute. Far more energy would be required to pull carbon dioxide straight out of the air, and that means far more money. The most recent estimates suggest the cost of direct-air capture could be as high as $600 per metric ton—nearly 10 times the cost of carbon-capture technologies today.

That economic hit would hurt a lot more than deploying carbon capture at large scale today. But even that may not hurt as badly as uncontrolled climate change. The latest projections show that, as soon as 2027, the cost of rising temperatures will be $360 billion per year for the US alone. The damage to the rest of world could be four times as much.

Prevention is better than cure. And, for our dying planet, either is better than doing nothing.

The article was edited by Elijah Wolfson and graphics were produced by David Yanofsky.