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.
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.
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.
A London-based reporter for Quartz, Rathi’s Fellowship project focuses on carbon capture technology, an industry that has promised for decades to help stem the world’s carbon-dioxide emissions problem.