Here's the uncomfortable truth behind most long-term plans to combat climate change and keep the world from warming more than 2 degrees Celsius, the commonly accepted limit before the climate effects become catastrophic: Almost none of them say they can do the job just by cutting fossil fuel emissions and investing in renewable energy. Instead, relies on a strategy called carbon capture and storage, or CCS. The problem: CCS only barely exists as a viable technology.
CCS, broadly, is any method that collects CO2 and puts it somewhere it won't contribute to climate change. In theory, with enough CCS systems, it might be possible to reach a world with negative CO2 emissions even if we continue burning fossil fuels. An aggressive CCS campaign could avert most of the damage from climate change without having to convert most of our fossil fuel power plants and vehicles to run on cleaner sources of energy.
In practice, however, CCS is in only the early stages of development, and we're a long way from the dream of being able to burn fossils fuels without worrying about spewing carbon into the air.
Cleaning Up Coal Plants
Today, carbon capture primarily operates as a kind of carbon trap in coal plants. A coal plant is probably the easiest place to collect carbon dioxide since the plant produces so much of it, so it’s no surprise that CCS could find a modicum of success here.
There are a handful of coal plants around the world now using CCS tech. The largest such plant opened in Texas just last year. The plant captures around 5,000 tons of CO2 per day from its exhaust. That’s about 90 percent of all CO2 the plant produces. This CO2 is then piped underground where it stays trapped for millennia. That CO2 will contribute nothing to climate change ever again, and we still get energy from the plant. It sounds like a win-win.
But it isn’t, not really. 5,000 tons of CO2 per day is a lot, but it’s far from being negative emissions. The plant is still emitting CO2 into the atmosphere and contributing to climate change, just at a lower rate. Even if every coal plant in the world used CCS technology this way, climate change would still get worse, not better. That's part of the reason that "clean coal" is a myth.
In addition, that calculus doesn't take into account what happens when the CO2 gets pumped into the ground. In order to make WA Parish's CCS systems profitable, that captured carbon dioxide is then for the purpose of extracting oil faster. This is known as , and works similar to fracking in that it's used to extract oil that's otherwise hard to reach. That oil is then burned in other power plants, or in cars or planes or boats, which just releases more CO2 into the atmosphere.
This is common for the handful of "clean coal" plants currently in operation. CCS is simply too expensive to operate otherwise. CCS proponents hope that these early adopters will accelerate the technology so that someday carbon capture becomes possible to implement as a standalone product.
However, this type of CCS will never give us a negative-emissions future. Even if we could reach zero net emissions from coal plants (which would be great), that’s only one shrinking source of total CO2 emissions. To reach negative emissions, we’ll have to start pulling CO2 from the open air. This is where much of the current research on carbon capture resides.
Out of Thin Air
Many groups are working on technology designed to pull CO2 out of the atmosphere, a herculean task. CO2 concentrations in atmosphere can be than you'd find in the exhaust from coal plants. That's good! But it also means it's harder to make a difference, and that atmospheric CCS costs more money for lower returns.
One startup, , is building large CO2 collectors that can capture up to 50 tons of CO2 per filter per year. The company has already builtusing their tech, the larger of which can remove almost a thousand tons of CO2 per year directly from the atmosphere.
Climeworks, along with other atmospheric CCS startups like and , use compounds like amines or hydroxides to capture CO2. These are usually . When these compounds are heated the chemical reaction is reversed and releases the trapped CO2, which is collected and then sold, pumped underground, or used in specialized applications.
This technology can be successful, but a closer look at the numbers reveals just how far we still have to go. If each Climeworks collector can take 50 tons of CO2 out of the air annually, and the factory can make 150 collectors per year, some quick math shows that if Climeworks keeps building collectors as fast as they possibly can, in ten years they’ll be taking 75,000 tons of CO2 out of the atmosphere annually.
If that sounds like a lot, consider this: humans put last year alone. At the rate Climeworks is making collectors, they’ll need a billion years just to break even. The company’s is to capture 1 percent of yearly emissions by 2025, which is, let’s say, ambitious.
Given these numbers, it’s easy to understand the skepticism of CCS. It’s a pretty new technology that’s nowhere near able to compensate for our carbon emissions, at least not anytime soon. Yet questionable technology might be our only hope. In less than a decade, we’re going to , which means if the world hasn't gone carbon-neutral by that point—and we won’t—then we’re going to need CCS to avoid the worst effects of climate change.
So how do we get to the point where CCS starts making a meaningful difference in CO2 levels? Mostly, by aggressively funding research and implementations of CCS today. Projects like WA Parrish can provide early support for CCS research, and even if they don't sequester a meaningful amount of CO2 themselves, they may discover cheaper and more efficient methods we can use in the future.
In addition, a number of initiatives like the and the are holding competitions for private groups to fund CCS development. "Development means getting projects up and running that we can quickly learn from and iterate and optimize," says Marcius Extavour, the senior director of Energy and Resources at XPrize.
These types of competitions can drive entrepreneurs to find lower-cost, more effective methods of CCS than are currently in use today. Climeworks, Climate Engineering, and Global Thermostat are all part of the , which also has competitors exploring a number of more unconventional solutions. Startups like and are converting CO2 into charcoal, while is capturing CO2 from biofuel plants.
At , competitors are focused on carbon conversion, the process of turning CO2 into a useful product. "We're seeing teams make everything from chemicals and fuels to solid building materials like concrete to advanced materials like graphene nanoparticles or carbon nanotubes," says Extavour.
Together, these competitors are developing dozens of possible ways to make carbon capture profitable. While not all are likely to pan out, at least a few will likely expand into full-fledged industries. The more encouragement we can give to CCS technologies today, the more successful these technologies will be tomorrow.
This isn't exactly the best place to be when fighting climate change. We're still operating under the assumption that CCS will be successful without knowing for sure if it will be. But we have no other choice. Either we figure out how to capture CO2 from the air, or the Earth will be irreversibly ravaged by the effects of climate change. For all our sakes, let's hope it's the former.