Billions are being invested in carbon removal strategies to fight global heating. Will they work?

Questions remain if we can effectively stop cooking the planet by sucking carbon out of the air or using the ocean

Published August 26, 2023 1:59PM (EDT)

Climeworks' DAC plant "Orca", Iceland, in the night (Climeworks)
Climeworks' DAC plant "Orca", Iceland, in the night (Climeworks)

In August, the Biden Administration granted $1.2 billion in federal funding to kickstart a project intended to vacuum carbon dioxide up from the atmosphere to offset global warming

Projects like these, generally known as carbon removal, aim to use industrialized technologies to suck up excess carbon in the atmosphere and bury it in long-term storage underground through CO2 pipelines. The direct air capture project funded by Biden will be located in Texas and Louisiana and is estimated to be the largest such project in the world. 

Similar methods are used in 18 facilities across the globe, and other projects are looking to produce similar results by capturing carbon in the ocean. This relatively new industry is now being backed by serious funding, and time will tell how effective these types of projects will be. Some are doubtful they're ready to take on the vast amount of carbon that needs to be removed at a sustainable price.

Humans emit 35 billion tons of carbon into the atmosphere each year, reducing the earth's ability to cool itself and increasing the rate of global warming. About half of humanity's emissions are absorbed through natural processes in forests and the ocean, but the other half remains in the atmosphere.

In order to meet the regulations of the Paris Climate Agreement, limit global warming to 1.5°C above pre-industrial levels, and prevent the world from reaching "tipping points" in which ecosystems cannot return to equilibrium, two things must be accomplished. Emissions must be reduced, and the excess carbon that is stored in the atmosphere must be removed, said director of the Stanford Woods Institute for the Environment Christopher B. Field, Ph.D.

"No matter how aggressive we are about eliminating future emissions, that CO2 that we've already emitted is still in the atmosphere … even if we drive emissions to zero tomorrow, the warming will not go away," Field told Salon in a phone interview. "If we want to solve the climate crisis, by not only preventing it from getting even warmer than it is now but by returning the temperature to something closer to pre-industrial, we have no choice other than removing some of the carbon dioxide from the atmosphere that's been put there historically."

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How adept at removing carbon these strategies are remains to be seen. In an analysis of 11 projects included in the Department of Energy's 2010 carbon capture plan, seven never got off the ground, one imploded — yes, you read that right — one shut down due to a lack of funding, and the other two "successful" projects barely captured enough carbon to balance out the energy cost of the facilities.

In a TEDTalk last month, former Vice President Al Gore said the amount of carbon captured with these technologies would be a "pathetic little sliver" of emissions compared to what the fossil fuel industry continues to produce. He also criticized the technology for being pricey and energy-demanding.

The Biden Administration set a target of each facility removing millions of tons annually with this technology and costing under $100 per ton of carbon removed. However, the world's largest facility, Orca, in Iceland currently removes just 4,000 tons a year, and most of the 18 facilities in circulation globally cost between $200 to $800 per ton. One analysis found that the energy used for every ton of carbon removed using these technologies was equal to burning roughly 100 gallons of gasoline.

Even less is known about ocean carbon capture than atmospheric capture. However, the ocean is a giant carbon sink that naturally sequesters roughly 30% of emissions, and forests and terrestrial carbon sinks are increasingly depleted through deforestation. As a result, the ocean is becoming increasingly attractive as a place to develop carbon removal technologies, said Matthew Long, Ph.D., a former scientist at the oceanography section of the Climate & Global Dynamics Laboratory at the National Center for Atmospheric Research who now works at the non-profit [C]Worthy.

Mineralized CO2 from Climeworks' DAC plant "Orca", Iceland (Climeworks)

"The problem is, ocean uptake is relatively slow, compared to our rate of emission," Long told Salon in a phone interview. "The idea with ocean carbon dioxide removal technology is to devise ways to accelerate that uptake."

One type of ocean carbon removal, for example, would change the alkalinity of the ocean, increasing the rate of carbon absorption that naturally occurs. But one of the questions that remains to be answered is how a system like this that operates in the wide, open expanse of the ocean can be monitored, said Kate Moran, Ph.D., President & CEO of Ocean Networks Canada. It's also unclear how these projects would impact local communities that depend on the ocean.

"In terms of enhancing ocean alkalinity, the difficult part is really developing the monitoring, reporting and verification, because you're actually influencing a very large body of water," Moran told Salon in a phone interview. "How do you measure that to actually say to some investor, yes, this approach has removed such and such amount of CO2?"

These technologies are still in their infancy, but the goal is to majorly scale them up by 2050, the same date the Biden Administration aims to reach net zero emissions. 

"We're not yet in a world where we have abundant net-zero emissions and electricity, so part of the thing that's happening with these developments now is, we're really in a technology testing phase," Field said. "Things that are the first out of the gate in terms of these new technologies won't necessarily be delivering anything like the magnitude of benefits we'll get eventually."

Many scientists agree that although more data is necessary to understand the full impact of these technologies, both natural and industrial climate solutions will be necessary to offset emissions and reach these goals, said Sarah R. Cooley, Ph.D.the director of climate science at the Ocean Conservancy.

"A lot of researchers are very candid in saying that none of these methods should be considered as a substitute for rapidly decarbonizing and cutting emissions," Cooley told Salon in a phone interview. 

"A lot of researchers are very candid in saying that none of these methods should be considered as a substitute for rapidly decarbonizing and cutting emissions."

She compared emissions to an overflowing kitchen sink. In order to clean up the spill, you'd first shut off the tap before using a paper towel — or, in this metaphor, carbon removal strategies — to clean up the mess.

Still, some fear carbon removal will end up being an excuse for the fossil fuel industry to continue to burn fossil fuels and release emissions. A similar story played out when companies clamored to brand themselves as "carbon neutral," buying carbon credits or planting trees to balance out carbon emissions. In reality, many failed to actually offset them at all, which isn't surprising given that much research doesn't support the idea of carbon offsets being effective.

"The CEO of one of the largest oil companies in the U.S. had told us what [carbon removal] is useful for," Gore said in the TEDTalk. "It's useful to give them an excuse for not ever stopping oil."

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Other scientists say investing in these technologies will be able to get them off the ground and build them up to the kind of carbon removal power necessary to make meaningful change.

"I think we are in a situation that says genuine crisis, and we really need all hands on deck or an all technologies on deck approach," Field said. "That means aggressively decreasing emissions from fossil fuels at the same time we are spinning up other complementary technologies. … We need to figure out some way to do both and we need to do both a lot faster than we're doing."

By Elizabeth Hlavinka

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