Carbon Capture: The Path to Global Salvation or a Divisive Distraction?

The time to prevent catastrophic climate change is running out. Levels of carbon pollution in the atmosphere are at their highest point in over 2 million years, and global fossil fuel emissions haven't even peaked yet.

The urgency of this crisis has led scientists and governments to urgently seek ways to reduce carbon pollution in the air and capture emissions from power plants and industrial facilities.

Long considered controversial, these techniques are increasingly landing a starring role in climate policies.

In Jaffarabad district, Balochistan province, a man and a young person are seen using a satellite dish to help transport children across a flooded area following heavy monsoon rains on August 26, 2022. The heavy rain persisted in parts of Pakistan on August 26, leading the government to declare an emergency in response to monsoon flooding that reportedly impacted over four million people. (Fida Hussain/AFP/Getty Images/File)

Even with significant reductions in emissions, the world would still need to annually remove approximately 10 to 20 billion tons of carbon dioxide, as stated by the IPCC.

There is minimal support for the idea that carbon capture and removal on its own will effectively address climate change.

Howard Herzog, Senior Research Engineer at the MIT Energy Initiative, emphasized that there is no simple solution to the issue. He stated that carbon capture is just one of many options available to address the problem. However, some are concerned that investing in this technology, which is costly, unproven at scale, and far from full development, is a risky gamble in the fight against climate change.

And they criticize these technologies as a dangerous distraction from policies to cut down fossil fuel use.

What is carbon capture?

The term "carbon capture" is frequently used to encompass two categories of technologies: carbon capture and carbon removal. However, it is crucial to note the distinctions between the two.

Carbon capture works to diminish the quantity of carbon emissions that would typically enter the atmosphere by intercepting it at the point of origin, and then either storing it or repurposing it.

Here's how it operates: Rather than releasing carbon pollution (or "flue gas") into the atmosphere by burning fossil fuels, it is captured and subjected to a chemical process.

The typical method for doing this, according to Herzog, is to expose the flue gas to a liquid solvent that extracts the CO2 in a process known as chemical scrubbing. The CO2 is then compressed to remove the water and transported via pipeline or occasionally by ship to a site where it can be repurposed or stored.

According to Herzog, the only viable option for long-term storage of captured carbon is to bury it deep underground, which requires suitable geological conditions. He mentioned that sandstone, a porous rock, is ideal for this purpose, and a layer of denser rock like shale on top can prevent the carbon from seeping through.

In addition, captured carbon can be repurposed to create other products like chemicals, fuel, and cement. However, the environmental impact will hinge on how long the carbon remains trapped. For instance, if captured carbon is used in carbonated drinks, it will simply be released back into the atmosphere.

What is carbon removal?

Enhanced oil recovery is another application of captured carbon that has stirred controversy in the technology's usage. In this process, carbon is injected into wells to extract the remaining hard-to-reach oil, enabling fossil fuel companies to maximize production from aging oil fields.

Carbon removal encompasses a variety of methods designed to eliminate existing carbon pollution from the atmosphere and store it away for good. Trees and oceans serve as natural carbon sinks, actively extracting more carbon from the atmosphere than they release.

Jan Mazurek, senior director of the non-profit ClimateWorks Foundation's carbon dioxide removal program, explained to CNN that increased levels of carbon dioxide in the atmosphere are hindering nature's ability to naturally remove it. Consequently, humans are now actively seeking out ways to accelerate the process of carbon removal.

Some methods involve low-tech solutions, such as mass tree planting. Others aim to enhance natural processes, like fertilizing the oceans with nutrients to promote the growth of carbon-storing marine life, or spreading crushed rock on land to stimulate chemical reactions that capture carbon from the air.

Workers replant mangrove trees at the site of a state-sponsored mangrove reforestation project inEgypt.

Khaled Desouki/AFP/Getty Images

One method, known as bioenergy with carbon capture and storage, includes planting trees or crops to absorb carbon from the air, which is then burned to generate energy. The resulting carbon emissions are captured and stored by injecting them deep underground.

Another technique, direct air capture, is one of the most well-known methods for removing carbon. This process involves using machines to extract air and then remove the carbon using chemicals. The captured carbon can then be injected underground or reused.

What stage is the technology at?

Many of these technologies are at an early stage, remain prohibitively expensive and are a long way from being big enough to have a significant impact.

By 2050, the Paris Climate Agreement's pledge to limit temperature rise to 2 degrees Celsius may require carbon removal technologies to be scaled up by a factor of 1,300, as indicated by a January report with authors from the University of Oxford. Unfortunately, very few countries have established plans to achieve this. Currently, only 0.1% of the roughly 2 billion tons of carbon dioxide removed globally each year comes from technologies like direct air capture, the report revealed.

Climework's Orca project at the Hellisheiði Geothermal Power Plant in Iceland

Temujin Doran/CNN

The world is banking on giant carbon-sucking fans to clean our climate mess. It's a big risk.

The International Energy Agency reports that there are currently 18 small-scale direct air capture plants operating globally, collectively removing approximately 10,000 tons of carbon annually. The largest of these plants is the Orca plant in Iceland, operated by Swiss company Climeworks, with the capacity to remove 4,000 tons of carbon dioxide per year.

The challenge lies in the rapid increase of carbon dioxide in the atmosphere, despite its relatively low composition of only 0.04% of air. This makes the extraction of carbon from the air much more labor and cost-intensive compared to removing it from smokestacks where concentrations are higher. In the realm of carbon capture and storage, there are roughly 35 operational commercial facilities worldwide, as reported by the International Energy Agency, capturing close to 50 million tons of carbon annually.

What are governments doing to scale it up?

Despite the hundreds of these facilities in development, even if they all start operating, the IEA stated on its website that "deployment would remain substantially below what is required in the Net Zero Scenario."

The Biden administration is offering incentives for carbon capture and removal through tax credits as part of the Inflation Reduction Act. In December, the US announced a $3.7 billion investment to jumpstart the carbon capture and removal industry.

"At the time, US Energy Secretary Jennifer M. Granholm stated, 'No matter how fast we decarbonize the nation's economy, we must tackle the legacy pollution already in our atmosphere to avoid the worst effects of climate change.'

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The Calpine Los Medanos Energy Center, a natural gas-fired power plant in Pittsburg, California, US, is shown in this photo taken on Thursday, Feb. 9, 2023. California Governor Gavin Newsom has requested federal energy regulators to look into the recent surge in natural gas prices, which has led to exorbitant utility bills. (Photographer: David Paul Morris/Bloomberg via Getty Images)

The EPA is suggesting new regulations that could significantly reduce greenhouse gas emissions from power plants. The main obstacle for many of these technologies is their economic viability, according to Herzog. For example, a coal plant without carbon capture will always be more cost-effective to operate than one with carbon capture, unless there are policy changes.

Proposed regulations aiming to limit the levels of greenhouse gas emissions from US power plants could have a positive impact. While the new rules would not require carbon capture technology, they would encourage its use. Other countries, such as those in Europe, are taking more aggressive actions, with policies that are growing stronger and compelling industries to take action, according to Herzog.

Why are these technologies controversial?

The EU is aiming to achieve a target of storing a minimum of 55 million tons of CO2 annually by 2030, in addition to its existing emissions trading system that puts a price of around $100 on each ton of carbon pollution.

All methods of carbon removal or capture raise various questions and potential challenges.

Concerns have been raised regarding the large amount of land needed for extensive tree planting or for bioenergy with carbon capture and storage, and the potential conflict with the land needed for agricultural food production.

Direct air capture continues to be costly, and despite assurances from industry leaders that expenses will decrease as the technology advances, there is still substantial progress needed to determine feasibility, according to Herzog. Holly Buck, Assistant Professor of Environment and Sustainability at the University at Buffalo, also noted that this technology necessitates significant amounts of clean energy to operate, further adding to the demand as the world shifts towards electrifying various aspects such as cars and homes.

Biomass fuel storage tanks stand in the Drax power station near Selby, UK. Drax has been developing technology to store emissions from burning biomass.

Simon Dawson/Bloomberg/Getty Images

The transportation and storage of carbon, a crucial aspect of carbon capture and various carbon removal methods, also raise concerns. A carbon pipeline leak in Mississippi in 2020 resulted in over 40 people requiring hospital treatment, highlighting the potential for contamination of drinking water and health risks.

Buck emphasized the importance of constructing the pipeline correctly in the appropriate locations and ensuring thorough monitoring. He also acknowledged the challenge of addressing this issue, noting that it would require effective regulation and monitoring. One consistent critique of these technologies is their tendency to divert attention from efforts to eliminate fossil fuels and potentially enable continued pollution by polluters.

Hundreds of organizations joined forces in 2021 to send an open letter to President Joe Biden and Congress, stating that "technological carbon capture is a harmful diversion." According to Lili Fuhr, Director of the fossil economy program at the Center for International Environmental Law, it is simply the fossil fuel industry's way of avoiding responsibility and prolonging action on climate change.

But others say it cannot be an either-or question.

Some industries, like cement, will be extremely difficult to decarbonize in the short term, according to Herzog. In these cases, carbon capture and removal technologies will be necessary. "This is not a diversion," he explained, "It's a solution where no other solution exists."