Carbon capture and storage (CCS) is a method used to remove carbon dioxide (CO₂) from sources like factories or power plants before it enters the air. The CO₂ is then moved to a safe place underground for long-term storage. Most of the CO₂ captured each year is used in enhanced oil recovery (EOR), a process where CO₂ is injected into old oil wells to help extract more oil. This CO₂ is usually left underground after use. Because EOR uses CO₂, CCS is also called carbon capture, utilization, and storage (CCUS).

Oil and gas companies started using CCS-related methods in the mid-20th century. These early methods were mainly used to clean natural gas and increase oil production. Beginning in the 1980s and especially in the 2000s, CCS was discussed as a way to reduce greenhouse gas emissions. A 2022 review found that about 70% of planned CCS projects had not started, and over 98% of electricity-related CCS projects failed. As of 2024, CCS was operating at 44 plants worldwide, capturing about one-thousandth of global CO₂ emissions. Around 90% of these operations involved the oil and gas industry. CCS plants often need more energy to run, which means they may use more fossil fuels and create more pollution during fuel extraction and transport.

CCS may play a limited but important role in reducing greenhouse gas emissions. However, other methods, such as solar and wind energy, using electricity instead of fossil fuels, and improving public transportation, are cheaper and more effective at reducing air pollution. Because of its high cost and limitations, CCS is expected to be most useful in specific areas, such as heavy industries and retrofitting old power plants. In situations where natural gas use is reduced significantly, CCS can help lower emissions from gas processing. In electricity generation and hydrogen production, CCS is expected to support the move toward renewable energy. CCS is also part of a system called bioenergy with carbon capture and storage, which can remove carbon from the atmosphere under certain conditions.

The success of CCS in reducing emissions depends on how well it captures CO₂, how much extra energy it uses, how much CO₂ leaks from storage sites, and problems that prevent plants from working as planned. Some large CCS projects have stored much less CO₂ than expected. There is debate about whether using captured CO₂ to extract more oil helps the environment. Many environmental groups view CCS as an untested, costly technology that keeps people relying on fossil fuels. They argue that other emission-reduction methods are more effective and that CCS distracts from these solutions.

Some international climate agreements mention the idea of fossil fuel abatement, which is not clearly defined but generally refers to using CCS. Almost all CCS projects today have received financial help from governments. Countries that support or require CCS include the United States, Canada, Denmark, China, and the United Kingdom.

Terminology

The Intergovernmental Panel on Climate Change (IPCC) explains that carbon capture and storage (CCS) and carbon capture, utilization, and storage (CCUS) are similar terms often used in the same way. These terms mostly describe enhanced oil recovery (EOR), a process where captured carbon dioxide (CO₂) is injected into oil reservoirs that are nearly empty to help extract more oil. EOR is both "utilization" and "storage" because the CO₂ remains underground permanently. Before 2013, this process was called CCS. In 2013, the term CCUS was introduced to emphasize its economic benefits, and it became more commonly used.

About 1% of captured CO₂ is used to make products like fertilizer, fuels, and plastics. These uses are examples of carbon capture and utilization. In some cases, these products store carbon permanently, which also qualifies as CCS. However, for a process to be called CCS, the carbon must be stored long-term. Therefore, using CO₂ to make fertilizer, fuel, or chemicals is not considered CCS because these products release CO₂ when they are burned or used.

Some sources use the terms CCS, CCU, or CCUS to include methods like direct air capture or tree-planting, which remove CO₂ from the air. In this article, the term CCS follows the IPCC’s definition, which requires CO₂ to be captured from specific places, such as a natural gas processing plant.

History and current status

In the natural gas industry, technology to remove carbon dioxide (CO₂) from natural gas before it is sold was patented in 1930. This process is necessary to prepare natural gas for sale and use. After CO₂ is removed, it is often released into the air. In 1972, American oil companies found that CO₂ could be used profitably for enhanced oil recovery (EOR). Later, natural gas companies in Texas started capturing CO₂ from their processing plants and selling it to local oil producers for EOR.

The use of carbon capture and storage (CCS) to reduce human-caused CO₂ emissions began later. In 1977, an Italian scientist named Cesare Marchetti suggested that CCS could help reduce emissions from coal power plants and fuel refineries. Small projects to test CCS were first shown in the early 1980s, and a cost analysis was published in 1991. The first large-scale project to capture and store CO₂ with monitoring was started at the Sleipner gas field in Norway in 1996.

In 2005, the Intergovernmental Panel on Climate Change (IPCC) released a report that emphasized CCS, leading to increased government support for CCS in many countries. Governments spent about US$30 billion on subsidies for CCS and for producing hydrogen from fossil fuels. By 2020, 149 projects were planned to store 130 million tonnes of CO₂ each year. However, about 70% of these projects were not completed. Reasons included limited funding, lack of long-term plans for stored CO₂, high costs, limited public support, and budget challenges.

In 2020, the International Energy Agency (IEA) noted that CCS has had limited success despite its potential to reduce climate change effects. By July 2024, 44 commercial-scale CCS plants were operating globally. Sixteen of these plants removed naturally occurring CO₂ from raw natural gas. Seven were used for hydrogen, ammonia, or fertilizer production; seven for chemical production; five for electricity and heat; and two for oil refining. CCS was also used in one iron and steel plant. Three facilities focused on transporting and storing CO₂. As of 2024, the oil and gas industry operated 90% of global CCS capacity. Together, these facilities captured about one-thousandth of the world’s greenhouse gas emissions.

Eighteen CCS facilities were in the United States, fourteen in China, five in Canada, and two in Norway. Australia, Brazil, Qatar, Saudi Arabia, and the United Arab Emirates each had one project. By 2020, North America had over 8,000 kilometers (5,000 miles) of CO₂ pipelines, with two pipeline systems in Europe and two in the Middle East.

Process overview

CCS facilities capture carbon dioxide before it enters the atmosphere. Usually, a chemical solvent or a material with tiny holes is used to separate the CO₂ from other gases in a plant's exhaust. Most often, the gas stream moves through an amine solvent, which holds onto the CO₂ molecules. This CO₂-rich solvent is then heated in a special unit to release the CO₂. The CO₂ is cleaned to remove unwanted substances and cooled to the right temperature for compression. The purified CO₂ is compressed and sent for storage or use, and the solvent is reused to capture more CO₂ from the facility.

After CO₂ is captured, it is often compressed into a special form called a supercritical fluid and injected underground. Pipelines are the least expensive way to move large amounts of CO₂ on land or, depending on the distance and amount, across the ocean. Transporting CO₂ by ship has been studied. CO₂ can also be moved by truck or train, but these methods cost more per ton of CO₂.

Technical components

CCS processes use several tools and systems working together. These systems separate and clean CO₂ from a gas mixture, compress and move the CO₂, inject it underground, and check the whole process.

There are three main ways to separate CO₂ from a gas mixture: post-combustion capture, pre-combustion capture, and oxy-combustion:

• In post-combustion capture, CO₂ is removed after burning fossil fuel.
• For pre-combustion capture, the fossil fuel is partly burned in a special machine called a gasifier. This creates a mix of gases (CO and H₂). The CO in this mix reacts with steam (H₂O) and changes into CO₂ and H₂. The CO₂ can then be collected from a nearly pure stream. The H₂ can be used as fuel. This method has both benefits and challenges compared to post-combustion capture.
• In oxy-fuel combustion, fuel is burned using pure oxygen instead of air. The gas released is mostly CO₂ and water vapor. When the water vapor is cooled and turned into liquid, the remaining gas is almost pure CO₂. A problem with this method is that it needs a large amount of oxygen, which is costly and uses a lot of energy.

Absorption, or using amines to clean CO₂, is the most common method. Other methods being studied include using special membranes to separate gases, chemical looping combustion, calcium looping, and materials like metal-organic frameworks or solid sorbents.

Impurities in CO₂, such as sulfur dioxide and water vapor, can change how CO₂ behaves as a liquid or gas. These impurities may also cause damage to metal pipes and wells. If CO₂ has these impurities, a process is needed to remove them.

Storage and enhanced oil recovery

Storing carbon dioxide (CO₂) involves injecting captured CO₂ into deep underground rock layers that have many tiny spaces (pores) and are covered by a layer of rock that does not allow liquids or gases to pass through. This covering rock keeps the CO₂ trapped underground and stops it from rising to the surface. Before injection, CO₂ is often compressed into a special liquid form called a supercritical fluid. When this compressed CO₂ is injected into the rock layers, it moves through the pores and fills the spaces. These rock layers must be more than 800 meters (about 2,600 feet) deep to keep the CO₂ in a liquid state.

As of 2024, about 80% of the CO₂ captured each year is used for enhanced oil recovery (EOR). In EOR, CO₂ is injected into oil fields that have already lost much of their oil. The CO₂ mixes with the oil, making it lighter so it rises faster to the surface. This process also increases the pressure in the rock, helping the oil move more easily toward the wells where it is collected. For every tonne of CO₂ injected, this method can produce about two extra barrels of oil. However, using this oil releases about one tonne of CO₂. Some of the CO₂ mixed with the oil can be captured again and injected underground multiple times, reducing losses to about 1%. This recycling process requires a lot of energy.

About 20% of captured CO₂ is injected into deep underground areas filled with salty water, called saline aquifers. These areas are made of rocks that are both porous and allow liquids to flow through them. Globally, saline aquifers have more storage potential than oil fields. Storing CO₂ in saline aquifers is usually less expensive than EOR because it does not require very pure CO₂ and because suitable locations are more common, which can reduce the length of pipelines needed.

Other storage methods are being tested or studied as of 2021. CO₂ can be injected into coal beds to help release more methane gas, a process called enhanced coal bed methane recovery. Another method, called ex-situ mineral carbonation, involves mixing CO₂ with materials like mine waste or industrial waste to create stable minerals, such as calcium carbonate. In-situ mineral carbonation involves injecting CO₂ and water into underground rock layers made of reactive minerals like basalt. In these layers, CO₂ can quickly react with the rock to form stable carbonate minerals. Once this reaction is complete, the risk of CO₂ escaping is nearly zero.

The world has a very large potential for storing CO₂ underground, and this is unlikely to limit the use of carbon capture and storage (CCS) technology. Scientists estimate that the total storage capacity is between 8,000 and 55,000 gigatonnes. However, only a smaller portion of this may be practical to use due to technical or cost challenges. Estimates for storage capacity are uncertain, especially for saline aquifers, where more research is needed.

In underground storage, CO₂ is kept in place through several methods: structural trapping by a layer of rock that does not allow CO₂ to pass through (called a caprock), solubility trapping when CO₂ dissolves in water in the rock pores, residual trapping when CO₂ remains trapped in small spaces within the rock, and mineral trapping when CO₂ reacts with the rock to form stable minerals. Mineral trapping takes a long time to complete.

After injection, supercritical CO₂ tends to rise until it is blocked by a caprock. Once blocked, it spreads sideways until it finds a gap. If there are cracks or fault lines near the injection site, CO₂ could move along these cracks and escape to the surface, which could be dangerous. If the pressure from injecting CO₂ becomes too high, the rock layers might break, possibly causing small earthquakes. While these earthquakes are likely too small to damage buildings, they could still cause CO₂ to leak.

According to the Intergovernmental Panel on Climate Change (IPCC), well-managed storage sites are likely to keep over 99% of injected CO₂ underground for more than 1,000 years. This means there is a 66–90% chance of this happening. Long-term leakage estimates depend on computer models because there is limited real-world data. Even a small amount of CO₂ leakage over a long time could have a major impact on the climate.

Social and environmental impacts

Facilities that use carbon capture and storage (CCS) require more energy than those that do not. The extra energy needed for CCS is called an "energy penalty." The size of this penalty depends on the source of CO₂. If the gas from the source has a very high amount of CO₂, extra energy is only needed to remove water, compress, and move the CO₂. If the facility produces gas with less CO₂, like power plants, energy is also needed to separate CO₂ from other gases in the gas mixture.

Early studies showed that to make the same amount of electricity, a coal power plant using CCS would need to burn 14–40% more coal, and a natural gas power plant would need to burn 11–22% more gas. In coal power plants with CCS, about 60% of the energy penalty comes from capturing CO₂, 30% from compressing the CO₂, and 10% from pumps and fans.

Depending on the technology used, CCS can use large amounts of water. For example, coal-fired power plants with CCS may need to use 50% more water than those without CCS.

Because CCS facilities need more fuel to make the same amount of electricity or heat, using CCS increases problems caused by fossil fuels before they are burned. These problems include pollution from mining coal, emissions from transporting coal and gas, emissions from burning gas, and leaks of methane gas.

Since CCS facilities need more fossil fuel to be burned, CCS can increase air pollution from those facilities. This pollution can be reduced with equipment, but no equipment can stop all pollution. Many CCS systems use liquid amine solutions to capture CO₂, and these chemicals can also be released into the air if not properly controlled. Some of these chemicals, like volatile nitrosamines and nitramines, can cause cancer if inhaled or swallowed.

Studies that look at both the effects before and after CO₂ is captured show that adding CCS to power plants increases harm to human health. The effects of adding CCS in industries are less clear. These effects depend on the type of fuel used and the technology for capturing CO₂.

After CO₂ is injected into underground rock layers, there is a risk that nearby shallow groundwater could become polluted. This could happen if CO₂ moves into groundwater or if saltwater pushed aside by CO₂ moves into groundwater. Choosing good locations for storage and monitoring over time are needed to reduce this risk.

CO₂ is a colorless and odorless gas that stays close to the ground because it is heavier than air. In humans, breathing air with more than 5% CO₂ (50,000 parts per million) can cause breathing problems and acid buildup in the blood. Air with more than 10% CO₂ can cause seizures, unconsciousness, or death. Air with more than 30% CO₂ can cause loss of consciousness in seconds.

Pipelines and storage sites can cause large accidental releases of CO₂ that can harm nearby communities. A 2005 report said that CO₂ pipelines, mostly in areas with few people, have very few accidents compared to pipelines for oil and gas. The report also said that storing CO₂ underground is as safe as storing natural gas underground if proper planning, rules, monitoring, and plans for fixing problems are in place. As of 2020, how CO₂ pipelines can fail is less understood than for oil or gas pipelines, and few safety rules are specific to CO₂ pipelines.

Although rare, accidents can be serious. In 2020, a CO₂ pipeline broke after a mudslide near Satartia, Mississippi, causing people nearby to lose consciousness. About 200 people were evacuated, and 45 were hospitalized. Some had long-term health effects. High CO₂ levels also stopped vehicle engines, making rescue efforts harder.

Adding CCS to existing facilities can help keep jobs and economic stability in areas that rely on industries that produce a lot of emissions, while avoiding the problems that come from closing these facilities early.

In the United States, many facilities that could use CCS are in communities that already face environmental and health problems from living near power or industrial plants. These facilities are more often in poor or minority communities. While CCS can help reduce pollution other than CO₂, some groups are worried that CCS might be used to keep these facilities operating longer and continue local harm. Many local groups would prefer to shut down these facilities and invest in cleaner methods, like using renewable energy.

Building pipelines often involves setting up temporary work camps in remote areas. In Canada and the United States, pipeline construction in remote communities has been linked to social problems, such as sexual violence. This history has led some Indigenous communities to oppose building CO₂ pipelines.

Cost

CCS projects often stop because of high costs, low technology development, and few ways to make money. Large projects usually need a lot of money at the start, sometimes up to several billion dollars.

The cost of CCS depends on where the CO₂ comes from. If a facility produces gas with a lot of CO₂, like in natural gas processing, capturing and compressing it costs about USD 15–25 per tonne. However, power plants, cement plants, and iron and steel plants produce gas with less CO₂, making capture and compression more expensive, costing USD 40–120 per tonne CO₂. In the United States, moving CO₂ through onshore pipelines costs between USD 2–14 per tonne CO₂. More than half of onshore storage space is estimated to be available for less than USD 10 per tonne CO₂.

CCS projects use many technologies that are specially designed for each location. This customization makes it harder for the industry to lower costs by gaining experience through repeated use.

Role in climate change mitigation

Compared to other ways to reduce emissions, carbon capture and storage (CCS) is very expensive. For example, removing CO₂ from fossil fuel power plants can increase costs by US$50–$200 per tonne of CO₂ removed. Many other methods to reduce emissions cost less than US$20 per tonne of CO₂ avoided. Options that can reduce emissions more affordably than CCS include public transportation, electric vehicles, and energy efficiency improvements. Wind and solar power are often the cheapest ways to produce electricity, even when compared to power plants that do not use CCS. The cost of renewable energy and batteries has dropped so much that it is hard for fossil fuel plants with CCS to compete. However, wind and solar power are not always reliable because they depend on weather and location, so completely stopping fossil fuel power plants may not always be possible.

In studies about reducing climate change, CCS is described as having a small but important role in cutting greenhouse gas emissions. A 2014 report by the IPCC said that not using CCS at all would make it 138% more expensive to keep global warming below 2 degrees Celsius. Relying too much on CCS is also costly and may not be technically possible. The International Energy Agency (IEA) said that trying to stop oil and gas use only through CCS and direct air capture would cost USD 3.5 trillion each year, which is about the same as the total yearly income of the entire oil and gas industry. CCS is especially important in certain areas where reducing emissions without it is difficult or expensive:

• Heavy Industry: CCS is one of the few ways to cut emissions from making cement, chemicals, and steel. Some emissions come from chemical processes, and others come from burning fuels. For example, about one-third of emissions from cement production come from burning fuels, and two-thirds come from chemical reactions. The Global Cement and Concrete Association says CCS could reduce emissions by 36%. Cleaner industrial methods are being developed, but they are not yet widely used.
• Retrofits: CCS can be added to existing coal and natural gas power plants and factories to reduce their emissions while keeping them running.
• Natural Gas Processing: CCS is the only way to reduce emissions from natural gas processing. This does not stop emissions from burning the gas.
• Hydrogen Production: Most hydrogen today is made from natural gas or coal. CCS can be used to capture emissions from these processes.
• Complement to Renewable Energy: In a 2050 plan for zero emissions, the IEA says 251 gigawatts of electricity could come from coal and gas plants with CCS, while 54,679 gigawatts could come from solar and wind. Solar and wind are usually cheaper, but power plants that burn fuel can produce electricity anytime, which helps meet energy needs during high demand. Some experts say using 100% renewable energy is possible in many regions, which might make CCS unnecessary in the electricity sector. However, this could cost more. A new idea called CO₂-Plume Geothermal combines carbon storage with geothermal energy.
• Bioenergy with CCS (BECCS): This process uses biomass to create energy and captures the CO₂ produced. Under certain conditions, BECCS can remove CO₂ from the atmosphere.

The IPCC said in 2022 that using CCS faces many challenges, including technical, economic, and social issues. CCS can only be used at large, stationary sources, so it cannot reduce emissions from vehicles or homes. The IEA warns that expecting too much from CCS and direct air capture is a mistake. To meet the goals of the Paris Agreement, CCS must be used alongside a sharp drop in fossil fuel use.

When CCS is used for electricity, most studies say 85–90% of CO₂ is captured. However, industry leaders say actual capture rates are about 75%, and they want governments to accept this lower rate. The success of CCS projects depends on more than just capture rates. Other factors include the energy needed to power CCS, where that energy comes from, and CO₂ leakage after capture. The energy for CCS often comes from fossil fuels, which produce emissions. Some studies say CCS may not reduce emissions much, or could even increase them. For example, a study found that a CCS project at a coal plant only reduced emissions by 10.8% over 20 years.

Some CCS projects have not stored as much CO₂ as planned. For example, at the Shute Creek Gas Processing Facility, about half of the captured CO₂ was sold for oil recovery, and the other half was released into the air because it was not profitable. At the Gorgon gas project in Australia, issues with underground water stopped two-thirds of captured CO₂ from being stored. A 2022 study of 13 major CCS projects found that most stored far less CO₂ than expected or failed completely.

There is debate about whether using CCS with enhanced oil recovery (EOR) helps the climate. EOR is energy-intensive because CO₂ must be separated and injected multiple times. If CO₂ losses are kept low (1%), EOR uses about 0.23 tonnes of energy for every tonne of CO₂ stored. When oil extracted through EOR is burned, CO₂ is released. If these emissions are counted, CCS with EOR often increases overall emissions compared to not using CCS. If these emissions are not counted, CCS with EOR reduces emissions. Some argue that EOR oil replaces oil from other sources, but a 2020 study found scientists were split on this issue.

The IEA’s model says 80% of oil from EOR replaces other oil on the market. Using this model, it estimated that burning EOR oil produces 0.13 tonnes of CO₂ per tonne of CO₂ stored, plus 0.24 tonnes from EOR itself.

As of 2023, CCS captures about 0.1% of global emissions, or 45 million tonnes of CO₂. Climate models from the IPCC and IEA predict CCS will capture about 1 billion tonnes of CO₂ by 2030 and several billion tonnes by 2050.

Political debate

Carbon capture and storage (CCS) has been a topic of discussion among political leaders since the early 1990s, when the United Nations Framework Convention on Climate Change (UNFCCC) negotiations began. This issue continues to cause disagreement among people and groups.

Fossil fuel companies have strongly supported CCS, describing it as a way to innovate and save money. These companies and energy providers that rely on fossil fuels often say that using fossil fuels will increase in the future and claim that CCS can help continue using fossil fuels. Their statements usually focus on CCS as a solution to climate change but rarely mention reducing the use of fossil fuels. According to the International Energy Agency, in 2023, investments in the oil and gas industry were more than double what is needed to produce fuel that would help limit global warming to 1.5°C.

Representatives from the fossil fuel industry have been active at United Nations climate conferences. At these meetings, they have pushed for agreements that emphasize reducing emissions from fossil fuels using CCS, rather than reducing the use of fossil fuels themselves. At the 2023 United Nations Climate Change Conference, at least 475 people who work for CCS-related groups were allowed to attend.

Many environmental organizations, such as Friends of the Earth, strongly oppose CCS. In surveys, these groups rate CCS-related fossil energy as low as they rate nuclear energy. Critics argue that CCS is an untested, costly technology that keeps the world dependent on fossil fuels. They believe other methods of reducing emissions are more effective and that CCS distracts from these efforts. They prefer government funding to be used for projects not connected to the fossil fuel industry.

A major point of debate in international climate talks has been whether to stop using fossil fuels entirely or only stop using "unabated" fossil fuels. At the 2023 United Nations Climate Change Conference, an agreement was made to reduce the use of "unabated" coal. The term "abated" usually means using CCS, but the agreement did not clearly define the word.

Because the terms "abated" and "unabated" were not explained, the agreement was criticized for being unclear. Without a clear definition, it might be possible to call fossil fuel use "abated" even if CCS is used only slightly, such as capturing 30% of emissions from a power plant.

The Intergovernmental Panel on Climate Change (IPCC) defines "unabated" fossil fuels as those "produced and used without actions that significantly reduce greenhouse gas emissions throughout their life cycle." For example, this includes power plants that capture less than 90% of emissions or energy systems that do not reduce methane leaks by 50–80%. The IPCC’s definition aims to require both effective CCS and major reductions in gas leaks to qualify fossil fuels as "abated."

Social acceptance

The public is not very familiar with carbon capture and storage (CCS). Among people who know about CCS, many are not very supportive, especially when compared to support for other ways to reduce emissions.

A common worry is whether information is clear, such as about safety, costs, and effects on the environment. Another reason people may accept CCS is if scientists admit that some risks are not fully understood, like possible harm to nature or health. Studies show that when projects involve communities in planning, they are more likely to succeed than projects that do not include public input. Some research suggests that working with communities can help prevent harm to people living near CCS projects.

Government programs

Most carbon capture and storage (CCS) projects currently in operation have received financial help from governments. This support usually comes in the form of grants to start projects and, to a smaller degree, subsidies to help with ongoing costs. Some countries also offer tax credits. Grants have been especially important for projects started after 2010. For example, 8 out of 15 projects received grants ranging from about USD 55 million (AUD 60 million) for the Gorgon project in Australia to USD 840 million (CAD 865 million) for the Quest project in Canada. A clear price on carbon has only helped CCS projects in two cases: the Sleipner and Snøhvit projects in Norway.

To support domestic oil production, the U.S. federal tax code has provided incentives for enhanced oil recovery since 1979. A 15% tax credit was added to the U.S. Federal EOR Tax Incentive in 1986, which led to a rapid increase in oil production using CO2 for enhanced recovery.

In the U.S., the 2021 Infrastructure Investment and Jobs Act allocated over $3 billion for CCS demonstration projects. A similar amount was set aside for regional CCS hubs that focus on capturing, transporting, and storing or using CO2. Additional funds are provided each year for loan guarantees to support CO2 transport infrastructure.

The Inflation Reduction Act of 2022 (IRA) updated tax laws to encourage CCS. Under this law, companies can receive up to $85 per tonne of CO2 captured and stored in saline geologic formations or up to $60 per tonne for CO2 used in enhanced oil recovery. The IRS checks documents from companies to prove how much CO2 is being stored but does not conduct its own investigations. In 2020, a federal review found that companies claiming the 45Q tax credit failed to document successful storage for nearly $900 million of the $1 billion they had claimed.

In 2023, the U.S. EPA proposed a rule requiring CCS to achieve a 90% reduction in emissions from existing coal and natural gas power plants. This rule would take effect between 2035 and 2040. For natural gas plants, the rule would require capturing 90% of CO2 by 2035 or using 30% low-greenhouse gas (GHG) hydrogen starting in 2032 and 96% low-GHG hydrogen starting in 2038. While the federal government may fund CCS pilot projects, local governments would likely manage the siting and construction of CCS projects. CO2 pipeline safety is overseen by the Pipeline and Hazardous Materials Safety Administration, which has faced criticism for being underfunded and understaffed.

Canada introduced a tax credit for CCS equipment from 2022 to 2028. The credit covers 50% of costs for CCS capture equipment and 37.5% for transportation and storage equipment. The Canadian Association of Petroleum Producers had requested a 75% credit. The federal tax credit was expected to cost CAD $2.6 billion over five years, but in 2024, the Parliamentary Budget Officer estimated the cost would be CAD $5.7 billion. Saskatchewan extended its 20% tax credit under the province’s Oil Infrastructure Investment Program to pipelines carrying CO2.

In Norway, CCS has been part of a strategy to align fossil fuel exports with national emission-reduction goals. In 1991, the government introduced a tax on CO2 emissions from offshore oil and gas production. This tax, along with favorable geology, led Equinor to implement CCS in the Sleipner and Snøhvit gas fields. In June 2025, Norway launched the world’s largest full-scale industrial CCS operation.

In 2022, Denmark announced up to €5 billion in subsidies for CCS, aiming to reduce emissions by 0.9 million tonnes of CO2 by 2030.

In the UK, the CCUS roadmap outlines government and industry commitments to deploy carbon capture and storage (CCUS). It plans to create four low-carbon industrial clusters that would capture 20–30 million tonnes of CO2 annually by 2030. In September 2024, the UK government announced £21.7 billion in subsidies over 25 years for the HyNet CCS and blue hydrogen scheme in Merseyside and the East Coast Cluster scheme in Teesside.

China’s State Council has issued over 10 national policies and guidelines promoting CCS, including the Outline of the 14th Five-Year Plan (2021–2025) for National Economic and Social Development and Vision 2035 of China.

Related concepts

Carbon dioxide (CO₂) can be used as a raw material to make different types of products. In 2022, about 1% of the CO₂ captured each year was used in products. For example, in the production of urea, an important fertilizer, CO₂ created during an industrial process is often reused. However, this type of reuse within the same process is not counted in carbon capture statistics. Similarly, CO₂ used in the food and beverage industry is also not included in these figures.

By 2023, it is possible to make the following products from captured CO₂: methanol, urea, polycarbonates, polyols, polyurethane, and salicylic acids. Methanol is mainly used to create other chemicals, though it may be used more widely as a fuel in the future.

Technologies to store CO₂ in mineral carbonate materials have been tested, but they are not yet ready for use in industry as of 2023. Research is ongoing to use CO₂ in concrete or building materials. Using CO₂ in construction materials could be useful for large-scale applications and is the only method that permanently stores CO₂. Other research includes creating synthetic fuels and chemicals from CO₂. Producing fuels and chemicals from CO₂ requires a lot of energy.

Using CO₂ in products does not always reduce emissions. The climate benefits depend on factors such as how long the product lasts before releasing CO₂ again, the energy used in production, whether the product would otherwise be made with fossil fuels, and the source of the captured CO₂. Using CO₂ from bioenergy instead of fossil fuels leads to greater emissions reductions.

The amount of CO₂ that can be used in products is much smaller than the total CO₂ that could be captured. For example, in a plan to reach net zero emissions by 2050, over 95% of captured CO₂ would be stored underground, and less than 5% would be used in products.

According to the International Energy Agency (IEA), products made from captured CO₂ are likely to cost more than traditional or low-carbon alternatives. One important use is to create synthetic hydrocarbon fuels, which are needed for long-haul flights alongside biofuels. Because of limited sustainable biomass, these fuels will be essential for achieving net-zero emissions. The CO₂ used must come from bioenergy or direct air capture to be carbon-neutral.

Direct air carbon capture and sequestration (DACCS) is the process of removing CO₂ directly from the air and storing it long-term. Unlike carbon capture from point sources, DACCS can remove CO₂ from non-stationary sources, such as airplane engines. As of 2023, DACCS is not part of emissions trading systems because it costs over $1000 per ton of CO₂, which is much higher than current carbon prices.