From government policies to corporate boardrooms, the fight against climate change is driving a global push toward net-zero emissions. At the center of it all is carbon dioxide (CO₂), a colorless, odorless greenhouse gas that has played a central role in Earth’s warming since the dawn of the industrial age. As temperatures continue to climb, cutting carbon emissions is now a global priority. And new technology like carbon capture and storage (CCS) are gaining traction, offering ways to trap CO₂ at the source or suck it straight from the air — not only slowing its effects but actually reversing them.
Carbon Capture and Storage (CCS) Definition
Carbon capture and storage (CCS) is a technology designed to keep carbon dioxide out of the atmosphere by capturing it as it’s created — during industrial processes and power generation — for long-term storage, typically thousands of meters deep in geological formations.
Carbon capture and storage has become a key tool for achieving near-term emissions goals without requiring a complete infrastructure overhaul — especially for industrialized nations. However, despite the push from big oil companies to frame it as a climate solution, experts caution that CCS was never meant to be a standalone fix. It’s a patch that currently captures only a fraction of emissions, with much of the stored carbon being used to boost oil extraction rather than permanently contain it.
What Is Carbon Capture and Storage?
Carbon capture and storage, or CCS, is a technology that collects CO₂ emissions at industrial sites like power plants and factories, trapping them before they enter the atmosphere. The carbon dioxide is then stored somewhere it can’t do harm, typically deep underground. This method is primarily deployed in high-emission industries like power generation and chemical production, where switching to cleaner alternatives would be difficult and costly.
How Carbon Capture and Storage Works
At a high-level, carbon capture and storage follows a three-step process: capture, transport and storage.
- Capture: First, the greenhouse gas is separated at the source using chemical solvents, filters or oxygen-rich combustion to separate it from other gases.
- Transport: From there, the carbon is compressed into a dense, fluid-like state and transported, most often through pipelines.
- Storage: Once it reaches a storage site, the CO₂ is injected deep underground into naturally porous rock formations, like depleted oil fields or deep saline aquifers. These formations are sealed with thick, impermeable cap rock layers that (theoretically) can keep the carbon trapped for hundreds of thousands of years.
If done correctly, the carbon dioxide stays locked away indefinitely — mimicking the same natural processes that once stored fossil fuels in the first place.
How Is Captured Carbon Transported?
Carbon dioxide captured through CCS is typically transported through pipelines after being compressed into a dense, liquid-like state to reduce its volume and make it easier to handle. Currently, there are more than 5,000 miles of high-pressure pipelines throughout the United States, linking industrial sites to storage locations.
In cases where pipelines are not practical — such for short distances or pilot projects — carbon dioxide can also be transported by ship or truck, though these options pose higher safety risks. With that being said though, there’s no completely risk-free way to transport CO₂, as all methods come with a potential for leaks.
Where Is Carbon Dioxide Stored?
Captured carbon dioxide is primarily injected at least 800 meters underground into deep geological formations. The most common sites include depleted oil and gas reservoirs or saline aquifers, where CO₂ can remain trapped under layers of impermeable “cap rocks” for up to 100,000 years. Man-made storage sites like abandoned coal mines, salt caverns and steel tanks are also used.
Researchers are exploring other methods as well. For example, basalt formations are being tested for mineralization-based storage, where carbon solidifies into solid rock over time. Shale reservoirs are being tested as a potential option, too, but are not being used commercially yet. Deep-sea storage has also been explored, particularly off the European and Australian coasts.
Benefits of Carbon Capture and Storage
Reduces Carbon Emissions
CCS enables large-scale reduction of carbon dioxide emissions from industrial sectors that are otherwise difficult to fully decarbonize. Globally, this method could help cut up to 15 percent of annual greenhouse gas emissions by 2070, according to the International Energy Agency, and is deemed essential to the “credible pathways to 1.5°C.”
Makes ‘Negative’ Emissions Possible
Beyond simply reducing emissions, CCS combined with bioenergy (known as BECCS) can remove carbon dioxide from the atmosphere, and actually put carbon emissions into the negative. Projects like the Drax Power Station in the UK are drafting plans to capture millions of tons of carbon dioxide each year by pulling carbon out of the air. Similar negative emissions tech is emerging around the world, including forest biomass plants and agricultural waste conversion, as a way to balance out unavoidable emissions and help reverse climate change.
Uses Existing Infrastructure
CCS works alongside existing fossil fuel plants and industrial facilities, capturing carbon as it’s produced so those operations don’t have to completely overhaul their methods or shut down entirely. This so-called “bridge” role is especially important in locations where renewables aren’t as widespread yet, or in industries that can’t help but emit carbon, such as cement and steel production.
Job Creation
Building out carbon capture and storage infrastructure doesn’t just cut emissions, it also creates jobs. From engineers to construction crews to monitoring specialists, the push for large-scale CCS projects could generate anywhere between 390,000 to 1.8 million jobs, according to a National Energy Technology Laboratory report. Given that there are tens of thousands of miles to roll out over the next few decades, the number of jobs is likely to keep climbing as the industry grows.
Challenges of Carbon Capture and Storage
High Cost
Compared to other carbon reduction strategies, CCS is quite expensive. Depending on the source and method used, the cost of capturing and storing carbon dioxide can range from $50 to $150 per metric ton — a price tag that calls its economic viability into question. For example, the Petra Nova project in Texas, once the largest CCS power project in the U.S., was shut down in 2020 due to Covid-induced low oil prices and high operating costs.
Public Safety Concerns
When it comes to transporting and storing CO₂, no method is completely leak-proof. And if a site is compromised, the health hazards can be severe. Because carbon dioxide is heavier than oxygen, a leak can create a dense gas cloud that displaces breathable air. High concentrations may settle in low-lying areas, posing serious risks such as dizziness, unconsciousness, carbon dioxide poisoning, or even death by asphyxiation. It can also disable gas-powered vehicles, slowing emergency response efforts. For example, in 2020, a pipeline rupture in Mississippi released a CO₂ plume that hospitalized dozens of people, some of whom lost consciousness.
Aside from the immediate dangers, leaks essentially undo the entire purpose of CCS, releasing captured greenhouse gases back into the atmosphere and potentially wiping out years of climate progress. They can also pollute underground water sources, turning them acidic and leaching toxic metals like lead and arsenic from surrounding rock. On top of that, pumping CO₂ deep underground can shift pressure near fault lines and trigger small earthquakes — a rare but real risk that’s already been documented in some injection projects.
Most Projects Still Serve Big Oil
One oft overlooked detail about carbon capture and storage is that it’s primarily used to pump more oil out of the ground. Most projects are built around enhanced oil recovery, where the captured greenhouse gas is injected into wells to force out more fossil fuel. In fact, more than 80 percent of the carbon stored globally has been used for this purpose — not for permanent storage. Critics argue it undercuts the entire point of the method, calling it a step forward and two steps back at a time when we need to move toward cleaner energy.
Long-Term Uncertainty
Even if carbon dioxide is stored underground, there are still questions about how long it’ll stay there — and whether it might leak out in the future. Geological storage sites are promising, but they’re not foolproof. At the In Salah project in Algeria, scientists had to stop operations when they saw signs of pressure building up and the rock layers shifting. While studies overwhelmingly support natural storage sites as safe and viable, it’s going to take long-term monitoring and clear accountability to make sure it stays that way.
The Future of Carbon Capture and Storage
The path forward for carbon capture and storage hinges on scaling current infrastructure while developing newer, more flexible technologies. It’s hard-to-decarbonize industries like chemical manufacturing and cement production, where clean alternatives are still maturing, and CCS may serve as a limited, stopgap tool to curb emissions — especially as governments scramble to figure out how to stay within the 1.5- degree threshold determined by a scientific consensus in the Paris Agreement.
In order to meet net-zero emissions by 2050, the U.S. Department of Energy has announced plans to fund regional carbon capture hubs, scale up direct air capture projects and support CCS pipeline construction, with a goal to capture 1.8 billion metric tons of carbon dioxide annually. The United States alone would have to scale its carbon dioxide pipeline network by 68,000 miles, according to the Carbon Action Alliance. One step in that direction is projects like Petra Nova, a post-combustion carbon capture facility that’s designed to sequester 1.4 million metric tons of carbon dioxide per year.
Other countries are investing, too. Norway’s Northern Lights project is a first-of-its-kind, cross-border project that can transport and store 1.5 million metric tons of captured carbon dioxide annually from industrial sites across Europe, with plans to scale to 5 million. In the United Kingdom, hubs like the East Coast Cluster and HyNet North West will capture emissions from carbon-intensive industries only to transport them to offshore storage sites beneath the North Sea.
Technologies like direct air capture — which pulls carbon dioxide directly from the atmosphere — and modular CCS units designed for smaller, distributed industrial sites are in the works as well. However, both approaches still face high energy demands and financial hurdles that limit large-scale deployment. Luckily, global climate policies and carbon markets — including the U.S. 45Q tax credit and the EU Emissions Trading System — are starting to make carbon capture more financially viable. Still, it’s important that big oil companies and policymakers understand that the role of CCS is best understood as a complement to deep emissions cuts, not a replacement for systemic change.
Frequently Asked Questions
Is CCS the same as carbon offsetting?
No; carbon capture and storage reduces carbon emissions by directly capturing and storing them at the source or from the atmosphere, whereas carbon offsetting is when a company pays into another entity — whether it be a company or project — to offset their carbon footprint rather than reducing it themselves.
Is carbon capture safe?
Carbon capture is generally considered safe, but poor site selection or inadequate monitoring can increase the risk of leaks, water contamination or even small earthquakes.
How much CO₂ can we realistically store?
Scientists estimate the Earth has enough underground capacity to store thousands of gigatons of carbon dioxide. By 2050, experts project we may be able to store around five to six gigatons per year — a massive scale-up from today’s capacity of about 50 million tons annually.
Can CCS be used in vehicles or homes?
Not at this time. The technology has not been developed enough to operate on such a small scale just yet.
Is carbon capture bad for the environment?
While carbon capture and storage is widely regarded as safe, the method carries some significant environmental risks, especially in the event of carbon dioxide leaks or groundwater contamination.
Why are people against CCS?
Some people are against using CCS because it is expensive, energy-intensive and primarily used to extend fossil fuel production rather than replace it.
Does CCS really work?
Yes; carbon capture and storage has shown it can effectively trap large amounts of the greenhouse gas from factories and power plants, with several big projects already in operation around the world.
