Global leaders are banking on tech advances to solve climate change.
One leading idea is to capture carbon pollution from the air and then bury it underground forever.
It may sound practical.
There is no conceivable way it can work.
Global leaders are banking on tech advances to solve climate change.
One leading idea is to capture carbon pollution from the air and then bury it underground forever.
It may sound practical.
There is no conceivable way it can work.
False Promises
Why carbon capture and storage won’t fix our climate crisis.
Carbon Captured How the fossil fuel industry influenced climate research
An investigative series by ProPublica and Drilled
For more than 40 years, oil companies have been funding research at prestigious universities into climate change “solutions” that would not require the public to stop using oil and gas. Among their favored fixes is carbon capture and storage.
An investigation by ProPublica and Drilled has found that boosters of CCS have ignored evidence of the technology’s limitations, or overstated its potential, and convinced the world it could be effective.
They’ve promoted this idea despite the fact that for CCS to work at the scale now envisioned, the world would need to devote almost unimaginable resources. Even if that were done, it might still prove impossible to trap so much carbon dioxide inside the earth.
Optimism has reigned, however, because small tests have worked and because slow global response to climate change has left few other options.
storage
In 2008, the International Energy Agency projected that to stave off dangerous levels of warming, we would have to be burying around 1.6 billion tons, or 1,600 megatons, of CO2 per year by 2025.
Since then, its optimistic projections have continued.
But deployment of the technology has never come close to those ambitions.
Right now, globally, we’re permanently burying less CO2 than a single large power plant can emit in a year.
Some experts point to the CO2 that gets pumped into the ground to help extract oil as proof CCS works. But that process, called enhanced oil recovery, isn’t designed to function the same way and isn’t monitored as stringently.
Global leaders are betting on carbon capture working now more than ever.
The models used in the latest United Nations assessment presume the technology succeeds.
IEA representatives and U.N. modelers say their projections reflect what the world has to do to achieve its goals of averting extreme warming.
To make CCS work, we would need to capture CO2 pollution in four ways:
Trap it from smoke stacks.
Absorb it from the air with fast-growing grasses or trees,
then capture it from those plants when they are burned for fuel.
Scrub it from the air, often using giant fans.
Then we would pump all of it into porous rock deep beneath the earth’s surface.
The U.N. analysis now suggests that countries must inject 6 billion tons of CO2 underground each year by the middle of the century.
Getting 6 billion tons of CO2 a year out of the atmosphere, though, is a daunting task.
Imagine the neighborhoods and parks near oil, gas or coal-fired industrial plants.
We would need to add equipment to capture the CO2 from each facility, in some cases doubling its land footprint.
And we would need to devote about 768,000 square miles of land worldwide to growing those carbon-absorbing plants.
That would cover an area roughly the size of Mexico — and compete for valuable land used to grow food or sustain forests.
If all of this works, and the CO2 is successfully captured, it must then be moved to a place where it can be buried.
In the U.S. alone, this could require building more than 68,000 miles of new pipelines in a little more than two decades.
That’s more than double the distance to fly around the earth.
And longer than the country’s entire interstate highway system.
Globally, pipelines could tally in the hundreds of thousands of miles.
To cross the oceans, we would need at least 85 specially built tankers to move the high-pressured gas. As of April, there were only three ships in the world equipped to do that.
Then, there is the challenge of finding a place to put 6 billion tons of CO2 a year.
Today, just 12 large-scale geologic reservoirs have attempted to permanently store CO2 pollution — but we would need more than 2,000 reservoirs of that size for CCS to work, each requiring years of study and engineering before it could be used.
That means we would need to open a brand new geological waste site somewhere on the planet every four days for the next 25 years.
Every site would need constant monitoring for decades to ensure the CO2 doesn’t leak.
Even if this could be done, it would cost tens of trillions of dollars.
Right now, U.S. taxpayers are paying oil and gas companies $85 for every metric ton they put underground.
At that rate, by 2050, the world could be spending half a trillion dollars — more than China’s military budget, and 10 times more than the U.N.’s humanitarian and development aid budget — each year.
$500 billion
annual global expenditure on carbon capture and storage by 2050
$340 billion
China’s military budget in 2025
$50 billion
U.N.’s humanitarian and development aid budget in 2024
The few test sites that exist suggest that keeping carbon underground may not work at scale.
Since 1996, while the 12 large-scale geological storage projects have opened, plans for another 12 have been scrapped. Many CCS sites in operation — in Norway, Algeria, Australia and the U.S. — have been mired in problems, pointing to enormous challenges ahead.
Some rock layers can hold far less CO2 than experts have estimated.
Finicky pipes and injection systems can get clogged or break down.
The rock that seals CO2 in place can crack, risking a leak. In one instance, injected CO2 caused the ground above it to bulge.
In another instance, CO2 escaped from an old oil industry well nearby.
Thorough, long-term monitoring can be expensive, but without it, such leaks could be missed.
Climate experts know about the costs, technical troubles and failures of CCS test projects.
Yet many of them have continued to boost the technology, even as they have downplayed solutions showing greater progress.
For example, the same modelers who overestimated the potential of geological carbon storage repeatedly underestimated solar power — one of the energy technologies that would allow more oil to remain in the ground.
Over the last several decades, solar power is the technology that has thrived.
Carbon capture and storage remains elusive.
Notes on Data Sources
The modeled pathways, what we call projections, for deployment of carbon capture and storage are from text and tables in the International Energy Agency’s Energy Technology Perspectives and World Energy Outlook reports, and from correspondence with the IEA. The 2008 and 2010 projections are from the IEA’s Blue Map scenario; a second 2010 projection is from the Net Zero by 2050 scenario; 2018 is from the Sustainable Development scenario; and 2021, 2022, 2023 and 2024 are from the Announced Pledges, Stated Policies and Net Zero by 2050 scenarios. Some of these scenarios represent pathways designed to achieve a specific temperature or concentration of CO2. Other scenarios represent what is possible based on current policies or pledges. Pathways from years where underlying data was not provided in the IEA’s report were excluded.
In response to emailed questions, a spokesperson for the IEA said, “The IEA’s long-term modelling and scenarios are not designed to predict future deployment of technologies; the different scenarios we produce are intended to explore the potential implications and trade-offs of different policy, technology and investment choices.” The agency said that solar power has succeeded in part because of successful policy support for it, especially in China, and that CCS has lagged because of a lack of similar support. It added that CCS remains a part of the solution portfolio for industries that might otherwise be hard to decarbonize. The spokesperson noted that a record number of CCS projects are under construction.
Data for the actual CCS capacity derives from the IEA’s CCUS Projects Database. We defined large-scale projects as those with the estimated capacity to store at least 500,000 metric tons of CO2 annually. The data comprises only projects that were completed and that permanently store CO2, rather than those that utilize CO2 for enhanced recovery of oil and gas or other uses, since those uses can create more carbon than they store or have looser requirements for monitoring.
Of the 12 completed CCS injection projects, 11 remain operational and one has been decommissioned. The annual total for carbon stored assumes the projects operated at their stated capacity each year since launch, which few have done. The comparison to the volume of CO2 emitted by a single large power plant is derived from data provided by the U.S. Energy Information Administration.
The projections for solar power production are from the IEA’s World Energy Outlook reports. Data depicted is from the Announced Pledges, Current Policies, New Policies, Net Zero by 2050, Reference, Sustainable Development and Stated Policies scenarios. Data was limited to projections from IEA reports from every other year to make the chart less cluttered.
Data for the actual deployment of solar energy was taken from IEA’s World Energy Outlook and Energy Technology Perspectives reports.
Data comparing projections and deployment of carbon storage and solar energy was initially compiled by researchers Rory French and Lindsey Gulden.
The 6 billion tons target figure is derived from the 2024 paper “The feasibility of reaching gigatonne scale CO2 storage by mid-century.” It reflects the median quantity of subsurface carbon storage among scenarios from the Intergovernmental Panel on Climate Change’s Sixth Assessment Report scenario database that have a greater than 67% chance of limiting warming to 2°C.
The IPCC said it does not develop or run the models that create the scenarios in its database, and noted that the Assessment Report includes information contextualizing and questioning the models’ assumptions around solar and CCS deployment.
The estimate of 768,000 square miles of land needed to grow biomass comes from the Sixth Assessment Report’s Technical Summary, which states that the cropland area needed to keep warming below 1.5°C with no or limited overshoot is around 199 million hectares in 2050.
The estimate of 68,000 miles of pipeline is sourced from the 2021 Net-Zero America report.
To calculate how many large-scale CCS reservoirs would be required to meet the 6 billion metric tons target, we assumed the projects would bury as much as the largest carbon storage project has in its largest year, the Gorgon Carbon Dioxide Injection Project in Australia, which injected 2.7 million tons in 2019. That figure came from the 2025 annual report from the London Register of Subsurface CO2 Storage, produced by Imperial College London.
To calculate the total annual cost for CCS projects by 2050, we multiplied the $85-per-ton subsidy the U.S. offers industry in its 45Q tax credit by 6 billion tons.
China’s 2025 military budget is sourced from the Stockholm International Peace Research Institute.
The U.N.’s humanitarian and development aid budget for 2024 comes from the U.N. Systems Chief Executives Board for Coordination’s expenses factsheet.