It tracks the annual rates of CO2 stored by operational projects worldwide, drawing on reported data from the growing community of storage operators. This year's edition added projects in New Zealand and Italy for the first time, and recorded the start of injection at the Northern Lights project in Norway in August 2025, one of the most closely watched cross-border storage ventures in the industry. The consortium behind the Register brings together more than 30 international experts from academia, industry and government, including the Department of Energy Science and Engineering at Stanford, MIT Civil and Environmental Engineering, the Global CCS Institute, the Carbon Capture and Storage Association, IEAGHG and CSIRO.

Professor Samuel Krevor, Director of the Register from Imperial's Department of Earth Science and Engineering, said the latest report shows that geological CO2 storage has become a global enterprise, with annual reported storage more than doubling between 2016 and 2024, and the Register itself now covering 69 individual projects around the world. The consistency of these operations, he noted, and the fact that new countries and projects continue to join the Register, shows that geological storage is demonstrated as a large-scale mitigation technology. The underlying process is straightforward in principle.

Carbon dioxide captured from industrial sources and power production, or directly from the atmosphere, is injected into rocks deep underground, allowing this greenhouse gas to be safely stored for potentially thousands of years. The Register focuses specifically on tracking this geological storage pathway, and its authors note that while the sources of CO2 today are dominated by industrial capture, removals from the atmosphere are projected to emerge as the leading technology using geological storage by mid-century. That projection, made by Professor Krevor, underscores why the integrity of the storage record is expected to matter even more in the decades ahead than it does today.

The geography of the 2024 record is strikingly concentrated. Projects in the United States remain the largest contributors by number, with 23 projects reporting a combined 20.2 million tonnes, much of it governed by the accounting requirements of the Environmental Protection Agency's regulation covering CO2 injected for underground sequestration. The single largest project, however, sits in the South Atlantic: Brazil's Petrobras Santos Basin Pre-Salt Oil Field reported 14.2 million tonnes, approximately one-third of the global total.

China's reported storage increased to 1.7 million tonnes in 2024, driven primarily by the Shengli Oilfield and the newly included Daqing Aonan Oilfield, while Australia also reported 1.7 million tonnes with the addition of the Moomba project. This year's report also does something unusual for a field eager to advertise its growth: it revises its own numbers downward. Following a new interpretation of data from the North Burbank Unit to account for recycled CO2, a correction of double counting between company-level and project-level reporting, and revised national inventory figures for Sleipner, the world's first commercial CCS project, cumulative storage through 2023 has been revised from 351.4 to 342.0 million tonnes, a decrease of 2.7 percent.

The 2023 annual figure has been revised from 45.2 to 41.7 million tonnes. Dr Xiaowei Gao, Executive Director of the Register from Imperial's Department of Earth Science and Engineering, said the revisions reflect the latest evidence, and that the team has been explicit in the report about where the accounting for reported storage remains uncertain. That transparency, she argued, matters if geological CO2 storage is to earn the confidence of policymakers and investors.

At the time of publication, 29 projects across 12 countries had reported 2025 storage, with an aggregate of 36.2 million tonnes, a figure the report explicitly cautions is incomplete and should not be interpreted as a full-year global total. Brazil's Santos Basin project has already reported 19.6 million tonnes for 2025, up from 14.2 million tonnes the year before, while operations in China have reported 2.6 million tonnes across seven projects and the United States 8.9 million tonnes across six projects. Beneath the headline numbers lies a more complicated accounting problem that the Register's authors address head-on.

A large share of the reported storage, 82.3 percent of the cumulative total, is categorised as Geological Storage with Oil Recovery, much of which aims to extend the operating life of an existing oil field. Within that category, around a third of the stored CO2, amounting to 112.5 million tonnes or 32.4 percent of the cumulative total, is simply recorded as injected, potentially without adjustments for the CO2 that is later brought back to the surface and reinjected underground. The Register's response is methodological rather than dismissive.

In the report, the authors write that they endeavour to compile values of storage net of any losses and accounting for recycled and reinjected CO2, while acknowledging that there are uncertainties in the meaning of the reported values for projects with ambiguous or unstated accounting bases. An analysis of these uncertainties will be incorporated into upcoming reports. The stakes of getting the accounting right are set to grow dramatically.

Professor Krevor noted that to meet the 1.5 degrees Celsius target pledged under the Paris Agreement, all projections indicate that geological CO2 storage must scale up to one billion tonnes of CO2 storage or more per year by 2050, roughly twenty-five times the 2024 record. The more precisely every tonne of CO2 can be traced from injection to permanent storage, he argued, the stronger the evidence base the community can provide as the technology grows to the scale that climate targets demand.

Subject of Research: Global geological CO2 storage rates and accounting as tracked by the London Register of Subsurface CO2 Storage

Article Title: Global underground CO₂ storage hits record 43.6 million tonnes as London Register expands reach

Article References: Global underground CO₂ storage hits record 43.6 million tonnes as London Register expands reach. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: carbon capture and storage, geological CO2 storage, London Register, Imperial College London, CCS, climate mitigation, CO2 sequestration, Sleipner, Northern Lights, Petrobras Santos Basin, carbon accounting, Paris Agreement