It Could Have Up to 90% Less Carbon Storage Capacity Than You Realize

Recent studies indicate that the planet may exhaust its capacity for storing captured carbon dioxide within the next 200 years, revealing that our ability to retain CO.₂ underground is significantly less than previously believed.

Government and industry advocates promote the underground storage of carbon dioxide as a viable solution to achieving net-zero emissions while still utilizing fossil fuels.

Previously estimated industry figures suggested a global geological storage capacity of about 14,000 Gigatonnes of CO.₂. However, as noted by Jori Rogelj from Imperial College London, UK, this capacity was thought to be effectively limitless.

Through comprehensive analysis, Rogelj and his team discovered that the actual available storage space might be considerably lower. By assessing stable geological formations while excluding areas with significant risk factors, such as proximity to major urban centers, sensitive ecosystems, or regions prone to earthquakes, they concluded that only 1460 Gigatonnes of geological storage capacity is viable worldwide.

“From a situation where storage options appeared virtually boundless, we’ve transformed our perspective,” Rogelj explains. “The storage potential we can depend on requires careful management and represents a crucial asset,” he continues, emphasizing that the potential is now ten times more valuable than previously recognized.

Most climate projections indicate that adequate underground carbon storage is essential for the world to attain net-zero emissions. The extent of this storage relies fundamentally on reducing fossil fuel consumption. Researchers caution that if we continue to depend on geological storage to isolate significant emissions post-net zero, we could deplete carbon storage entirely by the year 2200.

Rogelj asserts that his findings suggest underground carbon storage should only be utilized as a last resort when all other options have been exhausted. He recommends relying on zero-emissions solutions whenever feasible, rather than capturing and storing emissions from fossil fuel power stations.

This strategy would preserve underground storage capacity for CO₂ that could be utilized with technologies such as direct air capture (DAC), which extracts excess CO₂ directly from the atmosphere. DACs, along with other “negative emissions” technologies, can potentially help the world achieve net negative emissions beyond reaching net zero, opening up pathways to effectively reverse climate change.

According to Rogelj and his colleagues, the 1460 Gigatonnes of accessible underground CO₂ storage capacity could allow the world to counteract warming by as much as 0.7°C.

Nonetheless, Stuart Haszeldine from the University of Edinburgh warns that the actual usable geological storage capacity might be less than the industry’s 14,000 Gigatonnes estimate and suggests that these revised lower figures could still be overly optimistic.

He argues that the team’s approach to evaluating risk factors is “quite conservative,” pointing out that certain seismic regions, such as the North Sea, have been excluded from consideration but remain suitable for carbon isolation. “We understand enough about carbon storage and oil reserves. An oil field filled with oil, gas, or carbon dioxide can withstand quakes of magnitude 6 without any issues,” Haszeldine states.

He emphasizes that most analysts foresee carbon sequestration as an integral part of the transition away from fossil fuels. Therefore, he predicts that the volume of carbon injected underground yearly should diminish once net-zero emissions are achieved.

“[Carbon capture and storage] encompasses a wide range of climate pessimism and challenges, which have often been overlooked, explaining why we don’t really require a tremendous amount of joint CO₂ storage capacity,” Haszeldine concludes.