Overall capacity for storing carbon might be a tenth of that previously thought, according to a new study published by the International Institute for Applied Systems Analysis (IIASA) and is not a ‘way out’ of climate change.

The study predicts that carbon capture could cut global warming by 0.7C, which is a tenth that the 6C that has been touted.

The new estimates of reduced capacity, coupled with the discovery of geochemical reactions such as leaks, earthquakes and water contamination that could rule out large numbers of locations and decrease storage effectiveness, moves CCUS from a comprehensive solution to a smaller part of the whole array of weapons needed to combat climate change.

The researchers also found that natural carbon storage, trees for example, is less effective and long-lasting.

Coupled with the warming properties of ozone (see article Fixing ozone will warm planet) the emphasis on actually reducing carbon emission has recently become a higher imperative.

According to lead author Matthew Gidden, a senior researcher in the IIASA Energy, Climate, and Environment Program and at the Center for Global Sustainability at the University of Maryland, US, the study’s findings highlight the need for caution: “With this study, we can conclude that carbon storage should be treated as an exhaustible, intergenerational resource, requiring responsible management. Hard choices must be made about which countries, which sectors, and even which generations are able to utilise it. It’s critical that countries make clear in their climate action plans how they plan to use carbon storage in order to collectively achieve long-term climate goals while minimising harm to human health, biodiversity, and sustainable development.”

“This study should be a gamechanger for carbon storage. It can no longer be considered an unlimited solution to bring our climate back to a safe level. Instead, geological storage space needs to be thought of as a scarce resource that should be managed responsibly to allow a safe climate future for humanity. It should be used to halt and reverse global warming and not be wasted on offsetting on-going and avoidable CO2 pollution from fossil electricity production or outdated combustion engines,” explained coauthor Joeri Rogelj, director of research at the Grantham Institute and PM senior research scholar at IIASA.

The team has also developed an interactive website that allows policymakers, researchers, and the public to explore the findings in detail. This tool is designed to support evidence-based decision making and international cooperation on the prudent use of geological storage: https://cdr.apps.ece.iiasa.ac.at/story/prudent-carbon-storage.

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