Global limit on carbon storage capacity in geological formations estimated

The recently published work by Gidden et al. clearly exposes the limits of carbon storage in potential geological repositories.

The authors do not include the emissions costs associated with transforming CO2 into a state easily transportable to the repositories, which reduces the sequestration potential of this technique by 30–50% [see this paper for more details]. Taking these costs into account would have further highlighted the limited value of geological CO2 storage.

The authors clearly describe the implications of this technology, including potential environmental effects, and use a well-defined methodology to clearly delineate the limits of geological CO2 storage.

The development and implementation of technologies such as geological CO2 storage, or similar technologies such as large-scale wood burial [see Bravo's commentary published as an eLetter], seek to solve a complex problem with a "magic bullet" that avoids confronting the need for a global reduction in CO2 emissions and the intensive use of solutions tailored to each local context. In short, this well-planned and developed work by its authors highlights the limitations of geological storage-based CO2 sequestration that would be involved if large-scale engineering solutions were applied, which would lead to emissions from both the capture and transport of CO2 to the reservoirs. Instead, it seems more appropriate to promote the implementation of a diverse set of nature-based solutions to reduce CO2 emissions globally.