Author name: Michael A. Arthur

Carbon dioxide capture and sequestration (CCS) in deep geological formations has recently emerged as an important option for reducing greenhouse emissions. If CCS is implemented on the scale needed to make noticeable reductions in atmospheric CO2, a billion metric tons or more must be sequestered annually—a 250 fold increase over the amount sequestered today. Securing such a large volume will require a solid scientific foundation defining the coupled hydrologic–geochemical–geomechanical processes that govern the long-term fate of CO2 in the subsurface. Also needed are methods to characterize and select sequestration sites, subsurface engineering to optimize performance and cost, approaches to ensure safe operation, monitoring technology, remediation methods, regulatory overview, and an institutional approach for managing long-term liability.

Human and industrial development over the past hundred years has led to a huge increase in fossil fuel consumption and CO2 emissions, causing a dramatic increase in atmospheric CO2 concentration. This increased CO2 is believed to be responsible for a significant rise in global temperature over the past several decades. Global-scale climate modeling suggests that the temperature increase will continue, at least over the next few hundred years, leading to glacial melting and rising sea levels. Increased atmospheric CO2 also leads to ocean acidification, which will have drastic consequences for marine ecosystems. In an attempt to solve these problems, many have proposed the large-scale sequestration of CO2 from our atmosphere. This introductory article presents a summary of some of the evidence linking increasing atmospheric CO2 concentration to global warming and ocean acidification and our efforts to stem this rise though CO2 sequestration.