Injection of large quantities of CO2 into underground reservoirs where it can be securely and permanently stored can be successfully achieved with economic incentives to accelerate field-scale applications of CO2 sequestration. Significant advances in site characterization, monitoring, leak assessment and management occurred in the past 10 years. Legal and regulatory protocols have also been put into place in the US. Over time, leakage risk decreases while permanence of the storage increases, however the effectiveness of a site to securely store CO2 at geological time scale is very difficult to define. Moreover, uncertainties persist over the liabilities of parties after the site is closed. Nevertheless, scaling-up and worldwide deployment and coordination of these technologies and strategies should be the focus for next years. Since high purity CO2 streams are required for storage, future research will also have to address ways to reduce the cost of CO2 capture and sequestration processes to be cost-competitive with other carbon-free options.