To meet targets for greenhouse gas emission reduction set by the Kyoto Protocol, many countries are considering a range of near-term options such as, fuel switching, energy efficiency improvements and use of renewable sources of energy, to reduce their greenhouse gas emissions. However, to meet the goal of the UN Framework Convention on Climate Change, namely stabilization of greenhouse gas concentrations in the atmosphere, it is likely that deeper reductions in emissions will be needed. This will require additional measures such as the geological storage of CO2. Geological storage of CO2 would be used to sequester CO2 captured from large anthropogenic sources, such as power and large industrial plants. There are a number of reservoirs suitable for geological storage of CO2 including depleted oil and gas fields and deep saline aquifers. Many of these reservoirs have stored hydrocarbons and fluids for million of years, which gives confidence that CO2 can be stored for similar durations, but research is needed to confirm this.
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Carbon dioxide (CO2) is the main compound identified as affecting the stability of the Earth’s climate. A significant reduction in the volume of greenhouse gas emissions to the atmosphere is a key mechanism for mitigating climate change. Geological storage of CO2, or the injection and long-term stabilization of large volumes of CO2 in the subsurface in saline aquifers, in existing hydrocarbon reservoirs or in unmineable coal seams, is one of the more technologically advanced options available. A number of studies have been carried out and are reported here. They are aimed at understanding the safety, physical and chemical behaviour and long-term fate of CO2 when stored in geological formations. Until efficient, alternative energy options can be developed, geological storage of CO2, the subject of this volume, provides a mechanism to reduce carbon emissions significantly whilst continuing to meet the global demand for energy.