Carbon (dioxide) capture and storage (CCS) has been proposed as a potential solution to reduce Australia’s greenhouse gas emissions. Greenhouse gases cause a warming of the Earth’s atmosphere. The most abundant greenhouse gas is carbon dioxide (CO₂). The current concentration of CO₂ in the atmospheric far exceeds the natural range over the last 650,000 years. The main source of increased CO₂concentrations is human-induced fossil fuel emissions.

To meet the United Nations Framework Convention on Climate Change (UNFCCC) goal of stabilisation of anthropogenic greenhouse gas emissions, to which Australia is signatory, deep reductions in greenhouse gas emissions are required. There is growing political and industrial support for the technology of carbon capture and storage (CCS) in the belief that it can achieve the deep cuts required in CO₂ emissions.

CCS is a technology aimed at reducing greenhouse gas emissions from burning fossil fuels during industrial and energy-related processes. It involves the capture, compression, transport, long-term storage and monitoring of CO₂, that would otherwise be released to the atmosphere.
The advantage of CCS is that widespread use of this technique could achieve significant emissions reductions without the need for rapid change in the energy supply infrastructure.

Although both government and industry are placing considerable emphasis on CCS as the key emissions reduction strategy, there are limitations to the extent to which CCS can realistically reduce emissions in Australia, and indeed globally. While each separate part of the CCS process chain has been demonstrated, complete, full-chain CCS has not yet been proven. Fully integrated CCS is currently an immature technology that is unlikely to be operational on a commercial scale for a decade or more.

Research suggests that Australia can realistically store a maximum of 25% of our total annual net emissions through geological storage of CO₂ (geosequestration). CCS should therefore be considered as a promising but still somewhat unproven option. However, it is likely to come at a significant cost, and is unlikely to make a meaningful contribution for well over a decade.

No single technology provides the solution to economically cutting carbon-dioxide emissions from fossil fuel combustion. There are many ways in which CO₂ emissions can be reduced, such as improving energy efficiency and switching to renewable and low-carbon methods of electricity generation. However, most scenarios suggest that these steps alone will not achieve the required reductions in CO₂ emissions. Carbon capture and storage (CCS) will therefore be only one of a suite of solutions needed to reduce Australia’s greenhouse gas emissions.

If the potential of CCS is to be realized, the technique must be safe, environmentally sustainable, cost-effective and capable of being broadly applied. For CCS to achieve its potential as an emissions abatement tool, several hundreds to thousands of CO₂ capture systems would need to be installed over the coming century. The actual implementation of CCS is likely to be lower due to factors such as environmental impacts, risks of leakage and the lack of a clear legal framework or public acceptance.

In the long-term, the world's energy system may have to be based on non-fossil energy sources. Decarbonising the use of fossil fuels, by capture and storage of CO₂, may help the transition to a future carbon-free energy system.

This paper examines the current and future capability of CCS to reduce Australia’s greenhouse gas emissions.