Minimising greenhouse gas emissions from fossil fuels

Combustion of fossil fuels is the main anthropogenic source of carbon dioxide, the principal greenhouse gas. Generation of electricity is the single largest user of fossil fuels, world-wide. Thus technologies which could reduce or eliminate greenhouse gas emissions associated with the production of electricity from fossil fuels will be important, if the world needs to make substantial reductions in greenhouse gas emissions. Already the Intergovernmental Panel on Climate Change has indicated that there are discernible signs of human interference with the world's climate. If there is international agreement about the need to make substantial reductions in greenhouse gas emissions, then having access to suitable, effective technology would be important. This would help avoid the need for precipitate action, such as radical changes in the energy supply systems. Capture and disposal of greenhouse gases from flue gases can achieve substantial reductions in greenhouse gas emissions. This can be realised with known technology. Such technology has been investigated by the EEA Greenhouse Gas R&D Programme, an international collaborative activity. Its work has shown that capture of CO2 from flue gases is technically feasible, although at substantial cost. The gas would have to be sequestered for several hundred years and there are a number of feasible ways of doing this. Storage of CO2 is relatively inexpensive, compared with the cost of capturing the gas in the first place. However, there are significant uncertainties involved in most of these schemes, indicating the need for further research and development in order to reduce the risks of their application. In this paper, the range of options will be summarised and steps needed to achieve further progress will be identified. Emissions of other gases, such as methane, are also expected to influence the climate. Methane is emitted from many anthropogenic sources; the IEA Greenhouse Gas programme is investigating ways of reducing these emissions. Opportunities for abatement of methane emissions associated with coal mining will be described. Reduction in emissions from drainage gas is relatively straightforward and can, in appropriate circumstances, generate useful income for the mine operator. More substantial amounts of methane are discharged in mine ventilation air but these are more difficult to deal with. In this paper, a summary will be given of recent progress in reducing methane emissions. Opportunities will be examined for further research to progress these technologies.