computable general equilibrium model with specific detail in taxation and energy use is developed in this paper to quantify the impact of the implementation of energy taxation to reduce carbon dioxide emissions in Ireland. Benchmark data combining physical energy and emissions data and economic data in the form of a Social Accounting Matrix (SAM) had to be compiled from various data sources, because energy and pollution accounts from the SEEA are not available for Ireland. We find that the reduction target for energy related CO2 emissions in Ireland of 25.8% compared to 1998 levels can be achieved with a carbon energy tax of 10¿15 euros per tonne of CO2. Though fuel switching is important in meeting the target, this result is more sensitive to the possibilities for producers to substitute away from energy use. Welfare would fall but only by small percentages. Production and consumption patterns would change more significantly, with a shift in demand from fuels with a high emission factor to energy sources with a lower carbon-intensity and from energy to other commodities. This paper confirms that a carbon energy tax leads to greater emission reductions than an equivalent uniform energy tax. The latter has a stronger negative impact on the less polluting energy sectors whereas the carbon tax greatly stimulates the use of renewable energy and reduces the use of peat and coal. The new SAM, the model and the application to energy taxes contribute to a better informed debate on environmental policy in Ireland.