This article uses input-output methods to obtain the energy-related CO2 intensities for the Spanish economy in 1992. Based on those intensities, it yields a structural decomposition of Spanish energy-related CO, emissions and an estimation of the price effects of several hypothetical carbon taxes levied on fossil fuel consumption. These results are related to the ongoing discussion within EU circles and member states about the consequences of carbon,energy taxes, and to the simulated effects of such taxes in various countries. The paper also responds to the lack or reliable disaggregated data on Spanish CO2 emissions and to the growing awareness on the limited effectiveness OF Spanish climate change policies.