The I-O table for Northern Ireland (NIIO hereafter) used in this analysis is based on 2005 data and is an updated and further disaggregated version of the 2002 table generated by Wu and Keatley (2009). Due to the importance of agri-food sectors in the local economy, the table includes 9 agricultural sectors, 10 foods and drink processing sectors, 9 energy sectors and 4 other sectors including forestry. The vector of emission-coefficients is derived from GHG inventory data for Northern Ireland (Thistlethwaite and Jackson 2009) that is redistributed to reflect the level of disaggregation in the economic model. Land use change emissions and sequestration from cropland and grassland are distributed amongst agricultural sub-sectors2 and changes in forestland attributed to the forestry sector, the only sector in the model to exhibit negative GWP coefficients. Emission intensity in Global Warming Potential (GWP) and by selected GHG emissions for each economic sector included in the NIIO are reported in Table 1.
Measured in GWP per million pound output, electricity generation using fossil fuels (coal, oil and gas) and land based agricultural sectors (cereals, sheep, cattle and potatoes) are among the highest, while forestry has a significant carbon sink effect. Compared to the electricity generation sectors, agriculture sectors are not significant in carbon emissions (except sea fishing) but significant in methane (cattle and sheep) and nitrous oxide emissions (land based sectors). The policy approach will matter in terms of what sectors of the economy are most affected by abatement initiatives. If the focus is on carbon emissions only, there will be a much smaller impact on the agri-food sector than if more gases are included.