Mitigation from a cross sectoral perspective

The economic potentials for GHG mitigation at different costs have been reviewed for 2030 on the basis of bottom-up studies. The review confirms the Third Assessment Report (TAR) finding that there are substantial opportunities for mitigation levels of about 6 GtCO2-eq involving net benefits (costs less than 0), with a large share being located in the buildings sector. Additional potentials are 7 GtCO2-eq at a unit cost (carbon price) of less than 20 US$/tCO2-eq, with the total, low-cost, potential being in the range of 9 to 18 GtCO2-eq. The total range is estimated to be 13 to 26 GtCO2-eq, at a cost of less than 50 US$/tCO2-eq and 16 to 31 GtCO2-eq at a cost of less than 100 US$/tCO2-eq (370 US$/tC-eq). As reported in Chapter 3, these ranges are comparable with those suggested by the top-down models for these carbon prices by 2030, although there are differences in sectoral attribution (medium agreement, medium evidence).