Estimates of GHG emission reduction potential by country, sector, and cost

In this study, emission reduction potentials in greenhouse gases (GHG) are assessed by country, sector, and cost using a GHG emission reduction assessment model with high resolutions with respect to region and technology and high consistency in terms of assumptions, interrelationships, and solution principles. Model analyses show that large potential reductions can be achieved at low cost in developing countries and power sectors. In addition, cost-efficient emission reductions were evaluated for some international emission reduction targets that have been derived on the basis of the principle of common but differentiated responsibilities among developed and developing countries. If (1) emission reduction measures at negative costs and below 50 $/tCO2 for developed countries, (2) intensity improvement measures for selected sectors at negative costs and below 20 $/tCO2 for major developing countries, and (3) all emission reduction measures with negative costs for other developing countries in 2020 are adopted, then emission reductions of 8.9, 14.8, and 27.7 GtCO2 eq./yr compared to the technology-frozen case can be expected in developed countries, major developing countries, and globally, corresponding to a 11% decrease, 40% increase, and 17% increase from 2005 levels, respectively. Large-scale emission reductions can be achieved even if CO2-intensity targets for major sectors are assumed for major developing countries.