At the 2008 summit in Hokkaido, Japan, and again this summer in L'Aquila, Italy, G-8 leaders called for a 50 percent reduction in greenhouse gas (GHG) emissions by 2050 in order to avert the most serious dangers from global climate change. Improving the energy efficiency of buildings is essential: The International Energy Agency (IEA) has estimated that meeting the G-8's emission-reductions goal will require reducing annual GHG emissions from the building sector by 8.2 billion tons by 2050 below business as usual. While previous studies have shown that the cost of emissions abatement in the buildings sector is cheaper than in many other sectors, few studies have attempted to model what policies will be required to reduce building-sector emissions in line with the IEA's calculations.
Trevor Houser, expanding on his earlier PIIE policy brief, uses the World Business Council for Sustainable Development's (WBCSD) model to study the economics of improving building-sector energy efficiency. Houser agrees with previous studies that the GHG abatement costs of improved building efficiency are cheaper than the abatement costs in other sectors (though more expensive than previous studies suggest), but he finds significant barriers to investments in energy efficiency. A carbon price alone-a key part of any successful climate policy-will not be enough to overcome these barriers, and complementary measures, such as improved financing approaches and enhanced standards and codes for building energy efficiency, will be needed to incentivize long-term building-sector investments and to meet the emission-reductions goals outlined by the IEA. Failure to enact such policies, and thus to take advantage of lower cost GHG abatement opportunities in the building sector, will force greater emission reductions in other sectors and will carry a much higher price tag.