Building efficiency background

Projected future emissions from the building sector #

The Intergovernmental Panel on Climate Change (IPCC) estimates that in 2030 global greenhouse emissions will total 55.7 Gigatons carbon dioxide equivalent or GtCO2-eq (excluding emissions from energy extraction/distribution and from peat and bog fires).

Emissions from commercial and residential buildings in that year are estimated at 14.3 GtCO2-eq or 26 percent of total emissions.

For more see Table 11.1 in Climate Change 2007: Working Group III: Mitigation of Climate Change, Chapter 11: Mitigation from a cross-sectoral perspective

Sources of building emissions #

Emissions from buildings are due to direct burning of fossil fuels and use of fossil fuel-generated electricity for heating, cooling, hot water, cooking, lighting, and appliances (including electronic devices such as computers and entertainment systems).

Commercial and residential buildings have different energy usage characteristics; similarly, the energy usage profiles of buildings in developed countries differ from those of buildings in developing countries.

For more detail, see Figure 6.3 in IPCC, Climate Change 2007: Working Group III: Mitigation of Climate Change, Chapter 6: Residential and commercial buildings

Mitigation potential #

The IPCC projects that in 2030 up to 6.4 GtCO2-eq of building emissions can be reduced at a cost of less than $100 per ton of CO2-eq and that up to 4.5 GtCO2-eq of these emission reductions can be achieved through initiatives whose long term savings exceed their up front costs.

For more see Table 6.4 in IPCC, Climate Change 2007: Working Group III: Mitigation of Climate Change, Chapter 6: Residential and commercial buildings.