Vattenfall - Emission, business-as-usual

Emissions in the buildings sector, business-as-usual

The direct and indirect emissions from the buildings sector were 8.2 Gt CO₂ in 2002, which corresponded to 21% of total emissions. 77% of this originated from the use of primary energy and 23% came from electricity use. The direct emissions from the sector, e.g. disregarding emissions from generation of electricity and heat used within the buildings sector, was about 3.2 Gt CO₂e or 8% of global emissions. The buildings sector consists of two sub-sectors, residential and commercial. Each of these two sub-sectors has been analysed bottom-up on a country-per-country basis. Within the buildings sector as a whole, emissions of CO₂ originate from space heating and ventilation, lighting and water heating in the first place. The residential sub-sector represents 76% of energy consumption but only contributes to 63% of the emissions. The reason is that a large share of the energy use, especially in developing countries, is traditional biomass used for cooking and heating. This biomass is assumed to be approximately carbon neutral due to re-growth. The commercial sector, which stands for 24% of consumption, correspondingly contributes to 37% of emissions. The developed world is responsible for the vast majority of the emissions within the buildings sector. Another important actor is China, where 11% of the CO₂-emissions originate. In a business-as-usual (BAU) scenario, energy consumption in the building sector is expected to grow 50% until 2030 to 14 Gt CO₂e (4.4 Gt CO₂e in direct emissions), with a shift towards electricity driving 70% of the increase in emissions. This is due to the higher carbon intensity of electricity supply relative to primary energy. Within the residential sub-sector, 44% of the energy consumption in 2030 is expected to originate from space heating. The second largest segment is water heating. Current CO₂ emissions of 5.2 Gt are expected to increase to 9 Gt under BAU and at 6 Gt with realized abatement opportunities in 2030. A large share of the energy consumption in the residential sector by today comes from renewables, especially in the developing world. By 2030 this pattern will have changed, with instead a larger share of electricity and oil in the energy production. In the commercial sub-sector, space heating will also be the largest energy user in 2030, with 36% of energy consumption. The second and third largest segments are lighting with 22% and water heating with 16%. The commercial sub-sector today stands for 3.0 Gt CO₂-emissions. Under BAU, this is expected to rise with 60% to 4.8 Gt in 2030. Low cost abatement possibilities could, however, hold the emissions at 3.1 Gt – an increase by a little more than 3%.