Climate Change and the Building Sector
Today, it is widely accepted that human activities are contributing to climate change. The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) estimated that between 1970 and 2004, global GHG emissions due to human activities rose by 70 % (Genge et al. 2014; Intergovernmental Panel on Climate Change (IPCC) 2007). While the full implications of climate change are not fully understood, scientific evidence suggests that it is a causal factor in rising sea levels, increased occurrence of severe weather events, food shortages, changing patterns of disease, severe water shortages, and the loss of tropical forests. Most experts agree that over the next few decades, the world will undergo potentially dangerous changes in climate, which will have a significant impact on almost every aspect of our environment, economy, and society.
The building sector contributes up to 30 % of global annual GHG emissions and consumes up to 40 % of all energy. High-rise buildings have a significant part to play in this situation. The GHG emissions from buildings primarily arise from their consumption of fossil-fuel-based energy, both through the direct use of fossil fuels and through the use of electrical energy. Significant GHG emissions are also generated through construction materials, in particular insulation materials, and refrigeration and cooling systems (Genge et al. 2014; IPCC 2007). By far, the greatest proportion of energy is used during a building’s operational phase. Though figures vary from building to building, studies suggest that over 80 % of GHG emissions take place during this phase to meet various energy needs such as heating, ventilation, and air-conditioning (HVAC), water heating, lighting, entertainment, and telecommunications (Seppo 2004; Suzuki and Oka 1998; Adalberth et al. 2001). A smaller percentage, generally 10-20 % of energy is consumed in materials manufacturing and transport, construction, maintenance, and demolition. Governments can therefore achieve the greatest reductions in GHG emissions by targeting the operational phase of buildings.
High-rise buildings also have a major role in the operational phase. The building sector has the largest potential for significantly reducing GHG emissions compared to other major emitting sectors. This potential is relatively independent of the cost per tonne of CO2 Eqt., (Genge et al. 2014; IPCC 2007). The IPCC’s Fourth Assessment Report illustrates that the potential for GHG reductions from buildings is common to both developed and developing countries, as well as countries with transiting economies (Fig. 9.16). This means that with proven and commercially available technologies, the energy consumption in both new and existing buildings can be cut by an estimated 30-80 % with potential net profit during the building life span (Genge et al. 2014; IPCC 2007).
Fig. 9.16 Estimated economic mitigation potential by sector and region using technologies and practices expected to be available in 2030. The potentials do not include non-technical options such as lifestyle changes. Source: IPCC (2007)