Figure 2.5 Projected greenhouse gas emissions from building
materials in a business-as-usual scenario to 2060
Emissions from concrete, steel, brick, aluminium, glass, wood and copper are all set to increase substantially.
Source: Zhong et al. 2021.
Embodied Emissions from Extracting and Producing Building Materials
The share of emissions from producing building materials grew from 15% in 1995 to 23% in 2015.
Despite its massive contribution to climate change, the embodied carbon within materials has been under-addressed in decarbonisation strategies. In 2020, the International Resource Panel (IRP) highlighted the enormous potential to reduce emissions through strategies that increase the efficiency of material use in residential buildings. In the G7 countries as well as China, strategies such as the use of recycled materials could reduce emissions in the material cycle of residential buildings by 80 to 100 per cent by 2050 (IRP 2020). In India, the reductions could reach 50-70 per cent (IRP 2020).
The production phase of building materials is the main contributor to embodied carbon in buildings. With the surging demand for materials, the share of greenhouse gas emissions from producing building materials grew from 15 per cent in 1995 to 23 per cent in 2015 (IRP 2020). Historically, smaller buildings were made with local, lower-carbon materials (such as earth masonry), but these are increasingly being replaced by larger, carbon-intensive concrete and steel structures.
Many of the most commonly used construction materials today rely on energy-intensive, mineral-based extractive processes, and their emissions are set to increase (see Figure 2.5). In addition to climate impacts, these extractive processes can have deleterious social and environmental impacts across the material life cycle, such as biodiversity loss, high water consumption, water contamination and risk of forced labour.
The cement industry accounts for 7% of global CO2 emissions.
●
The production of cement and steel for construction accounts for more than 11 per cent of global and process-related carbon emissions (Global ABC, IEA and UNEP 2019).
●
Embodied emissions from the iron and steel industry comprise around 7 per cent of global greenhouse gas emissions and 11 per cent of global carbon dioxide (CO2) emissions (Hasanbeigi 2021).
●
The cement industry accounts for another 7 per cent of global greenhouse gas emissions, generated during the production and implementation of concrete structures (Hasanbeigi 2021; Miller et al. 2021).
