Life-cycle global warming potential: Key indicator for sustainable buildings

Buildings and the construction industry are responsible for 37% of global greenhouse gas emissions, with possible increase of 50% by 2050 if no actions are taken. Such an increase would intensify global warming, already predicted to reach 1.5 degrees Celsius by 2050. The temperature rise of 2 degrees Celsius would result in even more extreme consequences of climate change than living beings are already experiencing. Until recently, efforts to reduce negative impact of buildings were mainly focused on operational carbon, emissions generated in use phase of the building. Measures to reduce these emissions are well established and include integration of renewable energy sources, improved insulation, installation of energy-efficient appliances and many other well-known energy efficiency measures. However, as the awareness of a building’s overall environmental impact has grown, the focus has increasingly shifted toward assessing the entire life cycle of a building. Embodied carbon, the concept that has recently gained attention, refers to emissions released during other building phases including material extraction, manufacturing, transport, construction and disposal. This approach provides a more comprehensive assessment of a building’s environmental impact. Both embodied and operational carbon are quantified using Global Warming Potential (GWP) expressed in carbon dioxide equivalent (CO2e) used to evaluate the total climate impact of a building over its lifespan. The life-cycle GWP indicator quantifies the contribution of all stages of a building to global temperature rise. This paper presents this indicator, focusing on both operational and embodied carbon, its regulatory framework and future methodological implementation. It explores the challenges in applying Life-cycle assessment in construction sector and examines potential future approaches for establishing a standardized methodology for calculating overall carbon impact of buildings.