Abstract
Achieving the Paris Agreement's goals of holding global temperature rise well below 2 °C with efforts to limit it to 1.5 °C requires rapid reductions in greenhouse gas emissions. The built environment embodies substantial emissions, posing a challenge to meeting these goals. We quantify the carbon cost of constructing the global built-environment over the past three decades and project it to 2050. Our findings indicate that the global construction carbon footprint has doubled over the past three decades and is projected to more than double by 2050. In 2022, over half of the construction industry's carbon emissions stemmed from cementitious materials, bricks, and metals, while glass, plastics, chemicals, and bio-based materials contributed 6%, and the remaining 37% arose from transport, services, machinery, and on-site activities. Under the business-as-usual scenario, the construction carbon footprint alone will exceed the per-annum carbon budget for the 1.5 °C and 2 °C goals in the next two decades. It will use up all remaining carbon budget for the 1.5 °C goal by 2050, as our analysis highlights. Therefore, we advocate for a material revolution, such as replacing traditional materials with biobased materials, which leverages economies of scale and paves the way for a transformative and sustainable future in construction.