Reaching net-zero carbon emissions in construction supply chains – Analysis of a Swedish road construction project

Recent estimates suggest that the construction sector accounts for approximately one quarter of global CO2 emissions. This paper assesses the potential for reducing the climate impact of road construction. The study is structured as a participatory integrated assessment with involvement from key stakeholders in the supply chain, supported by energy and material flow mapping, an extensive literature review and a scenario analysis. The results indicate that it is technically possible to halve road construction CO2 emissions with today's best available technologies and practices, to abate more than three quarters of the emissions by 2030 and achieve close to net zero emissions by 2045. Realising the current potential would rely on sufficient availability of sustainably produced second-generation biofuels, indicating a need to speed up the implementation of alternative abatement measures, including optimization of material use and mass handling requirements, increased recycling of steel, asphalt and aggregates and enhanced use of alternative binders in concrete. Policy measures and procurement strategies should be aligned to support these measures with a clear supply chain focus. For deep decarbonization several key opportunities and obstacles for realisation of breakthrough technologies for basic industry are highlighted – including electrification and carbon capture for steel and cement, and hybridisation and electrification for heavy transport and construction equipment. There is a clear need to prepare for deeper abatement and associated transformative shifts already now and to carefully consider the pathway of getting there while avoiding pitfalls along the way, such as overreliance on biofuels or cost optimizations which cannot be scaled up to the levels required.