The mayors of Budapest, Los Angeles. Mexico City and Oslo are the first signatories of a new declaration targeting a 50 per cent reduction in carbon emissions from construction projects by 2030. The pledge is a C40 Cities initiative, which will be seeking support from municipal leaders and the local development industry in other major global cities to raise awareness about embodied carbon levels of buildings and infrastructure.

Mayors Gergely Karácsony, Eric Garcetti, Claudia Sheinbaum and Raymond Johansen  have committed to supporting the repurposing and retrofitting of existing buildings and facilities with an eye to exhausting the full lifecycle of carbon-intensive building components and materials. Notably, concrete production accounts for 8 per cent of annual global greenhouse gas emissions.

“Embodied emissions in construction activities and materials are uncharted areas, where large mitigation potential can certainly be found,” Mayor Karácsony observes. “Budapest wants to find its way to mobilize its ecosystem to make significant improvement in this field.”

The mayors’ pledge is to be accomplished through planning policies, design standards, building codes and procurement and contracting processes that promote zero-emission construction machinery, transparent reporting of embedded carbon in the supply chain and frugal use of raw material. The mayors have also agreed to approve at least one prominent net-zero construction project by 2025, and to produce annual progress reports on their actions.

“We are confident that the C40 Clean Construction Declaration will contribute in shifting the construction market globally,” says Oslo’s Mayor Johansen. “Together, we can remove fossil fuels and reduce emissions from construction sites altogether. This will make them safer, quieter, cleaner places to work, and will ensure that the air in our cities is cleaner and healthier to breathe.”