Emissions budgets tool maps construction carbon limits for 1,000 cities

Researchers at the University of Toronto have released an open‑source model and public dashboard that allocates construction‑sector greenhouse‑gas emissions budgets to 1,000 cities worldwide, using climate-model carbon budgets and city-level data; the paper describing the method appears in Nature Cities.

Researchers at the University of Toronto’s Centre for the Sustainable Built Environment have developed an open‑source model that produces construction-related greenhouse gas emissions budgets for 1,000 cities. The team published the method in Nature Cities and built a public dashboard so users can view and compare city budgets. The approach combines an extended environmental input–output model with statistical regression to allocate a global carbon budget to cities at the construction-sector level. Collaborators include researchers at the University of Cambridge and the University of Waterloo. Key facts: - The model provides city-level emissions budgets for the construction sector for 1,000 cities worldwide. - Methodology uses an extended environmental input/output framework plus regression to allocate a global carbon budget derived from climate models. - For demonstration the team used two allocation strategies: equally per capita and a grandfathered approach that reflects historical per-capita building emissions. - A public dashboard accompanies the model so users can view budgets and compare cities. - The researchers report that, for example, Toronto would exhaust its construction budget in 21 years under the grandfathered method and in seven years under equally per capita, and they report required annual reductions of roughly 20–40% to 2050 in that example. Summary: The tool gives cities a way to see construction-sector carbon limits and to compare allocation methods at a local scale. The authors say the open-source method can be adapted to other sectors such as public transit; broader uptake by cities and how they will use these budgets is undetermined at this time.