Urban planning can reduce urban GHG emissions in transport and buildings by 14% in 2050

Urban planning is a key lever for municipal climate mitigation, relevant for both reducing greenhouse gas (GHG) emissions in urban transport and within the building sector. However, it is unclear how large the municipal mitigation potential of urban planning is. Here, we develop scenarios that explicitly consider the contribution of new settlements between 2025 and 2050 for both transport - by reducing the distance traveled by cars and by modal shift -, and buildings - by supporting more compact building forms that reduce energy use and construction demand. We find that urban planning - a focus on compact design, mixed use, and low-carbon transport infrastructure - can reduce future GHG emissions by 14% compared to business as usual, with about equal contributions from transport and building sectors, notably including construction. Our analysis highlights the importance of developing and rapidly growing cities in Asia and Africa in supporting urban planning-related mitigation efforts.