Cities are growing engines of economic growth and social change. About 85% of global GDP in 2015 was generated in cities. By 2050, two-thirds of the global population will live in urban areas. Compact, connected and efficient cities can generate stronger growth and job creation, alleviate poverty and reduce investment costs, as well as improve quality of life through lower air pollution and traffic congestion. Better, more resilient models of urban development are particularly critical for rapidly urbanizing cities in the developing world.

International city networks, such as the C40 Cities Climate Leadership Group, Local Governments for Sustainability (ICLEI) and United Cities and Local Governments (UCLG), are scaling up the sharing of best practices and developing initiatives to facilitate new flows of finance, enabling more ambitious action on climate change. Altogether, low-carbon urban actions available today could generate a stream of savings in the period to 2050 with a current value of US$16.6 trillion.

The Global Commission on the Economy and Climate recommends that cities commit to developing and implementing low-carbon urban development strategies by 2020, using where possible the framework of the Compact of Mayors, prioritising policies and investments in public, non-motorised and low-emission transport, building efficiency, renewable energy and efficient waste management. The actions suggested could reduce annual greenhouse gas (GHG) emissions by 3.7 Gt CO2e by 2030.