Cities and metropolitan regional governments should play a more prominent role in defining the wider response to climate change, according to a report from the OECD.
Cities and climate change confirms that urban areas use most of the world's energy and are responsible for most of the world's greenhouse gas emissions. Cities are at the same time highly vulnerable to rising sea levels, warmer temperatures and destructive storms expected to result from climate change: By 2070, 150 million city-dwellers, producing 9% of global GDP in coastal cities, will be exposed to the full brunt of climate change, the report said.
"Cities are at the center of the problem, and given their role as the predominant consumers of energy, they are also a necessary part of the climate change solution," OECD Secretary-General Angel Gurria said. "Urban policymakers should immediately start reshaping their cities' futures, using better urban planning and policies to reduce energy use, cut greenhouse gas emissions and make their infrastructure more resilient."
The OECD identifies best practices in energy, housing, urban planning, public transport and other policy areas that limit cities' contribution to climate change and help adapt to expected impacts.
Densely-populated cities in South Korea and Japan produce lower CO2 emissions per capita than sprawling urban areas in Australia, Canada or the United States. Similarly, New York's greenhouse gas emissions are far below those seen in Los Angeles, thanks to its compact form and larger reliance on public transport, the report said.
Policy decisions can help cities tackle these disparities. Better land-use policies and eliminating property taxes that favor single-owner housing could decrease urban sprawl. Greater financial support for public transport could convince city dwellers to leave their cars at home. Congestion charges in cities from London to Stockholm to Seoul have shown that taxing drivers can change behavior and reduce pollution.