Cities contribute an estimated 70 percent of the world's energy-related greenhouse gases (GHG). Their locations, often in low-elevation coastal zones, and large populations make them particularly vulnerable to the impacts of climate change. But cities often take steps, even ahead of national governments, to reduce GHG emissions. So it is with China's cities, which are well placed to chart a low-carbon growth path to help reach China's national targets for reducing the energy and carbon intensity of its economy. China's cities will need to act on multiple fronts, in some cases scaling up elements of existing good practice, in others changing established ways of doing business. Actions affecting land-use and spatial development are among the most critical to achieving low-carbon growth as carbon emissions are closely connected to urban form. Spatial development also has very strong 'lock-in' effects: once cities grow and define their urban form, it is almost impossible to retrofit them because the built environment is largely irreversible and very costly to modify. Furthermore, cities need energy-efficient buildings and industries. They need a transport system that offers alternatives to automobiles. They need to shift to efficient management of water, wastewater, and solid waste. And they need to incorporate responses to climate change in their planning, investment decisions, and emergency-preparedness plans.
