Climate change and China’s mega urban regions

China’s mega urban regions are focal points of economic development and environmental concerns.This paper positions four mega urban regions(i.e.,the Yangtze River Delta,the Pearl River Delta,the Bohai Bay Area,and the South-eastern Fujian Province)along China’s coast into the national economy and elaborates their development challenges and planning innovations.Mega urban regions in China are spatial consequences of rapid economic transition.They deserve close scrutiny and demands for innovative planning responses in order to maintain their key role in driving economic growth but limiting their greenhouse gas emission.