Urban planning and climate change are closely interlinked. The way we build our cities affects both the local and the global climate. Dense urban development and paved inner cities not only generate more heat, they are also increasingly creating problems for citiy sewer systems. Rainwater cannot run off easily, so that the groundwater is more difficult to replenish, and the risk of flooding increases. Climate change is increasing this phenomenon, since extreme weather conditions such as heavy rain, droughts or heat waves are occurring more and more frequently.