Editorial: ICUC-7 Urban Climate Special Issue

The world's population lives in an increasingly urbanized world. The current generation is the first where more people live in cities than in rural areas (United Nations, 2010). Much of the urban growth is taking place in Asia where the urban transition now underway involves a volume of population much larger than in any other region in the world and is taking place on a scale unprecedented in human history. Demographic projections show that by 2025, 16 of the world's 29 megacities (cities with more than 10 million people) will be located in Asia, many of which have very basic problems in terms of environmental quality (Asian Development Bank, 2008). Cities have a direct impact on the local climate and also impact and are affected by climate change in many ways and at many scales.