ETH The population living in cities has been increased both in developed and developing countries.
City areas enable people to have a high quality of life through various urban activities.
On the other hand, the urban area contributes to anthropogenic environmental loading substantially through the emission of greenhouse gas and others. Urban metabolisms such as the flow of energy, water use and wastewater discharge, and solid waste flow must be improved. The direct emission of carbon dioxide is not necessarily large, but the indirect emission is high through the consumption of products that are manufactured while emitting carbon dioxide in large cities where commercial activities rather than industrial activities are abundant. Such indirect environmental loading should be taken into account to judge the sustainability of an urban area. University of Tokyo, MIT and ETH are jointly studying various aspects of the sustainability of cities.