For the three-quarters of Europe's population that lives in cities and towns, a good urban environment is a precondition for a good quality of life. This quality of life depends inter alia on clean air and water, efficient transport, low noise levels and green spaces.
Despite substantial reductions in some urban air pollutants, data for the period 1997 to 2008 show that for any given year up to 40 to 60 % of urban citizens can be exposed to concentrations of either particulate matter or ozone above the EU limits. Environmental noise, mainly from transport, continues to affect large numbers of people. Urban wastewater collection and treatment improved markedly, but discharges of some harmful chemicals remain a concern.
Cities, due to the high concentration of people and activities, deliver and demand goods and services that impact their own areas and regions far away. While cities in Europe contribute 69 % of the continent's CO2 emissions, an urban resident consumes less energy than a rural resident. Urban density and compactness enable more energy efficient forms of housing and transport – an asset for a more sustainable Europe.
Despite some improvements, European cities and their inhabitants will still face a number of important challenges in the future. They are highly vulnerable to many impacts of climate change such as heat waves, water scarcity, flooding, and related health problems, and will still need to cope with high transport loads, air quality problems, noise and loss of green areas.
Cities can be considered as 'ecosystems', albeit with a high technical component. Their urban metabolism is an open and dynamic system, which consumes, transforms and releases materials and energy, develops and adapts to changes, and interacts with humans and other ecosystems. Therefore they should be analysed and managed as other ecosystems.
The urban environment is under pressure from sources both inside and outside individual urban areas, and local situations are influenced by national and European legislation as well as programmes. Therefore, a broadly integrated approach from the local to the European level and across sectors would be beneficial for a more sustainable urban development across Europe.