Natural disasters due to weather extremes occur frequently, both in Europe and in the rest of the world. In the first decade of the 21st century, for example, 3000 natural disasters were reported worldwide due to flooding, heatwaves, drought, storms and cyclones. Climate change means that disasters such as these could occur more often.

By 2050, around 70% of the world's population of 9,2 billion people is expected to live in an urban environment. Especially in developing countries this increasing population and expanding cities pose great challenges with respect to access to clean drinking water, sanitation, waste water treatment and protection against floods.