How to build cooler, healthier and cheaper cities

Around the globe, climate change is starting to have a major impact on city life through rising temperatures, an increase in the risk of floods and droughts and a drop in property values.

To find out how urban planners, landscape architects and water experts can work together to sustainably bring down city temperatures, fight water shortages, protect homes and businesses from damage by flooding – and increase biodiversity and save money in the process – Climate-KIC has launched the Blue Green Dream project.

The Blue Green Dream project highlights the multiple benefits that could be gained, such as air quality, noise dampening, public health and aesthetic improvements by better integrating water (Blue) and vegetated (Green) infrastructures. “We want people to see trees and plants as more than just something pretty to look at, and cities as sources of water not just consumers of water,” said Čedo Maksimović, head of the Blue Green Dream project on behalf of Climate-KIC and Professor of Civil and Environmental Engineering at Imperial College London, where he heads the Urban Water Research Group.


Local temperatures

Maksimović points to the natural cooling effect of trees and other vegetation in particular as a potential revolution in urban planning, which would see smart irrigation channels distribute rainwater to trees in order to stimulate evaporation and reduce flooding. “Most city trees get fed exactly enough water to survive – if that. By changing that we estimate we can bring down local temperatures by as much as three degrees Celsius,” Maksimović said.

No small feat if you take into account that high urban temperatures can claim unnecessary lives. On a hot summer’s day, the temperature in a city like London can be six degrees higher than its rural surroundings, Maksimović pointed out, stressing that up to 50.000 Europeans are estimated to have died in the 2003 heat wave – a situation where every degree counts.

Maksimović said redeveloping urban areas to be cooler, greener and safer could not only save lives and costs, but also increase property values.


Demonstration sites

The Blue Green Dream project combines the strengths of a number of Climate-KIC partners, including Imperial College London, Corporation for London and the Institute of Sustainability in the UK, Delft Technical University, Deltares, Alterra, Bosch Slabbers and Arcadis in the Netherlands, TU Berlin in Germany and École des Ponts ParisTech and Veolia Environnement in France.

Maksimović and his team have set up demonstration and research sites in a number of European cities. “It is important to demonstrate that these technologies work, and to document the impact so we have a clear picture of how much energy – and costs – can be saved,” Maksimović says.

Find out more about the demonstration sites and read the full interview with Čedo Maksimović on the Climate-KIC blog.