Urban Planning to Beat the Heat

Scientists from Four Countries Study the Impact of Climate Change on Megacities

Mar 18, 2014

Kairo zählt zu den bevölkerungsreichsten Städten weltweit.
Cairo, one of the densest cities in the world. Image Credit: Wikimedia Commons | Luc Legay

Cairo, Istanbul, and Nairobi – each of these three megacities has an official population of up to 16 million, with even more uncounted residents in the swelling settlements on the outskirts of town. Traffic chaos is the norm, and during the summer, the heat in the city is almost unbearable. Climate change will further exacerbate the issues faced by booming urban centers over the next few decades. But how can the microclimate in these areas be improved?

This is the subject of research for scientists from Germany, Egypt, Kenya, and Turkey. After speaking with urban planners and other local stakeholders, the researchers are developing recommendations for how these three megacities could improve quality of life for residents. “The knowledge that local people have from experience is very important,” explains Sahar Sodoudi, a professor of urban climatology at Freie Universität, who is involved in the project together with her colleague Ines Langer on the German side. “They know how much water trees really need, and which species are especially good for providing shade,” she explains.

The team aims to ensure that all of the recommendations are ultimately also feasible. Microclimate model calculations are compared against measurement data collected in the cities to locate the hottest areas and initiate steps to curb the heat there. Possibilities include roofs with built-in cooling, or painting building exteriors white. The scholars are now using climate simulations calculated via supercomputer to study the effects of the planned measures for the future.

Integrating Local Residents’ Knowledge

In this initiative, regional knowledge and state-of-the-art research serve a common goal. It is of particular interest, the meteorologists say, that the three cities being studied are located in different climate zones. Alongside their expertise, the specialized knowledge of urban and landscape planners is also going into these efforts. Complex problems require complex solutions, so the many different perspectives are pooled together in the project that is funded by the EU’s ERAfrica program.

The population of Cairo rose from 20 million in 2006 to 35 million in 2012, which caused a dramatic increase in human-generated heat, Sodoudi reports. But what sustainable urban-planning measures can be taken to mitigate the effects of climate change and of “urban heat islands”? “We recommend that care be taken to include green space between neighborhoods when cities expand,” Sodoudi says. At the same time, these areas could also allow city dwellers to grow their own food, Langer explains, “like in Germany’s community gardens, the so-called Schrebergarten.”