Concrete jungles absorb and hold heat very differently to the natural environment and this will force city planners to consider how life in the city will need to adapt as climate change increases in intensity over time.
The Urban Heat Island (‘UHI’) is the effect that describes the way heat is captured by urban environments. Yale University has developed a Google Earth app that allows you to compare the UHI effect in almost any populated city on Earth. Comparisons are easiest when the climatic conditions are similar – pairing a city in the desert against the tropics may not be directly comparable. We used the tool to compare two English cities, the largest being London with a 9m population and a relatively small city of Exeter with 100,000 residents. London had over double Exeter’s UHI. When interpreting the effect of UHI be aware that even cities with large populations may have quite different UHI’s despite similar climatic characteristics including the use of greenery, the skyline of the buildings and the ‘waste heat’ from air conditioners and car exhausts.
This tool allows researchers to consider to degree clever city planning can reduce the effects of climate change. The University of Edinburgh researched three case studies in Glasgow and Dundee and found that over 34% of city space was dedicated to roads and parking. Conversely in large event locations like stadiums more space was dedicated to smoking areas than bike parking. Improving city design around transport has large gains for the community as it would improve both our emission footprint and the UHI effects of climate change.
UHI and its effects on cities is anticipated to become a growing expense and inconvenience to city dwellers as climate change continues some cities may become difficult to live in without major changes to design. Innovation is being used to develop new building materials that will withstand such punishing environments. ‘Cool’ building materials is one way city planners can reduce the UHI through pavements that reflect more sunlight and are more porous so they absorb water and stay cooler for longer in summer.
New York City’s local government has been coating city rooftops with a white, reflective coating that reduces building energy use, contributing to lower cooling costs and avoiding an estimated 3,315 metric tons of carbon dioxide equivalent (tCO2 e) emissions in the city. Whilst city dwellers are facing a disproportionate impact from climate change, the opportunities to rethink city design to consider the changing environment and reduce the environmental damage traditionally associated with urban settings is possible.