Can Urban Physics Cool Hot Cities?

Textures differences between urban areas and rural areas are drastically apparent. All one needs to do is take a look for themselves on Google Earth. When looking at the City of Chicago, for instance, one can see the saturation of large and small structures, constant roads leading in every direction, and scattered green space among the overwhelmingly gray overview. Continue your exploration of other non-urban areas and the patterns of rural landscape make their own textures.

Researchers at the Massachusetts Institute of Technology (MIT) Concrete Sustainability Hub looked at the different textures of these urban areas as well. They discovered that the patterns and properties of a city, as well as the topography of surrounding areas, began to mimic the same patterns as other traditional structures studied under a microscope. What they learned was that the structures of these cities could be comparable to a molecular structure, a new realm designated as 'urban physics.' For instance, researchers found that the arrangement of buildings in New York City could be equivalent to that of a crystal structure. By analyzing the texture of a cities layout, scientists at MIT predict that it can better analyze the effect of urban heat island (UHI). UHI is the effect of exposed urban surfaces heating up their environment 3 to 8 degrees warmer than the current air temperature.

While cities may only cover 2% of the world's land, they contribute to more than 70% of greenhouse gas emissions. Due to the size of these cities and the amount of greenhouse gas emissions, they also strengthen surface temperatures when compared to their rural neighbors. Urban population growth is on the rise and trending to continue to growth for the foreseeable future. According to the World Health Organization, urban populations around the world are "expected to grow approximately 1.84% per year between 2015 and 2020."

We've seen a multitude of different urban areas utilize resources in an effort to combat rising temperatures. Skyscrapers and other high-rise buildings have utilized vegetation in order to offset the UHI effect. However, the research from MIT indicates that taking on the overall infrastructure, to looking at the type of materials that are included in building up cities could be crucial to combating those rising temperatures.

The data could be crucial for city planners across the country. By understanding their own urban physics, they could better utilize other building resources to further minimize energy use and plan for catastrophic weather events. The Portland Cement Association suggests one solution to shifting to cooler temperatures could be building with materials that would not enhance heat conditions. One example could be the use of concrete pavement use throughout infrastructure in a city because it reflects more solar energy than dark pavement surfaces. In addition, other hot pavements and rooftop surfaces transfer their excess heat to stormwater, which raises water temperatures as it is released into streams, rivers, ponds, and lakes. Ultimately, rapid temperature changes can be stressful to aquatic ecosystems. Light colored pavements could ultimately be crucial in reducing the initial warming of stormwater runoff.

As the research continues into the texture that comprises these cities, MIT notes that the multi-disciplinary approach can help cities shift towards using quantitative predictions based on urban physics.