As climate change continues to bake the Earth, it is not merely the presence of greenhouse gases in the atmosphere that is heating our cities. In many cases, human-made infrastructure is exacerbating or even making our cities more uninhabitable.
Indeed, as the world warms, something called the "heat island effect" is a major threat to countless cities. The heat island effect is a phenomenon in which urban areas experience higher temperatures than the areas adjacent to them. It is typically caused by infrastructure, like buildings and roads, absorbing excess heat; they retain that heat that they absorb during the day and keep cities hot, even at night time. This is why the summer overnight low in cities like Phoenix, Ariz., is often 90° Fahrenheit or higher.
