Alissa Walker of Gizmodo has a piece up today about the deceptively hot effect tall buildings have on their cities. To prove her point, Walker provides this photo taken from the International Space Station. It shows Manhattan from above, two dark areas immediately drawing the eye’s attention: Midtown and Lower Manhattan. These areas, saturated with skyscrapers, may look cool and shady compared to the rest of the city but science tells us otherwise.
What’s the Big Idea?
As Walker explains, tall buildings create “urban canyons” into which relatively small amounts of light penetrate. That light gets reflected back up and absorbed into the walls of buildings. With the absorption of light comes the retention of heat and these city segments experience upticks in temperature. That heat remains in the building materials throughout the day and into the night, causing temperatures to be consistently higher there than in other parts of the city. Walker quotes climatologist Stuart Gaffin, who finds the trend unsettling:
“I see surface temperatures in the city that routinely exceed what you might find in the desert.”