photo: Matt Lemmon via flickr
It may not offer relief from the sweat dripping down your forehead in the midst of a heatwave as you walk down the street, but you can take comfort that it's not all in your head. Heatwaves are indeed getting more pronounced. As Our Amazing Planet reports, sprawling cities have seen the number of very hot days more than double compared to dense, compact ones.That's the conclusion of researchers from Georgia Tech, who examined temperature records from 1956 to 2005 of 53 metropolitan regions in the US. They found that in sprawling cities (think Atlanta) the annual number of very hot days has increased an average of 14.8 days, while in compact cities (think Boston, New York, Baltimore) they have only increased 5.6 days on average.
The researchers have chalked up the increase in hot day frequency to the rate of deforestation in the sprawling urban environment. From 1992-2001 they found sprawling areas had double the rate of vegetation clearance as did more densely developed areas.
Which makes sense--the greater rate of vegetation clearance recently--as most of the densely developed cities in the US are older places, built initially before the automobile and cheap energy made sprawling urban development possible.
The Vicious Sprawl-Energy-Air Conditioning Loop
A roundabout connect the dots: Sprawling urban areas mean more trees cleared --» with larger housing spaces, increasingly cooled by air conditioning powered by greenhouse gas spewing sources --» means increasing average temperatures --» means more air conditioning usage --» [repeat]. Time to rethink this norm from both an energy and architectural/urban planning perspective.
Lloyd offers some good solutions to our deluded world of air conditioning. As does Jennifer in pointing out one of the many ways people built homes in pre-air conditioned times for thousands of years.
More on Urban Planning:
Naturally Temperature-Conditioned Traditional Courtyard Homes: Ready for a Renaissance?
New Research Shows a Baltimore Heat Wave Was Worsened by DC's Hot Air
The Deluded World of Air Conditioning Revisited