Urban Heat Island Effect is Making Heat Waves Worse in Cities, Study Shows
Sourced from Canada’s National Observer
The sweltering heat endured by major American cities is being fuelled by vast swaths of concrete and a lack of greenery that can ratchet up temperatures by nearly 9 F (5 C) compared with surrounding rural areas, new research has found.
In the past month, Phoenix experienced a string of four days above 115 F (46 C) for the first time and Boston hit 100 F for the first time in a decade. A deadly heat wave in the U.S. northwest, which scientists say would have been “virtually impossible” without human-induced climate change, baked Seattle at a record 108 F, while Portland, where roads buckled and power cables melted in the heat, reached an incredible new high of 116 F.
The intensifying heat is heightened in large urban areas by their design, according to a new report that has attempted to quantify where the “urban heat island” effect is most acute.
By applying an index based on land use, the amount of reflective surface, population density and other factors, researchers have determined that of 158 U.S. cities, New Orleans has the largest heat disparity with its immediate surrounds — an average 8.9 F hotter.
Newark, N.J., has the second largest heat island effect, an average 7.7 F hotter than its surroundings, while New York City is 7.6 F hotter. Houston is fourth on the list, followed by San Francisco.