ASU study: Wealth buys rescue from metro Phoenix’s urban heat island

[Source: Shaun McKinnon, Arizona Republic] — Heat discriminates.  Phoenix’s sweltering summer inflicts the most misery and illness in poor neighborhoods, a new study shows, and among people least able to protect themselves from the elements.  Conditions in those neighborhoods, with their sparse landscaping, high-density housing and converging freeways, create pockets of extreme heat that persist day and night.  Inside, homeowners sometimes can’t afford to turn up — or even turn on — the air-conditioner.

Wealthier homeowners, meanwhile, often in neighborhoods just blocks away, maintain lush yards and trees that help cool the air more quickly at night, shortening the hours of the hottest heat waves.  They can buy further relief with a nudge of the thermostat.

The disparities present threats more serious than just discomfort on a hot day, according to the study, produced by Arizona State University researchers.  Prolonged exposure to heat can cause illness or even death. The densely developed nature of the hottest areas also means more of the people most vulnerable — the elderly, children, the homebound — live in the neighborhoods where the risk is greatest.

That link between money and the ability to cope with extreme weather emerged clearly in the research.  Among the startling revelations: For every $10,000 an area’s income rises, the average outside temperature drops one-half degree Fahrenheit.  “It’s an environmental-justice issue,” said Darren Ruddell, a geographer who led the study.  “The people who are most vulnerable are also living in the worst conditions.  It’s a double whammy.”

The researchers say they hope their findings will spur discussions about better managing land, water and energy use, factors that will grow more critical if temperatures rise in coming years, as climate-change models predict.  “If we can identify the areas most at risk, we can try to help them,” Ruddell said.  “We could redesign neighborhoods, build cities differently, improve warning systems and ultimately reduce our vulnerability to heat.”  [Note: To read the full article, visit ASU study: Wealth buys rescue from metro Phoenix’s urban heat island.  Corresponding PDF graphic here.]