Study: Wealthier valley residents have more shade

By: Devin Browne on 12/27/2011

Phoenix is a great place to study climate change, scientists say -- because it's hot here in a way that they predict other American cities soon will be. Arizona State University researchers have released a study that says we're not all going to be hit with the effects of urban heating equally. From Phoenix, Devin Browne reports.

Shade in high socioeconimic neighborhood

A home in Equestrian Estates, Ahwatukee, Phoenix. ASU researchers found that the availability of foilage and vegetation -- and the cooling effests they provide -- now tracks with income. In 1970, there was no relationship. (Photo courtesy of Chris Martin)

Shade in low socioeconimic neighborhood

A home in south Phoenix. ASU researchers found that the availability of foilage and vegetation -- and the cooling effests they provide -- now tracks with income. In 1970, there was no relationship. (Photo courtesy of Chris Martin)

DEVIN BROWNE: Urban ecologist Chris Martin and team crunched 30 years worth of census data and satellite imagery -- and found that wealthier people in Phoenix don't just have more money. They also have more trees. This is new. In 1970, there was no relationship between tree-accessibility and income. Martin's response to this finding?

CHRIS MARTIN: Shocked. Yes, obviously I was shocked.

DEVIN BROWNE: Martin says this is about more than just aesthetics. Vegetation -- and the cooling effects it provides -- helps mitigate against heat-related costs like air conditioning bills and heat-related illnesses, like heat stroke.

CHRIS MARTIN: People in these higher economic neighborhoods have to begin to realize that it’s to their advantage to see that these lower socio-economic neighborhoods are vegetated. Because collectively as a society, we’re paying for these issues, the health-related problems that are caused by this are borne by the entire population.

DEVIN BROWNE: The City of Phoenix seems to agree. It has set an ambitious goal of covering at least 25 percent of the city in a canopy of trees by 2030 -- ideally with heat-tolerant, low water-use vegetation. Currently, only 12 percent of Phoenix is shaded.

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