Got overheated urban areas? Plant trees | The Homepage

By Betul Tuncer

If you walked the streets of Pittsburgh in early October, you may have sweated a bit. While climate change has raised temperatures everywhere, community leaders and climate scientists are highlighting factors that make urban pockets of Pittsburgh hotter, even into early fall.

Urban areas with lots of people, industrial infrastructure, buildings and concrete but minimal green spaces and tree canopy can experience what scientists call the “urban heat island effect.” It makes some areas hotter than others, and when combined with other socio-economic issues can harm residents’ quality of life.

In Greater Hazelwood, the lack of tree canopy resulting from the neighborhood’s industrial history and the historical redlining of the neighborhood make its residents especially vulnerable to extreme temperatures.

Tiffany Taulton, director of outreach and sustainability at Hazelwood Initiative, said heat islands can exist in any neighborhood, but their effects vary depending on the economic conditions of residents.

“Most often, you see heat islands happening in poor areas, because in poorer areas that’s where you have more buildings and you have fewer trees,” Ms. Taulton said.

The U.S. Environmental Protection Agency has reported that historically redlined neighborhoods – where banks refused to insure or issue home loans in the early-to-mid 20th century – are hotter and have more poverty. The census tract map of Hazelwood, which was a redlined area, has 29% tree canopy, compared to the city average of 42%. Glen Hazel, also historically redlined, has 57% tree canopy because it includes the Hazelwood Greenway. But there is still a significant lack of tree cover in residential areas.

Hazelwood has 29.4% of households in poverty, compared with 11.4% average in Allegheny County, according to the U.S. Census Bureau. The average household income is just under $42,000 compared with the county average of $72,000.

Historically redlined areas have markedly lower tree canopy than the city average of 42%. Hazelwood (outlined in orange) has 29% and Greenfield (top) has 23%. Glen Hazel (outlined in black) has 57% because of the greenway, but its residential areas have low tree canopy. Source: Google Environmental Insights Explorer

Maren Cooke, a planetary scientist and environmental educator and activist, said it’s unclear whether Hazelwood is officially designated as a heat island but its residents face higher risks from the effects of high temperatures and climate change.

“The fact that urban heat islands are concentrated in low-income areas, which are often, if not usually, redlined areas makes it a huge climate justice problem,” Ms. Cooke said. “The people who are probably contributing the least to the problem are suffering the most and that goes across this country and across the world.”

Ms. Cooke said high temperatures are one of the biggest causes of death directly linked to climate change. People in low-income areas are at higher risk because they have less greenery and may not be able to afford air conditioning.

“You can’t live above a certain temperature,” Ms. Cooke said.

Asthma, chronic obstructive pulmonary disease and other respiratory illnesses become much worse for people living in urban heat islands, according to Ms. Cooke. High temperatures plus chemical changes that happen when sunlight hits air pollutants can worsen air quality and result in smog, which parts of Pittsburgh saw this past summer.

Beyond the physical illnesses, Ms. Cooke said intellectual and psychological impacts can also affect people’s well-being.

Despite improving air quality and receiving its first passing mark from the American Lung Association, Pittsburgh is still among the worst metropolitan areas for short-term and long-term air pollution.

To help improve air quality and reduce heat island effects, the City of Pittsburgh is partnering with the Resilient Cities Catalyst project to work on data-driven initiatives to address disparities in tree canopy coverage in 20 neighborhoods. Funded through the ICLEI USA Action Fund, the project will work with Hazelwood Initiative, Tree Pittsburgh, the UrbanKind Institute and other community organizations to plant more trees in the Hazelwood area.

Ms. Taulton said the groups have already planted hundreds of trees but this project will focus on areas that have no canopy at all and specifically engage the community through tree plantings planned for Nov. 11 and in the spring. See ad on Page 3.

“The purpose of this grant is to use trees to show how you can economically make a difference in a community,” Ms. Taulton said. “When I say economically, I mean that it is cheaper to plant some trees and make a beautiful sidewalk and make a beautiful neighborhood with tree cover than it is to try to give everyone an air conditioning unit, which does nothing for our planet and creates more waste.”

Quaadir Bey, who works on community and neighborhood engagement for the UrbanKind Institute, said simply planting more trees will not solve the problem of urban heat islands. Local governments and organizations must maintain the trees so they can genuinely benefit neighborhoods. While trees may shade a home, they do not eliminate the cost of cooling it.

Mr. Bey said some people worry that more trees in neighborhoods like Hazelwood might lead to gentrification. More trees can equal higher property values, which can cause residents who already face economic hardships to be displaced.

Mr. Bey said the broader systemic issue in urban heat islands is that they already receive fewer resources than other neighborhoods.

Danielle Dedeaux, an undergraduate student with a focus on climatology at Penn State University, presented on urban heat island impacts on physical and mental health at a community event with the UrbanKind Institute in July.

Along with increasing the resources directed into these communities, Ms. Dedeaux said projects aimed at improving neighborhoods must involve community members.

“If you can’t get the community to be involved with the process, or to be informed about the process and what you're doing and how you’re trying to help, then in a sense you're already failing them,” she said. “They have to talk to the residents and they have to make sure that the residents feel heard and are listened to before anything can happen.”

Betul Tuncer is a University of Pittsburgh student and a Pittsburgh Media Partnership fall editorial intern.