Understanding the Inequality of the Urban Heat Island Effect

a river in the city

9 February 2022 – by Mia Bezar

This article is part of Earth Refuge’s Spotlight Series on Philadelphia

During the summer of 2021, cities across the United States (‘US’) have seen record breaking temperatures to an extent that scientists say would have been “virtually impossible” to reach without anthropogenic climate change. Cities are especially prone to such extreme heat because of particular characteristics which cause people within urban areas— particularly low-income residents — to bear an undue burden of the effects of climate change. 

What is the Urban Heat Island Effect?

Heat islands are urban areas that experience higher temperatures than their surrounding areas for a variety of reasons. For one, cities contain more man-made structures, such as buildings, roads, and dark roofs, which absorb and re-emit the sun’s heat more than natural land does. Additionally, more vehicles, more air conditioning units, and more industrial facilities all contribute to the heat island effect felt in cities across the world.

The city of Philadelphia is a paradigmatic heat island. Since 1970, Philadelphia’s average summer temperature has increased by three degrees Fahrenheit (-16 °C), leading to more extreme heat events. In the past fourteen years alone, heat-related events have caused nearly 150 deaths in Philadelphia. The magnitude of such tragedy is only expected to grow larger. Just this past summer, Philadelphia declared a Heat Health Emergency, which only occurs from May through June when temperatures are expected to reach 101°F (38 °C) or higher for two consecutive days, or 98°F (37 °C ) or higher for three or more consecutive days. This designation puts services like the city’s heatline into effect and bars any residential utility shutoffs.

The Disproportionate Impacts

Philadelphia is a quintessential heat island not only because the city has become hotter overall, but also because within the city — as in so many others — low-income neighborhoods and communities of color face disproportionate impacts of the increasing temperatures. 

Philadelphia’s Hunting Park neighborhood, one of the city’s most impoverished areas, is illustrative. A recent report from the Philadelphia City Planning Commission showed that more than 75% of land cover in Hunting Park was comprised of buildings, roads, and paved surfaces. By contrast, tree canopy — which helps reduce heat — covers only 9% of the neighborhood. As a result, the neighborhood tends to be significantly warmer than the average city temperature: average surface temperature data shows that Hunting Park can be as much as 22°F (-6 °C) warmer than other neighborhoods. 

These differences in landscape between Hunting Park and the rest of the city are largely a consequence of redlining, the systematic denial of financial services to residents of particular areas usually based on race. Redlining largely influenced historic housing policies in the US that led to the residential segregation that still exists today. Research shows that surface temperatures in formerly redlined neighborhoods in urban areas across the country tend to be up to 36°F (2 °C) warmer than non-redlined areas. While these trends are most pronounced in Southeast and Western cities in the US, the Philadelphia Heat Vulnerability Index shows that they remain consistent in Philadelphia as well.

Effective Solutions

Fortunately, action can still be taken at a more regional level to combat the effects of the urban heat island. Two of the most straightforward solutions are to increase the number of white roofs and to increase tree cover. Data from the Center for Clean Air Policy shows that white or light-colored roofs can reflect up to 80% of the sun’s rays in comparison to the 70% heat absorption of black roofs, in turn allowing homes to stay at lower temperatures. 

Adding more tree canopy would also go a long way. Trees tend to absorb anywhere from 70 to 90% of sunlight in summer, and 20 to 90% of sunlight in winter, leading to significantly reduced temperatures in Hunting Park and other neighborhoods that are rapidly warming. 

Although both solutions would require substantial investment, the benefits outweigh the costs. Indeed, data shows that more trees provide stormwater benefits and increase property values. More importantly, investment in reducing the impacts of the urban heat island effect and climate change more generally represents a small piece of a large effort owed to underserved communities. As climate migration continues to drive people to seek refuge in cities, it is becoming increasingly important to ensure that cities are prepared to provide these types of resources to current and future residents.

Cleaning Up a Toxic Legacy: The Fight Against Environmental Racism in Philadelphia

drone shot of philadelphia city

9 February 2022 – by Mia Bezar 

This article is part of Earth Refuge’s Spotlight Series on Philadelphia

In the middle of the night on June 21, 2019, residents across the city of Philadelphia were awoken by an explosion at the Philadelphia Energy Solutions (‘PES’) Refinery. Only days later, as the damage was still being assessed, PES announced that it would permanently close the refinery, marking the end of a major piece of an industry that has been present in Philadelphia since the Civil War. 

Although residents were pleased by its closure, the refinery’s lingering effects continue to put Philadelphians at risk every day, underscoring the 150 years of suffering and now irreversible damage that the PES refinery has done to surrounding neighborhoods. Nevertheless, these neighborhoods have mounted a strong response to raise awareness and push back against the refinery, ultimately influencing the space’s future.

Background

The petroleum industry grew quickly in Philadelphia. By 1822, just years after the discovery of petroleum in Titusville, Pennsylvania, the refinery that would later become PES was one of America’s largest. In fact, by 1891, Philadelphia produced 35% of all US petroleum exports. And by 2012, the refinery had become one of the largest on the east coast. 

Given the refinery’s scale, it is perhaps unsurprising that it has harmed—and continues to harm—the surrounding communities. Before the explosion, the refinery was responsible for 72% of toxic air emissions in Philadelphia. As a result, Grays Ferry, the predominantly African American neighborhood immediately bordering the refinery, continues to bear the brunt of the refinery’s effects. Residents there experience alarming rates of asthma, cancer, and other life-threatening health conditions when compared to their neighbors across Philadelphia. 

A History of Environmental Injustice

The harm did not stop after the explosion and subsequent closure of the refinery. An investigation by the US Chemical Safety and Hazard Investigation Board found that the PES explosion released 5,239 pounds of hydrofluoric acid – a deadly chemical – into the air. Even three years after its closure, the refinery continued to emit extremely high levels of benzene, a cancer-causing chemical. 

This story of environmental racism is not unique to Grays Ferry or Philadelphia. Indeed, one study from the American Public Health Association found that African Americans were more than 1.5 times more likely to be exposed to particulate matter emissions because of their proximity to pollution-emitting facilities. Another study reported that African Americans are 75% more likely to live near facilities releasing hazardous chemicals into the air.

Pushing Back 

Despite the pervasive effects of the now-defunct refinery, the surrounding neighborhoods continue to push back. In 2015, a group of Philadelphia residents founded Philly Thrive, an environmental justice group that runs strategic campaigns focusing on fossil fuel divestment, energy insecurity and injustice, and environmental racism. While discussions of climate migration often revolve around where to go, it is important to acknowledge that many people do not have the resources to move. Thus, the alternative is to work towards improving conditions at home, which is what Philly Thrive aims to do. 

While Philly Thrive’s original “Right to Breathe” campaign was unsuccessful in stopping Philadelphia from developing a gas plant in 2019, the group has prevailed in its four other campaigns, including its “Contesting for Closure” campaign, which helped push for permanent closure of the refinery. Its current “Right to Thrive” campaign revolves around the future of the refinery and uprooting the environmental racism embodied by the history of the refinery. Beyond pushing legislative action, Philly Thrive provides meeting spaces to address concerns within the organization and to amplify voices and provide safe spaces for members of the community. 

As for the refinery, there may be brighter days ahead. In January 2020, a Chicago-based real estate development company acquired the PES Refinery for $240 million and has plans to convert the 1,300 acres into a green and sustainable commercial hub. 

Closure of the refinery represents an important step forward for the city, and particularly for impacted communities. While there is still a long way to go to even begin to reduce the refinery’s effects, the space appears to have a greener future ahead.

However, it is important to note that just because the space has a greener future does not mean that all its resulting problems will be solved: there are still concerns around transparency and equity, especially with respect to those that have been most affected by the refinery. 

How Green is Philadelphia?

body of water near city buildings during daytime

9 February 2022 – by Mia Bezar

This article is part of Earth Refuge’s Spotlight Series on Philadelphia

When Michael Nutter stepped onto the stage at a forum for the 2007 Philadelphia mayoral primary election, he appeared to be in last place, trailing behind far more prominent and powerful candidates. The one advantage that Nutter had, however, was that he was the only candidate prepared to discuss environmental policy. Shortly thereafter, Nutter mounted a comeback and was elected mayor, making sustainability and environmentalism central to his administration’s work, declaring a goal of making Philadelphia the greenest city in America.

Even though good has come of that initial 2007 commitment to sustainability, there are still several environmental challenges to be addressed before Philadelphia can truly live up to the label of being the “greenest city in America.”

Greenworks

In 2009, during the Nutter administration, the city launched Greenworks, an innovative initiative that set a long-term vision for sustainability goals in Philadelphia and paved the way for several key programs. Greenworks was unique because it not only spurred environmental policies, it also aimed to weave sustainability into all areas of city policy. In many ways, Greenworks has found major success and served as a model for other cities across the country.

One major Greenworks success has been a cross-departmental program targeted toward reducing the city’s asthma rates. Through a collaboration between Philadelphia’s Departments of Sustainability and Public Health, the city has improved indoor air qualities in areas with higher rates of asthma by encouraging smoke-free policies and reducing other asthma triggers. As a result, rates of asthma hospitalizations in children have declined significantly since the program was launched.

Greenworks has also created programs to address larger environmental drivers of health issues like asthma. In 2019, the city passed the Building Energy Performance Policy, which requires large non-residential buildings to either certify high performance or perform maintenance to improve their energy efficiency. With buildings producing around 79% of Philadelphia’s overall carbon emissions, the policy was expected to cut the city’s carbon emissions by almost 200,000 metric tons, or the equivalent of taking 40,000 cars off the road. The policy is just one aspect of the city’s Municipal Energy Master Plan,, the city’s larger plan for reducing carbon emissions. Thus far, the plan has been a success: a recent report shows that Philadelphia has reduced greenhouse gas emissions by 33% since 2006, putting the city on track to reach its goal of reducing emissions by 50% by 2030.

Community Engagement

While Greenworks has fostered successful systems-level initiatives, the Office of Sustainability has also recognized the need for more projects that engage individuals directly. For instance, a Greenworks program called TreePhilly has encouraged thousands of Philadelphians to help work towards the city’s goal of reaching 30% tree canopy in every neighborhood. A related program called the Philly Tree Program partners with non-profit organizations to overcome language barriers to seek input from non-native English speakers in deciding where trees should be planted to maximize their community impact. 

Another realm in which the city has been able to engage the community is with green stormwater infrastructure. In 2011, the Philadelphia Water Department launched Green City Clean Waters, a plan to reduce the amount of stormwater entering sewers. Like TreePhilly, the plan generated overwhelming public support because of surveys and educational resources that the Water Department used to gauge Philadelphians’ interest. Overall, Green City Clean Waters has been a success: in a decade, the city has managed to install enough green tools to keep almost 3 billion gallons of polluted water out of surrounding rivers. However, a report from the city showed that rising sea levels will compromise many stormwater outfall structures, preventing proper drainage. Philadelphia needs to continue to assess its own systems and monitor the situation in order for true climate change preparedness.

Moving Forward

Philadelphia has made significant progress in sustainability, and the city must continue to address the current needs of its residents while preparing for the future. In recent years, the city has managed to educate its citizens on many environmental issues through Greenworks that they would not have been engaged with otherwise. While Philadelphia still has work to do, the city has taken impressive steps in the right direction.