Penn State University: NASA-funded research seeks to address vulnerability to extreme heat in cities
A new NASA-funded project will support the development of an internet-based design and planning-decision support platform that will help equitably address urban heat management at the building, neighborhood and city scales.
Travis Flohr, assistant professor of landscape architecture in the Penn State College of Arts and Architecture’s Stuckeman School, is a co-principal investigator on the two-year, $250,000 project that seeks to establish processes that incorporate the science of urban heat – its causes, solutions and impacts on vulnerable communities – into community planning solutions and policymaking.
Flohr’s role in the research focuses on devising scenario planning tools to develop tree planting programs as part of heat mitigation strategies. He’ll be looking at what it takes to get trees to grow, survive and thrive in urban areas and how the street environment, or streetscape, should be constructed to mitigate heat.
“What we are trying to do is to move from analysis-ready data to decision-ready data. That way it’s ready for people to make decisions about the best steps to take to mitigate heat without needing the expertise or the skills to produce the analysis and then interpret it themselves,” said Flohr.
The hope for the research team is to develop a data-driven tool that urban developers can use to make decisions about where to invest and where to guide resources to strategically reduce and offset the effects of urban heat islands, where temperatures are much higher than outlying areas. The tool would also be used by planners writing policy, zoning codes or building code requirements so they could apply the strategies in broader, systemic ways.
“Our hope is that we can move from unit scale to the building scale to the parcel scale and so landowners, building owners and renters that come into an area prone to heat island effect would have access to be able to see what they could do themselves to cool things down, such as put a cool roof in or plant trees or install a green wall. They would know what the best bang for their buck would be in terms of investing in their space,” added Flohr.
Flohr, who has done extensive research into how trees help cool the urban landscape, joins urban climatologists, policymakers, social scientists and community advocacy groups that are looking at the neighboring cities of New York and Jersey City, New Jersey, where policies have been implemented to mitigate extreme heat and can be tracked over time.
Warming temperatures due to climate change are projected to increase the frequency, intensity and length of heatwaves globally and in the United States. Vulnerability to this extreme heat is disproportionately elevated among the elderly, people with preexisting conditions (such as diabetes and heart disease) and those with limited resources to cope with days-long heatwaves. Moreover, studies have shown that low-income and minority communities across the United States are more frequently exposed to high temperatures and have reported more heat-related deaths.
“More often than not, it is the affluent areas in cities that have adequate space for trees and those trees tend to be older, bigger and provide more shade and evapotranspiration in these extreme urban heat scenarios to help cool the environment,” said Flohr. “Affluent communities often have a lot fewer concerns with urban heat island because they have much cooler neighborhoods.”
Meanwhile, low-income areas in cities tend to be more densely populated and have more urban, heat-absorbing materials such as parking lots, buildings and sidewalks, which means there often isn’t room for trees that provide the necessary shade to keep temperatures cooler.
“Recent surveys have shown that it’s almost always hotter in areas where many people of color live not only because these areas are densely populated and lack room to grow trees but because they are dealing with ongoing and legacies of disinvestment by programs such as redlining,” said Flohr.
The term “redlining” refers to the practice that was adopted by the Federal Housing Administration (FHA) following the Great Depression to outline areas with sizable populations of people of color in red ink on maps as a warning to mortgage lenders not to approve loans to those residents. Meanwhile, the FHA was subsidizing builders who were mass producing subdivisions for white, affluent people with the requirement that none of those home be sold to people of color.
“Frequently, the hottest places in cities are historically redlined communities; as a result, people in these communities are still exposed to higher urban temperatures and experience greater health risks from extreme heat events. Additionally, they often can’t afford the means to cool their homes during these events, meaning city governments need to step in and ensure they are mitigating past and present urban heat island issues because it is a matter of public health and environmental injustices,” said Flohr.