COVID-19 and Urban Heat: A Just Response to Entangled Public Health Risks
By Zef Egan, Christopher Kennedy, Timon McPhearson and Luis Ortiz
This summer, while cities prepare for rising temperatures, heat waves, and a second wave of coronavirus, researchers at the Urban System Lab are thinking about the interrelated risks and just responses to extreme heat and COVID-19.
The National Weather Service declares a heat wave when three consecutive days rise above 90°F. Cities are already experiencing more severe and prolonged heat waves due to the urban heat island effect. Permeable surfaces such as soils, marshes, streams, and leafy canopies (which shade the understory, and cool nights through transpiration) are replaced by asphalt, concrete, brick and other materials which absorb heat during the day and exude heat at night. This transformation of the urban landscape contributes greatly to the urban heat island effect. According to the EPA this means that people living in cities experience days between 1.8–5.4°F warmer and nights that can be a staggering 22°F hotter. Global warming exacerbates this problem. By 2050, New Yorkers could grapple with 7 heat waves a year (up from on average 2 a year now).
Recently, the Cary Institute for Ecosystem Studies hosted a Zoom round table with activists and researchers, including Timon McPhearson, the Director of the Urban Systems Lab, to answer the question: “What are just and equitable solutions to address threats posed by extreme heat and other interdependent risks?” According to McPhearson: “Our question [at the Urban Systems Lab] was: Is the way in which we designed our cities to trap heat, and the way in which we’ve built in structural racism into the way we’ve planned, governed, and built our cities, so that low income and communities of color are facing the brunt of those heat impacts, are those drivers also driving exposure to COVID-19?” While that question cannot be fully answered, the Lab is analyzing interrelated risks involving heat and COVID-19 vulnerability.
Neighborhoods like Hunts Point in the Bronx score highest on the heat vulnerability index. Designated as essential during the Covid-19 pandemic, Hunts Point continues to be a food and waste hub for much of the city. However, exposure to air pollution from multiple sources including the vast network of food trucks and food distribution infrastructure comprises the health of people who live and work there, predominantly communities of color, and renders the impacts of extreme heat and COVID-19 more severe. As Jennifer Santos Ramirez writes in her piece There Was Never A New York “Pause” For The South Bronx: “With one of the highest rates of hospitalization due to childhood asthma in the United States the South Bronx remains a microcosm for how our society treats communities of color, ignoring all of the environmental conditions in which a respiratory virus like Covid-19 would thrive, and setting up the current scenario we are in — where the rate of positive cases by population in the South Bronx far exceeds all other boroughs, and even as the number of cases in NY goes down, those positive for Covid-19 in the South Bronx are twice as likely to die from it.” Researchers at the Technical University of Denmark caution that the comorbidities that contribute to more severe COVID-19 cases (hypertension, cardiovascular diseases, diabetes mellitus, chronic obstructive pulmonary disease, malignancy, and chronic kidney disease) also are risk factors during heat waves.
Hotter nights plague people without air conditioning and those in apartments without cross ventilation most. Researchers from Columbia University found that low household income and neighborhood median income correlated to hotter indoor temperatures during the summer. Air pollution from traffic and peaker power plants which are disproportionately located in and routed through poor communities and communities of color aggravate the public health crises of heat waves. Extreme heat constitutes an environmental justice crisis in cities. In New York City, between 2000 and 2012, half of those who died from heat were black. Most recently the NYC Environmental Justice Alliance and local city council members urged the city to better track heat vulnerability and implement a new $55 million program to provide over 74,000 air conditioners to New Yorkers who are 60 years old and older and have income below 60 percent of the state median income.
The loss of human life from heat waves often surpasses hurricanes, blizzards and other natural disasters. According to the New York City Mayor’s Office, heat leads on average to 450 hospitalizations a year, more than any other weather event. According to researchers at Columbia University, by 2080 deaths from heat in New York City could surpass 3,330 people a year. To put the magnitude of this crisis in perspective, the devastation wrought by Hurricane Sandy took the lives of 285 people across the tristate area. Heat in cities demand mitigation and emergency preparedness commensurate with the risk to public health.
Extreme Heat and Urban Centers in the Covid Era
Cities are complex systems. Potential solutions to urban problems often have unintended effects. How can cities promote cooling centers and adequate social distancing? How can cities open beaches and public pools without spreading COVID-19? How can we ask elderly people to socially distance inside if these apartments overheat? In other cases, novel solutions emerge from the confluence of crises. Could open streets provide the impetus for planting trees whose canopy shades roads and sidewalks? Would this lead to more walking and bicycling and less car exhaust and asphalt cooling further our cities? Could the growth of urban forests offset the urban heat island effect? How do these solutions contribute to mitigating climate change? How are activists and community organizations changing the conversation around emergency preparedness?
How we plan our cities and how we manage risk, which communities may budget for street trees and parks and which communities have trucking and garbage routed through them, determine these impacts. As evidenced by the Urban System Lab, COVID-19 and urban heat disproportionately impact poor communities and communities of color and these impacts are entangled and reinforcing. Highways localize pollution in certain neighborhoods contributing to the prevalence of comorbidities which worsen health outcomes from coronavirus and extreme heat. Disinvestment from hospitals and lack of access to health care or ability to afford premiums denies certain communities treatment. Emergency preparedness in cities must include the slow violence of environmental racism. We must prepare for and respond to urban crises like heat waves and pandemics in ways that rectify structural injustices.
Social distancing measures are proven to reduce the spread of COVID-19. In hotspots, doctors, nurses and EMTs devote themselves to treating COVID-19, hospitals keep beds open, social workers and others in the care economy focus on preparing for and responding to COVID-19. These same people are on the frontline of heat waves and extreme heat in cities. Heat waves require an allocation of similar resources though on a smaller scale. Elderly people and those with comorbidities are more likely to require hospitalization due to heat, and coronavirus and other contagions spread more rapidly in crowded hospitals. Cities with comprehensive plans for these interrelated risks will be better prepared to support and treat vulnerable populations and communities.
Cities typically prepare for the impact of heat through a combination of subsidizing electric bills and providing indoor and outdoor public spaces where people can keep cool. COVID-19 demands people stay in their own homes, or in public places outside with appropriate social distancing. Both of these measures contradict the usual response to heat in the city. Often by the time the full adverse impact of heat is felt already the person is too compromised to transport themselves to the hospital or too disoriented to seek medical attention themselves. Researchers at Tsinghua University in Beijing compared COVID-19 vulnerability to “the Chicago heat wave in 1995, during which those who lived alone or had little social capital were more likely to die from the disaster.” For this reason, community connectivity and the use of public space are essential to addressing the health impact of heat waves and extreme heat.
Heat waves often trigger blackouts which threaten marginalized populations. The demand for air conditioning and the temperature strains the electric grid. Urban heat islands aggravate these conditions. Climate change increases the severity and frequency of heat waves. Socially distanced cities are more reliant than ever on the internet and electric grid for connectivity.
Building our cities around automobiles and not around pedestrians, cyclists and biodiverse greenspaces creates cities which are composed predominantly of asphalt and concrete and where car traffic and parking are prioritized over the right of people and other species to live comfortably and breathe well. Especially in summer as the heat trapping properties of asphalt, concrete and car exhaust become more pronounced. It’s important to note that asphalt is a petroleum based product, so its proliferation in public space subsidizes the fossil fuel industry. Essentially as of now our urban public space subsidizes directly and indirectly fossil fuel conglomerates.
On July 9th, New York City released a cooling plan. Cooling centers will open with limited capacity. Attendees will wear masks and stay socially distanced. Cooler centers may be in high demand with offices closed and cafes and restaurants operating without indoor seating. What if attendance exceeds capacity? In the most heat burdened communities, fourteen open streets will become “cool streets.” These streets, selected in part for the ample shade the trees there provide, will also feature hydrants spraying cold water on hot days. The FDNY will install spray caps to ensure broad spray, borrowing an old trick deployed throughout the boroughs to stay cool. Cool streets, like open streets, only operate during the day, and will provide no respite for New Yorkers during the night when the urban heat island effect is strongest. The city complements cooling centers and cool streets by pushing equitable access to air-conditioning. Greening public spaces like streets and roofs, providing more parks and community gardens, and making space for busses, bicyclists, and pedestrians contributes to cooling the city. Highways and multi-lane roads are sickening and segregating urban communities throughout the country, disproportionately communities of color. Reimagining how cities organize space can be an exercise in restorative justice. So can reimagining our energy system to provide adequate cooling to all people.
Modelling Future Heat Risk
Changes to urban temperature are complex to model. There are gradients neighborhood to neighborhood, block to block, apartment to apartment. Temperature depends on multiple entangled temporal and spatial factors such as sunlight, wind and humidity that interact with the built environment and urban ecology. In coastal cities, sea breezes depend on the temperature gradient between the city and the ocean. Hotter days and nights stiffly sea breezes. Paved surfaces prevent rainwater absorption by soils reducing the cooling evapotranspiration of urban forests. Severe air pollution may worsen heat waves by preventing clouds from forming. On humid days people struggle to perspire, worsening the health impacts of heat. Feedbacks are complex, occasionally contradictory. Broader avenues may allow for more air circulation but also more asphalt and car exhaust. Air conditioning cools apartments while heating and polluting streets. For those without air conditioning towards the end of a heat wave, indoor settings can become hotter than outdoors. Repercussions for public health extend beyond heat waves.
Luis Ortiz is a postdoctoral research fellow with the Urban Systems Lab, who researches urban heat, focusing on New York and San Juan. We spoke with Luis about the risks associated with COVID-19 and extreme heat and equitable and restorative solutions. Ortiz trained as a mechanical engineer and this training prepared him to conceive of cities as complex social, technical and ecological systems, composed of interrelated processes. Luis Ortiz has asked and answered questions about heat in cities on multiple scales. He has modeled citywide temperature dynamics based on a historic heat wave, and developed high-resolution projections of extreme heat in New York City. He has also researched the effects of urban heat on individuals through the use of surveys and body sensors. This gives Luis a unique perspective on the small and large scale complexities of urban heat.
Often closer study reveals counterintuitive aspects of urban heat. Luis Ortiz told us about his research on the heat exposure of eldery people in New York City. “We found that on terribly hot days people were not the most exposed to high temperatures, because those were the days people sought refuge from the heat. This complexity on an individual scale might be invisible on a large scale.”
Ortiz views all of these problems through the lens of environmental justice. “When you look at the whole city, the vast majority of buildings have air conditioning. But then when you start looking at different neighborhoods in particular, some places have much lower levels. What happens is that these neighborhoods which have the lowest levels of adoption also happen to be the neighborhoods with the lowest incomes because they cannot afford to own or operate air conditioning. When you study the environmental impact of giving everybody air conditioning, the increase would be so small in terms of energy consumption, that we could easily offset it. So we can keep the justice part of the policy.” Ortiz mentions a study that showed the neighborhoods with the most essential workers, where the most people were still commuting to work, were also the neighborhoods with the least bike lanes.
Luis Ortiz voices deep concerns about the risks of extreme heat to populations already vulnerable to COVID-19. Especially since extreme heat in cities can make it hotter inside apartments than outside, especially at night and towards the end of heat waves. This means that social distancing and quarantining could harm vulnerable populations if proper precautions are not taken against heat. Ortiz is encouraged by cities taking action. New York City already subsidizes purchase and installation of air-conditioning for LMI communities. This summer the city began giving free ACs to vulnerable seniors. During quarantine, volunteers telephoned seniors to keep them company and check in on their health. This kind of connectivity helps vulnerable communities stay safe during heat waves as well. Luis Ortiz assures us that “it’s just a matter of making sure that the government and policymakers look at this through the lens of social justice.”
Zef Egan is an environmental educator and writer. He is pursuing a master’s focused on Environmental and Social Justice at the Graduate Center. @EganZef
Christopher Kennedy is the Assistant Director at the Urban Systems Lab and a Lecturer in the Parsons School of Design. His work focuses on understanding the socio-ecological benefits of spontaneous urban plant communities in NYC, and the role of civic engagement in developing new approaches to environmental stewardship and nature-based resilience. @chrisleekennedy
Timon McPhearson is the Director of the Urban Systems Lab and Associate Professor of Urban Ecology at the New School. He investigates the ecology in, of, and for cities and teaches urban resilience, systems thinking, and urban ecology. @timonmcphearson
Luis Ortiz is Postdoctoral Research Fellow with the Urban Systems Lab at The New School. A mechanical engineer by training, he is interested in the intersection of built environments, humans, and the atmosphere. In particular, he is interested in how climate change impacts energy use and health, as well as how cities may mitigate and adapt to these impacts. His current work as a member of the UREx SRN project involves projecting vulnerability to weather extremes across a range of stakeholder-driven land use and climate scenarios. @Lortizuriarte
