Report reveals inequities in the exposure to the urban heat island in New York City

New York City experiences higher temperatures in the summertime compared to nearby rural areas due to the large area of heat-absorbent paved surfaces and buildings, and lack of greenspace – a phenomena called Urban Heat Island effect. A new report shows that extreme summertime heat is distributed unevenly throughout the city and that it disproportionately impacts Black and Latino communities in Northern Manhattan.

The report — Summer In The City: Improving Community Resilience To Extreme Summertime Heat In Northern Manhattan – was released today by WE ACT for Environmental Justice and NRDC (Natural Resources Defense Council). It provides an overview of current and projected extreme heat fueled by climate change in New York City; reveals the results of a first of its kind community heat survey on how residents of Northern Manhattan neighborhoods experience and cope with the extreme heat; examines census data to map the demographics of those populations most vulnerable to extreme heat, and satellite data on green, vegetated areas versus heat-absorbing human-made surfaces; discusses the health burdens that extreme heat imposes on environmental justice communities; and provides policy recommendations that reflect and address the concerns and experiences of those most affected by extreme heat. 

The full report is here, and key findings are summarized below.

“The threat that the Urban Heat Island effect poses to public health, especially for people of color, will only grow as climate change intensifies this phenomenon,” said Kim Knowlton, senior scientist at NRDC. “Inequity in health outcomes from extreme heat is an environmental injustice. We must enact solutions that correct the problem and help tackle climate change.”

“This report reveals the health threats that low-income communities and communities of color face during summer heat waves in cities like New York. And with the added threat of COVID-19, which has killed Black/African Americans at about 1.5 times more per 100,000 people than white people, summer heat waves are an added health burden on New York's most vulnerable communities,” said Sonal Jessel, Director of Policy at WE ACT for Environmental Justice. “That is why we need the City and the State to work together to pass legislation that protects these communities from the threat of extreme heat events, which are increasing in frequency, intensity, and duration due to the climate crisis.”

“Understanding how residents experience extreme heat is crucial to developing policies and practices that reduce the very inequitable human health burdens from the Urban Heat Island,” said Juan Declet-Barreto, social and environmental scientist. “The community survey in the report provides a necessary look into how residents of Northern Manhattan cope with summertime heat.”

In part due to patterns of racial discrimination and segregation, concentrated poverty, and public and private disinvestment, populations in New York City that are already vulnerable to poor health outcomes are also overburdened with higher death and illness rates from extreme heat. Exposure to high temperatures varies considerably according to land surfaces within a city, and in New York City, people of color often live in areas characterized by little canopied vegetation and abundant heat-retaining surfaces like dark pavements, roofs and building materials.

KEY FINDINGS

We surveyed nearly 500 residents of Northern Manhattan neighborhoods during the summers of 2014 and 2015 and asked them questions about their experience with extreme heat.

Community heat survey key findings:

• Nearly 87% of respondents to a community heat survey said that heat waves were very serious or somewhat serious risks, and nearly 81% thought that urban heat islands posed very serious or somewhat serious risks.
• People surveyed said they relied most often on air-conditioning window units at home, indoor fans, and drinking lots of fluids to cope with heat. But while 40% of respondents said they had no issues with using air conditioning to cool their homes, almost as many (37%) reported barriers, such as lack of an air-conditioning unit or the cost to purchase, repair or operate an air conditioner at home.
• Notably, the use of public cooling centers was mentioned by just 17% of respondents.

The report also includes maps of the hottest parts of Northern Manhattan and the most heat-sensitive populations, and then combines them to map the cumulative vulnerability of the area to help us understand how the vulnerability to heat-related illness or death can vary among neighborhoods with different levels of sensitivity and heat.

Heat vulnerability mapping key findings:

• According to our analysis, most of the Inwood area in northern Manhattan has both high exposure and residents have high sensitivity to heat, contributing to residents’ risks of suffering a heat-related health problem(as the result of pre-existing conditions and/or lack of resources to cope)
• In portions of East Harlem, the heat sensitivity of the population is high, while heat exposure is low, and therefore those areas are considered to have low to moderate heat vulnerability.
• The southwestern portion of West Harlem has both low sensitivity and low exposure, and therefore people in those neighborhoods have a lower likelihood of becoming ill from extreme heat.

Communities of color and low-income communities have been historically excluded from important conversations and policy discussions about extreme heat and climate vulnerability that affect their lives and neighborhoods. Creating partnerships among environmental justice communities, local grassroots environmental organizations, scientists and national environmental organizations is an important step toward achieving an inclusive and participatory policy process that develops solutions that prioritize the needs of heat-impacted communities.

Based on our findings on extreme heat-vulnerable populations in Northern Manhattan, WE ACT and NRDC believe there are several policy steps that would lessen the effects of extreme heat among these populations, including:

• Increase vegetation and the number of trees in high heat vulnerable neighborhoods in New York City to help mitigate the urban heat island.
• Pass New York City bills designed to address extreme heat issues, like WE ACT’s Cooling Centers Wayfinding Bill.
• Engage with New York State lawmakers to create or improve existing policies and programs, including Home Energy Assistance Program (HEAP) reform subsidies for air conditioner use, and enacting WE ACT’s Energy Efficiency Equity and Jobs Act.