scope & limitations

According to scientists from the National Oceanic and Atmospheric Administration, July 2019 was the hottest month ever recorded on Earth.

In New York City, July 20, 2019 was the hottest day of the summer, with city wide temperatures reaching highs from 95 to 99 degrees fahrenheit and humidity levels at 70% or more. (5,6)

Our research covers the five boroughs of New York City, focusing on that particular July day. The latest ACS estimates from 2017 allow us to evaluate demographic data about the people most vulnerable to these situations of extreme heat.

During periods of anticipated extreme heat, New York city provides access to a number of cooling centers dispersed throughout the city. “Cooling centers are air-conditioned spaces such as senior centers, community centers, public libraries, and other public facilities that typically operate during daytime hours and are free and open to the public.” (7)

The first step consists of mapping relative surface temperatures using LandSat8 data. Meanwhile, aggregating a series of social indicators to census blocks, allow us to locate the census blocks with the most vulnerable populations. Once these two indicators are in place, the spatial relationship between the location of vulnerable populations and urban heat islands becomes apparent.

This leads to the following question : What is the proximity of New York City cooling facilities to census blocks with the highest levels of vulnerability to heat? Given future rises in temperature due to climate change, should the city increase the number of these facilities to alleviate heat in these neighborhoods?

Our research is not without limitations. Given the scope of our study, we needed to define what constitutes an urban heat island. In practice, the horizontal features taken into account in land cover data are water, vegetation, density and impervious surfaces. Yet other variables could also be taken into consideration, such as the vertical reflectivity of build- ing materials, the presence/absence of green roofs, as well as buildings’ greenhouse gas emissions. These elements would be worth considering in order to further this research. (8)

Additionally, the surface temperature raster retrieved from the LandSat8 scan only shows relative heat. Converting this relative heat into actual temperatures in degrees Celsius or Fahrenheit was outside our purview.

On another note, New York City only makes the location of accessible cooling centers known during expected heatwaves. Given our timing, we could not retrieve data regarding the type and location of these designated cooling centers. For the purposes of our study, we used NYC Open Data’s Facilities database, operationalizing senior centers and community centers as ‘guaranteed’ cooling centers. Not knowing which of the New York City Public Libraries were previously used as cooling centers, and due to their shear numbers, we initially excluded them from our cooling centers. We later reincorporated them in our study.