PNNL

Abstract

The roots of intra-urban heat disparity often extend beyond contemporary factors, stemming from past discriminatory practices such as redlining. Here, we compare the relative impact of historic redlining and present-day income inequality on the thermal disparity of Los Angeles. The salient aspect of our work is the use of land surface temperatures from the ECOSTRESS instrument aboard the International Space Station. This allows for the detection of diurnal trends in intra-urban thermal disparities caused by redlining. Notably, we find that present-day income inequality proves to be a stronger indicator of heat burden than historic redlining itself. Moreover, the temperature disparities demonstrate a seasonal hysteresis pattern and amplify during heat waves by up to 5-7°C. Socio-demographic analysis highlights that Hispanic populations in historically and economically disadvantaged areas are often the most vulnerable. Our findings suggest that while the legacy of redlining may persist, the present-day heat disparities are not necessarily an immutable inheritance, where targeted investments and interventions can pave the way for a more thermally just future for these communities.