Matt McGrath, BBC, May 25, 2021
A new study says that black people living in most US cities are subject to double the level of heat stress as their white counterparts.
The researchers say the differences were not explained by poverty but by historic racism and segregation.
As a result, people of colour more generally, live in areas with fewer green spaces and more buildings and roads.
These exacerbate the impacts of rising temperatures and a changing climate.
Cities are well known magnifiers of a warmer climate.
But, within cities, there are often large differences in this heat island impact, with areas rich in trees and green spaces noticeably cooler than those that are dense with housing and industry.
A previous study in the US found a correlation between warmer neighbourhoods in big cities with racist housing practices dating back to the 1930s.
This new study takes a broader look at these warmer neighbourhoods and the people who are affected by them.
Using satellite temperature data combined with demographic information from the US Census, the authors found that the average person of colour lives in an area with far higher summer daytime temperatures than non-Hispanic white people.
For the purposes of the paper, the scientists defined “people of colour” as including all Hispanic people (regardless of race) and anyone who does not identify as white alone.
In all but six of the 175 largest urbanised areas in the continental US, people of colour endure much greater heat impacts in summer.
For black people this was particularly stark. The researchers say they are exposed to an extra 3.12C of heating, on average, in urban neighbourhoods, compared to an extra 1.47C for white people.
Exposure to heat not only leads to to increased mortality, it is also connected to a range of impacts including heat stroke, loss of productivity in work and impaired learning.
In the paper, the authors reflect on the fact that planting trees in heat-stressed areas can reduce summer temperatures by 1.5C, which is good for residents.
But the new trees can also increase property values and these house price effects can end up displacing the minority residents the policies were designed to help.