Why poorer American neighbourhoods have fewer trees and higher temperatures
Environment — di Cecilia Dardana
According to a study, low-income neighbourhoods have fewer trees and higher temperatures than wealthier ones, due to past policies.
Why poorer American neighbourhoods have fewer trees and higher temperatures
According to a study, low-income neighbourhoods have fewer trees and higher temperatures than wealthier ones, due to past policies.
Number of trees and temperatures: these are the new thermometer of inequality in several American cities. Higher average temperatures and a scarce presence of trees indicate that one is in a low-income neighbourhood. This is the finding of a two-year study, published in the scientific journal Plos one and conducted by a team of researchers from Nature Conservancy, which highlighted how the distribution of trees and the climate of urbanised areas often depend on the ethnicity and social class of their inhabitants. As if to say: the less money you have, the less greenery there will be in your streets. But this is nothing other than the result of discriminatory laws, racial segregation and an unequal distribution of wealth in the country.
The correlation between income, tree cover and temperatures
Green spaces in cities offer undeniable benefits for the health and wellbeing of residents. But according to the study's findings, tree cover is often distributed unequally. Using digital orthophotos from the National Agriculture Imagery Program, the researchers examined the presence of trees in 5,723 municipalities across the major urbanised areas of the United States, home to around 167 million people. They then compared this with summer land surface temperature. The result? 92 per cent of low-income neighbourhoods in the United States have lower tree cover (15.2 per cent less) and higher average temperatures (around 1.5 degrees more) than high-income blocks.
Tree inequality in widespread and pervasive in US cities. Our new survey of almost 6000 US communities is out in PLoS One: doi.org/10.1371/journa…
The inequality is most widespread in the north-east of the United States, where some low-income areas record as much as 30 per cent less tree cover and average temperatures 4 degrees higher than high-income zones. Five of the ten most striking cases are found in Connecticut, home to the country's most economically unequal metropolitan area and known as one of the states with the greatest socioeconomic segregation in America.
Estimates suggest that the poorest neighbourhoods have 62 million fewer trees than the wealthiest ones. Translated into money: this represents a value of 56 billion dollars less, or 1,349 dollars per person. Bridging the gap would require an investment in tree planting and natural regeneration of 17.6 billion dollars, to the benefit of 42 million people.
The effects of past economic and social policies
"We knew this inequality existed," explained Robert McDonald, scientist at Nature Conservancy and head of the research, "but we wanted to see the full picture, especially because heatwaves are becoming more frequent and more intense. So understanding which neighbourhoods are most vulnerable is the first step towards reducing the harm." The research, McDonald adds, aimed to explain how past economic and social policies had effects even on unexpected aspects of American life. Historically, racist policies made it virtually impossible for Black and Latino people to buy a home and also made economic and social mobility difficult, forcing them to live in heavily polluted and more densely populated neighbourhoods.