New data, compiled by the Union of Concerned Scientists [UCS] found that between 1971 and 2000, US counties with more than 25% black populations suffered an average of 18 days each year when the heat index soared above 100F (38C). In counties where less than a quarter of the population was black, there were an average of seven days per year over 100F.
By 2050, if no global action is taken to reduce greenhouse gas emissions, US counties where more than a quarter of residents are black will battle 72 days a year with temperatures over 100F compared to 36 days in counties where fewer black people live.
And by mid-century, there will be an average of 43 days each year where the heat index is above 105F (40F) in counties with greater black populations, compared to 21 days in areas that are less than 25 per cent black.
Hispanic communities will also face longer and more intense heatwaves. Counties with more than 25 per cent Hispanic/Latinx residents, historically faced an average of three days per year with a heat index above 105F. In another 30 years, this will rise to 27 days a year if emissions continue to rise.
Overall, minority and poor communities disproportionately bear the brunt of pollution and the climate crisis, with extreme heat posing a potent risk.
Black communities’ exposure to extreme heat is a factor of systemic racism that can be traced back to America’s history of slavery.
Dr Kristina Dahl, a senior climate scientist with UCS who conducted the analysis, told The Independent: “Communities with relatively large Black or Latinx populations are located primarily in the southern half of the US, which includes some of the country’s hottest places, such as Florida, Mississippi, Arizona, and Texas. These patterns reflect the country’s history. The concentration of Black people — and their disproportionate exposure to extreme heat historically and in the future — in the Southeast reflects one of the many ways that the legacy of slavery in the US contributes to the higher vulnerability of Black people to environmental stressors like heat.”
For Latin communities, their exposure can be linked in part to agricultural work. “Hispanic and Latino populations tend to be concentrated in areas where their labour has been critical to our nation’s food supply, such as California’s Central Valley. These places, too, tend to be hot,” Dr Dahl said.
A study, published in June by Boston University School of Public Health, found that thousands of deaths each year in the US are attributable to heat, far greater numbers than the 600 fatalities estimated by the CDC. Researchers estimated that heat was a factor in the deaths of 5,600 people each year on average from 1997-2006 in 297 US counties.
A sweeping study of US residential carbon footprints, published last week in the Proceedings of the National Academy of Sciences, also found that wealthy Americans produce almost 25 per cent more heat-trapping gases at home than those with lower incomes.
The study analysed 93 million homes to gauge the levels of greenhouse gases being pumped out in different locations and by income. Residential carbon emissions comprise close to one-fifth of global warming gases emitted by the burning of coal, oil and natural gas.
Researchers found that energy use by the average higher income person’s home puts out 6,482 pounds of greenhouse gases a year. For a person in the lower income level, the amount is 5,225 pounds, the study calculated.
Intense heat waves are on the rise globally. A 2019 study found that extreme heat events in the Northern Hemisphere “would not have occurred without human-induced climate change”.
“A strong reduction in fossil fuel emissions is paramount to reduce the risks of unprecedented global-scale heat wave impacts,” the study noted.
Global temperatures in 2020 are on track to be the warmest on record. NOAA’s State of the Climate report this month found that the first six months of 2020 were second warmest only to the same period in 2016.
In July, heat warnings and advisories were issued for at least 11 states with record-breaking temperatures were documented in disparate regions. In California’s Death Valley, the mercury hit 128F earlier this month, the highest recorded temperature on the planet since 2017.
Extreme heat, particularly in the Southwest, is causing additional risks as the coronavirus pandemic continues to rage. Heatwaves worsen the health concerns of those with underlying conditions, particularly older people and poorer communities who may lack air conditioning to combat extreme temperatures.
Studies have also shown that communities of colour and indigenous peoples are at increased risk of falling ill and dying from Covid-19.
AP contributed to this report
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