A deadly wave heart attacks and strokes are headed to the United States, driven by extreme heat waves driven by climate change — and these deaths are more likely to occur among older or black people.
In the middle of the century, according to research published Monday, cardiovascular deaths linked to extreme heat could triple, to nearly 5,500 additional deaths per year, if nothing is done to reduce greenhouse gas emissions that cause climate change and episodes extreme heat. And even if the United States were to control its emissions by continuing its current reduction trajectory, cardiovascular deaths would more than double, to 4,300 additional deaths per year. Through the combined influences of age, genetic vulnerability, geography, and heat-trapping aspects of urban development, investigators predict that older adults will be at higher risk and that black adults will be at higher risk than any other group.
“The public health impact of climate change affects individuals who live at the margins of our society,” says Sameed Khatana, a cardiologist and assistant professor at the Perelman School of Medicine at the University of Pennsylvania. “Any policy action or mitigation effort must truly be tailored to the most vulnerable individuals. »
The prediction comes from Khatana’s group at the University of Pennsylvania, which previously modeled the relationship between current deaths from heart attacks and strokes and the increasing number of “extreme heat days” (possessing a heat index – a measure of apparent temperature that is a product of ambient temperature and relative humidity – equal to or greater than 90 degrees Fahrenheit). Using data from all 3,108 counties in the contiguous United States between 2008 and 2017, they found an increase in cardiovascular death rates as well as a trend toward an increasing number of extreme heat days. In 2019, they said, there were 54 days of extreme heat per year, and each year 1,651 people died.
This currently represents a small proportion of all cardiovascular deaths in the United States. But given that heat events are expected to increase with climate change, they thought it was worth asking how temperature increases would affect death rates. The results were dramatic.
To produce the new analysis, they combined previous work with predictions of rising global temperatures, migration to warmer parts of the United States, and the aging of the U.S. population, as well as demographic changes that will distance the majority of the population from white people. not Hispanic. The team then plotted the likely effects of these combined factors in two scenarios. In one, the United States manages to keep greenhouse gas emissions at a moderate increase, a scenario known as RCP 4.5 that represents existing policies that could be implemented . In the other, known as RCP 8.5, emissions are increasing virtually unchecked.