The U.S. Is Undercounting Climate-Driven Deaths

“The system of death surveillance wasn’t designed for a climate-changed world.”

by Zoya Teirstein, Grist

Every week between May and October, the Maricopa County Department of Public Health in Arizona releases a heat morbidity report. The most recent report said that 180 people have succumbed to heat-associated illness in the county this year so far. But everyone agrees that number is off.

If previous years are any indication, the true number of heat-related deaths in Maricopa County, which includes Phoenix, is much higher: At the end of last summer, the county revised its initial reports upwards by a factor of five, ultimately reporting a sobering 425 heat-related deaths in total.

Migrants use cardboard boxes to shield themselves from the sun's heat during the early afternoon on the Roosevelt Hotel migrant waiting line

This lag plagues not just heat-related mortality reporting, but climate-related death data in general. It’s hard to get a full picture of the true number of mortalities connected to a given disaster in real-time. The full death toll often isn’t revealed until weeks, months, even years after the event occurs. And an unknown fraction of deaths often slide by undetected, never making it onto local and federal mortality spreadsheets at all. For example, a recent retrospective study found the number of people who died from exposure to hurricanes and tropical cyclones in the U.S. in the years between 1988 to 2019 was 13 times higher than the federal government’s official estimates.