‘Killer Summer Heat’ Report Grabs Attention

It’s one thing to project that climate change will bring more intense and more frequent heat waves as we move through the 21st century, which climate scientists do. It’s another and more meaningful thing to put a number on the toll this will take on people — and that’s what a new report from the Natural Resources Defense Council has done. Titled “Killer Summer Heat,” it combines population projections and heat projections to calculate the likely number of extra deaths due to heat in America’s 40 biggest cities.

The number comes out to more than 150,000, many of them elderly, and especially among those with cardiovascular disease, kidney disease, lung disease and other ailments common to older people.

By coming up with actual numbers and breaking them down by city, the authors managed to grab peoples’ attention in a way some vague statistic wouldn’t have done. “Killer heat projected in Minneapolis by end of century,” proclaimed the headline in the Minneapolis Star Tribune, whose story led with the fact that “the Twin Cities are could see eight times as many deaths due to extreme heat as it does now.” In Detroit, the Free Press announced: “Metro Detroit to see spike in heat-related deaths unless action is taken, study says,” noting that Motown is projected to have the second-highest increase, with nearly 18,000 extra deaths by 2100, after Louisville.

That dubious honor did not escape Kentucky’s largest city, where the Courier-Journal reported: “As many as 19,000 Louisville residents will die of heat-related causes by the end of the century — topping 40 large American cities, according to a new environmental report.” The story went on to explain that the NRDC estimates the current rate of heat-related deaths at 39 per year; the rate by 2050 could soar to 257 annually in 2050 and 376 by 2100, for a grand total over the century of nearly 19,000 extra deaths. In Cleveland, meanwhile, which came in at No. 3, the online Cleveland Leader broke the bad news to locals that the city can expect more than 16,500 extra deaths by century’s end thanks to climate change.

As most of the coverage notes, NRDC’s grim projections are based on one important assumption: that the amount of heat-trapping CO2 and other greenhouse gases in the atmosphere will double by the end of the century. This isn’t inevitable — but given the lack of significant action taken so far, it’s a pretty plausible assumption.

To see if where you live is on the list, and how many local deaths you can expect, NRDC has put together a table showing figures for all 40 cities in the study.