Summer 2012: Not An Anomaly But The New Normal
ST. LOUIS (KMOX) – As you sweat out another long hot summer day, here’s a headline you don’t want to see: “St. Louis Heat Waves More Than Doubled Over Last 60 Years”.
But that’s what arrived in the email at KMOX News, and the ensuing press conference revealed that a group called the Union of Concerned Scientists (UCS) had conducted a study going back six decades showing that the city of St. Louis averaged three heat waves per summer in the 1940’s, but now suffers an average of seven.
“Deadly heat waves have become more common in St. Louis because the city’s weather has changed,” said Larry Kalkstein, lead report author and a University of Miami professor. “More hot, dry air masses from the Southwest and hot, humid air masses from the Gulf of Mexico and Caribbean Sea are intruding and settling over the city. During the past 60 years these oppressively hot air masses have not only become more frequent, they have warmed significantly, which can threaten human health.”
Indeed, more than two dozen St. Louis-area residents have succumbed to the heat this summer, the highest total since more than 150 died during the summer of 1980.
After reviewing the data in the report, St. Louis Health Department director Pamela Walker said this warrants a complete rethinking on strategy for preventing heat deaths.
“I think the study reinforces much of our thinking that this is something we’re going to deal with every year in St. Louis city,” she explained. “It’s not going to go away.”
She says that means preparing ahead of time for severe heat, just like they do for the flu and other perennial health threats.
“We must treat prolonged periods of extremely high temperatures as the new norm,” Walker added. “We should come to expect it every year and we will dedicate more time and resources to plan for these types of situations all year long to keep people safe and healthy during extreme weather.”
Todd Sanford, a UCS climate scientist and a co-author of the report, said at least in past summers St. Louisans could count on a big break in the heat once the sun went down.
“Nighttime cooling is critical for reducing heat stress from higher daytime temperatures,” Sanford said. “However, in St. Louis temperatures on hot, humid nights have actually risen (over the past 60 years) by just over two degrees Fahrenheit, while 3 am temperatures on hot, dry nights are also going up and are now on average about four-and-a-half degrees higher than they were about sixty years ago.”
More bad news in the study: the number of days when extremely hot, humid air masses that can cause health problems appeared over St. Louis doubled between 1946 and 2011, going from an average of six to 15.
In addition the city lost four cool, comfortable summer days on average, compared to the seven days it enjoyed during the 1940’s.
To read the full report from the Union of Concerned Scientists, go to www.ucsusa.org.