Eastern US Headed for Many More Extreme Heat Waves With Warming, Study Finds
Sunday 15 August 2010
Washington D.C. is projected to see 100 summer days above 90 degrees by 2050, if emissions continue unabated.
Washington - When "snowmageddon" buried the nation's capital in February, Sen. Jim Inhofe's grandchildren delved into the record-shattering drifts to construct an igloo near the U.S. Capitol.
They jokingly labeled it Al Gore's new home.
Six months later, the thought of taking refuge in an icy shelter is quite appealing to heat-weary Washingtonians. While the Oklahoma Republican senator used the igloo to tweak the former vice president and as a prop in his relentless crusade to prove global warming a hoax, climate scientists are once again emphasizing that current and upcoming weather extremes are no laughing matter.
Oppressive temperatures gripping Southern and Eastern U.S. states this summer will only worsen if little is done to curb greenhouse gases, according to an August report update from the National Wildlife Federation (NWF), a conservation group.
"2010 is a sample of what's to come," said Amanda Staudt, lead climate scientist for the report titled "Extreme Heat in Summer 2010: A Window on the Future."
"Global warming is bringing more frequent and severe heat waves, which will seriously impact vulnerable populations."
It is a supplement to the federation's 2009 report "More Extreme Heat Waves: Global Warming's Wake-Up Call."
This hot summer is a continuation of what the National Oceanic and Atmospheric Administration says is already the hottest January through June on record. New Jersey, Delaware and North Carolina have already recorded their hottest June ever and Rhode Island and Delaware have recorded their steamiest July, according to NOAA. Hundreds of daily temperature records were set across the country — with July being among the top five hottest on record for 10 Eastern states.
Through Aug. 11, Washington has already dripped its way through 51 days where temperatures were 90 degrees or higher; twenty of those days have been 95 degrees or higher, according to data published on the Washington Post's Capital Weather Gang.
Typically, Washington has 18 days through July 31 with temperatures above 90 degrees. This year, that number had more than doubled — to 39 — by the end of July.
And Washington is by no means alone. The federation's analysis of large cities on the Eastern seaboard shows most locations have had roughly twice as many days with temperatures exceeding 90 degrees than they typically would by the end of July. Cities in the south-central United States also are running hot.
"For each of these cities ... sweltering the last couple months, summer 2010 could be considered mild compared to the typical summers of the future," the report's authors state.
The report explains how summers such as this one could become the norm by mid-century if carbon dioxide emissions aren't brought under control.
For instance, Washington is projected to sweat through 100 summer days above 90 degrees by 2050 if emissions continue unabated. That number could hold steady at about 55 days, however, under a lower-emissions scenario.
The report's predictions in Philadelphia and St. Louis are equally alarming. Through the end of July, Philadelphia has had 25 days above 90 degrees and that number is predicted to grow to at least 55 by year's end. St. Louis is on track for 45 extremely hot days this year, about 10 above average.
By 2050, Philadelphia is projected to have 40 days above 90 degrees under a low-emissions scenario and 60 such days with high emissions. St. Louis is projected to have 60 days above 90 degrees under a low-emissions scenario and 80 such days if emissions are unabated.
Using maps from the U.S. Global Change Research Program, the report shows how end-of-the century climate predictions are even more dramatic if heat-trapping gases are unchecked. Days with temperatures above 90 degrees could double between now and 2099. That would leave much of the South almost unbearable for three or four months when temperatures rarely — or ever — dip below 90 degrees.
"We need to take these trends toward more extreme heat waves into account when designing urban areas and public health programs," Staudt said. "We can no longer plan based on the climate we used to have."
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