Scientists predict that as the Earth’s climate changes, it will mean more weather events that cause disease and death – including deadly heat waves.
By Taylor Sisk
In August 2003, more than 35,000 people across Europe died as a result of exposure to extremely high temperatures.
France was hit especially hard – particularly its elderly population – with nearly 15,000 deaths. The Washington, D.C.-based Earth Policy Institute noted at the time that this was more than 19 times the global death toll from the SARS epidemic.
The Earth’s climate continues to change, and, this year’s relatively cooler summer here in North Carolina notwithstanding, temperatures continue to climb.
Montserrat Fuentes, head of the department of statistics at NC State University, has been examining the effects of rising temperatures on human health for more than 10 years. Along with Jingwen Zhou, also of NC State, and Howard H. Chang of Emory University, Fuentes published a paper last September in the Journal of Agricultural, Biological, and Environmental Statistics titled “The Health Impact of Climate Change With Calibrated Climate Model.”
The researchers compared historical data for mortality and high temperatures in the southeastern U.S. – where a particularly dramatic ongoing increase in temperatures is expected – with projected outcomes.
They found that by 2040, if no adaptations are made, extreme temperatures will take an average of five more lives each year than in 2000 in three cities in Alabama: Birmingham, and Huntsville.
Project those numbers for three mid-sized cities across the entire region, then across the globe, and, Fuentes, said, we’re facing a considerable crisis.
“Our study shows the serious challenges and human health consequences for cities around the world associated with climate change,” she said.
These findings, Fuentes said, are “an urgent call for adaptation efforts to mitigate the human health impacts of climate change.”
Beyond the effects on physical health, Chris Fuhrmann, a climatologist with the Southeast Regional Climate Center said we must consider consequences of extreme heat on the incidence of violence, depression and suicide, and on productivity too.
Adapt, or else
Fuentes acknowledges that people will most probably make adaptations in response to rising temperatures – spending more time indoors and designing homes differently, for example – as will governments. Certain regions, she said, may no longer be deemed inhabitable.
“It’s difficult to project what type of adaptations we would use in the future,” Fuentes said. “We’re trying to bring an awareness that if we continue to do things the way we are now, we can expect an increase in mortality.”
Her research found that while between 1991 and 2000 Birmingham experienced an average of 4.1 days in which temperatures rose above 98.6 Fahrenheit, between 2041 and 2050 the city is projected to have 54 such days.
But the primary concern, Fuentes said, is with heat waves, which for her research purposes are defined as two or more days of extreme heat.
Between 1991 and 2000, Birmingham had an average of 0.9 heat waves; between 2041 and 2050, 44 heat waves are expected.
“The most important thing is to understand that we’re expecting to have not just an increase in temperatures, but these temperatures will remain high for several consecutive days,” Fuentes said, “and that will have a very adverse effect on human health.”
Fuhrmann said that seasonal cycles in behavioral health issues have been identified, and that it’s important going forward to raise awareness of the potential for extended high temperatures to affect our states of mind.
“There have also been some longitudinal studies that have looked at the effect of temperature on gross domestic product,” he said, which have indicated a decline in productivity when temperatures climb.
Don’t be fooled
There have been significantly fewer days than normal this summer in which the maximum temperature in the southeast has been above 95 degrees.
But don’t let that fool you into thinking the general trend has turned, Fuhrmann advised.
There’s a meteorological explanation for the relatively warmer temps across the country – a ridge in the west that’s made it warm and dry there, and a trough in the east that’s made it cooler and wetter here.
(Fuhrmann also pointed out though that while our highs this summer have been relatively lower, our lows have been relatively higher: cloud cover and moisture have tended to keep the temperatures up at night.)
“There’s nothing terribly unusual about how this summer has progressed,” Fuhrmann said.
“We have no idea what’s going to happen in the next 100 years,” he said, “but we can begin to say some things about what might in the next couple decades.
And that is that the heat of the summer can be expected to continue to grow more oppressive.
Funding for coverage of environmental health issues provided by the Park Foundation.