As temperatures continue to rise, so will the number of deaths each summer, according to a new analysis published online in advance of a print article in Occupational and Environment Medicine.
The increase in summer deaths due to global warming, however, will not be offset by milder temperatures in the winter, concluded the Harvard University researchers who did the analysis.
This is because global warming not only causes warmer temperatures, but also triggers extreme temperatures. Researchers found during two-day cold snaps in the winter there was a 1.59 percent increase in deaths because of extreme temperatures.
They also found that during periods of extremely hot weather death rates went up by 5.74 percent. Deaths did not rise as steeply when temperature fluctuations were less extreme.
For the study, researchers analyzed data related to the deaths of more than 6.5 million people in 50 U.S. cities between 1989 and 2000.
Many Ignore Heat Warnings
Oppressive summertime heat claims hundreds of lives each year. From 1999 to 2003, the Centers for Disease Control and Prevention reported 3,442 deaths resulting from exposure to extreme heat.
But a recent study, funded by the U.S. Environmental Protection Agency, found that heat warnings implemented in four cities, Dayton, Ohio; Philadelphia, Phoenix and Toronto, did little to spur action on the part of residents.
Specifically targeting residents 65 and older, Dr. Scott Sheridan, a Kent State associate professor in geography and the study’s author, found that almost 90 percent were aware when a heat warning was issued in their city, but only half took action.
Air Conditioning May Help
The authors concluded that cold-related deaths have not increased as much as heat-related deaths due to the widespread use of central heating in the U.S. Because central air conditioning is not as widespread, deaths from heat continue to rise at a higher rate, they wrote in the analysis.
But the increased use of air conditioning would help humans survive the heat, while hurting the environment, the researchers said.
"Making air conditioning universally available may reduce heat-related mortality but would, on the other hand, have a perverse effect by enhancing global warming through carbon dioxide emissions from electricity consumption," the authors wrote in the analysis.