People working in jobs without air conditioning will need to take breaks twice as often by 2050 to avoid heat stress amid a warming climate, according to a study by the National Oceanic and Atmospheric Administration.
Losses in labor capacity, or the ability to work safely in warm conditions, will double by mid-century assuming global temperatures rise by 1 degree Celsius (1.8 degrees Fahrenheit), according to the study published yesterday in Nature Climate Change. Temperatures have risen 0.7 degrees since before the Industrial Revolution in the 1800s.
“The planet will start experiencing heat stress that’s unlike anything experienced today,” Ronald Stouffer, a physical scientist at NOAA’s Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey, and co-author of the report, said on a conference call with reporters. “The world is entering a very different environment and the impact on labor will be significant.”
The study, which covers work outdoors at night and in the shade and indoor work without air conditioning, uses guidelines set by industry and the military for a safe workplace in hot conditions. Today, people working when temperatures peak must rest about 10 percent of their working time. That will double to 20 percent by 2050, according to the study.
The study excludes heat stress from working directly under the sun.
“This effort changes the scope of the climate-change debate by putting the direct human impact in practical terms,” said John Dunne, who leads the Biochemistry, Ecosystems and Climate Group at the Princeton laboratory and the study’s lead writer. “It relates to anyone working without the benefit of air conditioning and would be a minimum estimate of heat stress for anyone working in an elevated heat environment, such as a kitchen or furnace.”
Last year was the world’s 10th warmest on record going back to 1880 with an average temperature of 58.03 degrees, according to NOAA’s National Climatic Data Center in Asheville, North Carolina. It was the 36th consecutive year to exceed the 20th- century average of 57 degrees.
Under the worst projections for warming that see global temperatures rising 6 degrees by 2200, heat stress levels in places such as New York City and Washington, D.C., would exceed those seen in Bahrain today, according to the study. In such conditions, people working without air conditioning would need to rest about 75 percent of the time, Dunne said.
“Extreme projections of global warming of 6 degrees eliminates all labor capacity in the hottest months in many areas, including the lower Mississippi Valley, and exposes most of the U.S. east of the Rockies to heat stress beyond anything experienced in the world today,” Dunne said.
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