Government Scientists: Climate Change Slashing Labor Capacity

[HuffingtonPost]

By Environment Correspondent Deborah Zabarenko                

WASHINGTON, Feb 24 (Reuters) - Earth's increasingly hot, wet  climate has cut the amount of work people can do in the worst  heat by about 10 percent in the past six decades, and that loss  in labor capacity could double by mid-century, U.S. government  scientists reported on Sunday.                

Because warmer air can hold more moisture than cooler air,  there's more absolute humidity in the atmosphere now than there  used to be. And as anyone who has sweltered through a hot, muggy  summer knows, it's more stressful to work through hot months  when the humidity is high.                

To figure out the stress of working in hotter, wetter  conditions, experts from the National Oceanic and Atmospheric  Administration looked at military and industrial guidelines  already in place for heat stress, and set those guidelines  against climate projections for how hot and humid it's likely to  get over the next century.                

Their findings were stark: "We project that heat  stress-related labor capacity losses will double globally by  2050 with a warming climate," said lead author John Dunne of  NOAA's Geophysical Fluid Dynamics Laboratory in Princeton.                

Work capability is already down to 90 percent during the  most hot and humid periods, Dunne and his co-authors wrote in  the journal Nature Climate Change. Using a middle-of-the-road  projection of future temperature and humidity, they estimate  that could drop to 80 percent by 2050.                

A more extreme scenario of future global warming, which  estimated a temperature rise of 10.8 degrees F (6 degrees C),  would make it difficult to work in the hottest months in many  parts of the world, Dunne said at a telephone briefing.                

Labor capacity would be all but eliminated in the lower  Mississippi Valley and most of the United States east of the  Rocky Mountains would be exposed to heat stress "beyond anything  experienced in the world today," he said.                                

BAHRAIN-ON-THE-HUDSON?                

Under this scenario, heat stress in New York City would  exceed that of present-day Bahrain, while in Bahrain, the heat  and humidity could cause hyperthermia - potentially dangerous  overheating - even in sleeping people who were not working at  all.                

Humans are endothermic creatures, which means they give off  heat. If they can't get rid of it faster than they create it,  they go into hyperthermia. Typically, humans cool off by doing  less heat-producing activity, but it may get so hot and humid  that even a sleeping person wouldn't be able to dissipate heat  fast enough.                

"This planet will start experiencing heat stress that's  unlike anything experienced today," said Ronald Stouffer, a  co-author of the study.                

The only way to retain labor capacity, Dunne said, is to  limit global warming to less than 5 degrees F (3 degrees C).                

Global average temperature has risen by about 1.2 degrees F  (0.7 degree C) compared to pre-industrial times. It is likely to  rise another 1.8 degrees F (1 degree C) by mid-century, Dunne  said.                

The way some workers already adapt to heat stress - taking a  siesta during the hottest hours of the day, working outdoor jobs  like construction at night when temperatures drop or ceasing  work entirely during periods of peak heat and humidity - could  migrate to places where heat stress is increasing.                

The U.S. West Coast and Northern Europe are likely to be two  of the regions that will be affected last by the trend toward  more hot and humid climate, the scientists said.                

Part of the issue is how well-adapted certain regions are to  extreme heat stress, Dunne said.                

As an example, he noted that some 70,000 people were killed  during a disastrous 2003 heat wave in Europe, where heat stress  was highly unusual. However, the same kind of stress was normal  for a place like India, where a similar heat wave killed 3,000.                

"It's very regionally dependent and highly determined by  adaptation," Dunne said.     (Reporting by Deborah Zabarenko; Editing by Eric Walsh)

Via: HuffingtonPost