Extreme heat exposure up 4 to 6 times by mid-century

Extreme heat exposure on the rise

Heat kills. Vulnerable populations, like the elderly and children, are highly affected -- but the hazard extends to workplaces too, where heat has significant economic costs in addition to costing otherwise healthy workers their lives each year.

I came across a new study by The University Corporation for Atmospheric Research (UCAR) on the same day I found the usual late Spring reminder on the issue of heat hazards in the workplace in my email. The folks at Industrial Safety and Hygiene News (ISHN) succinctly highlight the risk:

"If the body cannot rid itself of excess heat, it will store it. When this happens, the body’s core temperature rises and the individual becomes sick. As the body temperature approaches 104ºF., the situation becomes life-threatening. At 106ºF, brain death begins."

UCAR predicts "the average annual exposure to extreme heat in the United States during the study period (2041-2070) is expected to be between 10 and 14 billion person-days, compared to an annual average of 2.3 billion person-days between 1971 and 2000." The UCAR study takes a two-pronged approach: it looks not just at warming due to climate change, but also at population trends.

They found that increased exposures to extreme heat due to climate change alone account for only about a third of the projected trend. Another third can be attributed to a combination of increasing temperatures and the growth of populations in those locations where that warming will result in extreme heat days. A final third of the increase in at-risk person days comes from population growth alone -- higher birth rates in and people migrating to areas that have higher heat exposure.

Obviously, the population growth trends may reverse if the extreme heat gets too hot, and that could change the bright colors on the growth charts considerably. But this also comes at an economic cost: areas that become too hot to handle will find their populations dwindling.

Where people can manage the heat waves with air conditioning, economic costs and hospitalizations may be reined in, but the vicious cycle of using energy for air conditioning and increases to the urban heat island effects will contribute to both global and local warming.

Taken altogether, this study should get people thinking about how warming will impact people as well as how businesses and political centers can plan for the future.

Extreme heat exposure up 4 to 6 times by mid-century
Extreme heat kills more people than tornadoes, hurricanes, or any other weather event. How will a 4- to 6-fold increase in extreme heat exposure impact the U.S. population?

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