A UN report published this week showed that global temperature increases for the past 30 years have been well above the rate of increase scientists would expect without human-caused climate change.
Now researchers predict that heat extremes in the U.S. are likely to get worse over the next half-century.
“We see it as very much a climate-change-related risk,” said Andrew Weaver, a research fellow at the University of Victoria’s Centre for Climate Change and Sustainable Development in British Columbia, Canada.
Heat waves with “high confidence” such as heat waves in Southern California, Texas and Florida, are “likely to continue in all climate scenarios over the next 50 years,” according to the report, which was released this week by the UN’s Intergovernmental Panel on Climate Change.
It’s the first time the panel has used that term, and this warming trend is being driven by emissions of carbon dioxide, which has been increasing since the Industrial Revolution, according to the report.
In its 22nd report, the IPCC predicted temperature rises at a rate of 1.5 to 3.5 degrees Fahrenheit above pre-industrial times.
Scientists added words such as “very likely” to their calculations, and the report described those warm days as “dangerous” because they will increase the chances of heat-related illnesses like asthma, heat stroke and heat exhaustion.
Hot days with high confidence in the years 2031 to 2099. Source: IPCC 2019 Climate Change Report
The report didn’t look at cities in the U.S. and make the link explicitly, but it could make scientists think more seriously about heat stress or overall vulnerability to such events, according to Michael Mann, director of the Earth System Science Center at Penn State University.
Even an increase of 6 degrees to 9 degrees Fahrenheit by the end of the century could prompt heat-related illnesses in most of the country, the report noted.
Heat waves caused more than 1 million deaths worldwide in 2016, and while people in the U.S. tend to be less resilient to heat than people living in warm, temperate regions of the world, the risk of health damage from extreme heat is greater here than elsewhere, according to a report from the National Oceanic and Atmospheric Administration.
In the U.S., the greatest effects of heat waves came on days with high temperatures exceeding 100 degrees, with 20 million heat-related illnesses and 106 deaths reported in 2016, according to a report from the National Weather Service.
As the heat wave was making its run this week in the Northeast and Midwest, the National Weather Service announced a heat advisory for metropolitan Detroit and Pittsburgh that is in effect through Sunday morning.
As temperatures once again soar, it might be useful to remember that many of the buildings in the Washington area were not designed to withstand temperatures over 100 degrees. Washington has averaged an annual average temperature of 63.6 degrees this year and has tied or broken records in 16 of the 16 weeks to date, according to the National Weather Service.
In October, the National Center for Atmospheric Research in Boulder, Colorado, published a study that showed superheated city air contains 10 times more airborne carbon dioxide than the air in a bird or cat, The Washington Post reported.
“In many buildings in the U.S., that was the heat load,” said Dr. Thomas Karl, the director of the National Centers for Environmental Information.