July 28, 2021
image above: convergence.unc.edu
WN: The concluding quote is ominous:
“As humans, we have learned to adapt,” Tereza Cavazos [a senior researcher in the department of physical oceanography at the Ensenada Center for Scientific Research and Higher Education], said. “The problem is the cost. Some will not survive.”
This article is largely news to me . . .
When it comes to heat, the human body is remarkably resilient — it’s the humidity that makes it harder to cool down. And humidity, driven in part by climate change, is increasing.
A measurement of the combination of heat and humidity is called a “wet-bulb temperature,” which is determined by wrapping a completely wet wick around the bulb of a thermometer. Scientists are using this metric to figure out which regions of the world may become too dangerous for humans.
A term we rarely hear about, the wet-bulb temperature reflects not only heat, but also how much water is in the air. The higher that number is, the harder it is for sweat to evaporate and for bodies to cool down.
Scientists have found that Mexico and Central America, the Persian Gulf, India, Pakistan and Southeast Asia are all careening toward this threshold before the end of the century.
“Humid heat risks are grossly underestimated today and will increase dramatically in the future,” Horton said. “As locations around the world experience previously rare or unprecedented extremes with increasing frequency, we run the risk that our previous messaging about extreme heat risk — already woefully inadequate — will fall further short of the mark.”
To better understand why these places are becoming too hot and humid for humans to endure, you have to first understand how the body cools itself.
The wet-bulb temperature that marks the upper limit of what the human body can handle is 95 degrees Fahrenheit (35 Celsius). But any temperatures above 86 degrees Fahrenheit (30 Celsius) can be dangerous and deadly. Horton and other scientists noted in a 2020 paper that these temperatures are occurring with increasing frequency in parts of the world. To put things in perspective, the highest wet-bulb temperature ever recorded in the Washington region, known for its muggy, unbearable summers, was 87.2 degrees (30.7 Celsius).
“Extreme humid heat overall has more than doubled in frequency since 1979,” the study’s authors wrote.
These conditions are reaching that deadly threshold in places like South Asia and the Middle East and could regularly cross it by 2075, scientists say.
“Just increasing 1 or 2 degrees Celsius can be the tipping point for changing the impact,” Cavazos said.
The blistering heat is resulting in difficult living conditions, especially for communities that lack resources to provide relief.
Why some will survive while others die
Even below these thresholds, cooling down is hard work on the body. The efforts to fight the effects of heat puts pressure on your heart and kidneys. With extreme heat, people’s organs can start to fail. If you have preexisting conditions, it’s even more likely.
the extreme conditions.
“It’s very clear during a heat wave, more people do die of heat stroke,” said Zachary Schlader, an associate professor at Indiana University Bloomington who focuses on thermal stress and the human body. But even more die of heart-related conditions. “The body responds [to heat] in such a way it could make the organ vulnerable.”
Protecting yourself from such stress is inextricably tied to socioeconomic status and resources.
“The poorest people are the most vulnerable, and they are already suffering,” Cavazos said, noting that Sonora depends on farming, meaning a lot of people have to engage in physical labor in the dangerous heat.
In regions like the Persian Gulf, extreme heat is the new normal: Qatar has adapted so extensively to the blistering climate that it air-conditions the outdoors. But not everyone has access to outdoor air conditioning, including those building the facilities that have them. When the wealthy country began construction on venues to host the 2022 World Cup, it faced an uproar over its treatment of workers building the stadiums.
Please click on: Wet-Bulb Temperature