HealthDay Reporter
DUNDAY, March 8, 2021 (HealthDay News) – Global warming could limit targets proposed in Paris Agreement to keep tropical regions from reaching temperatures beyond human suffering, new project study .
Researchers predict that if countries are able to warm at 1.5 degrees Celsius above pre-industrial levels, the tropics will be subdued by temperatures that exceed the “survival rate.” life in the hottest latitudes in the world could be impossible if these controls are not met.
The study focused on a measurement called wet bulb temperature, which reports heat and humidity, and is similar to what weather observers call a heat index.
“The general opinion is, the body just doesn’t respond to temperature, it responds to humidity,” said Kristina Dahl, a climate scientist who was not involved in the study.
The body cools primarily through taking a shower and wiping sweat from the skin, Dahl explained. At a certain temperature of humidity, she said, it becomes “thermodynamically difficult” for that to happen.
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Scientists believe that a wet bulb temperature of 35 degrees C is the highest level of human tolerance. It resembles a heat index of 160 degrees Fahrenheit.
People will be different in how much heat they can withstand. But at a wet-bulb temperature of 35 degrees C, anyone living outside would be in trouble.
The body normally maintains a stable internal temperature of 37 degrees C (98.6 degrees F). Skin temperature needs to be slightly lower, to allow heart heat to flow to the skin. If not, a person’s internal temperature could rise rapidly, explained Yi Zhang, the lead researcher on the new study.
“High heart temperatures are dangerous or even fatal,” said Zhang, a graduate student in atmospheric and oceanic sciences at Princeton University in New Jersey.
For their study, Zhang and her colleagues made predictions on how global warming might affect wet bulb temperatures in the tropics (between 20 degrees north and south of the equator). That includes the Amazon rainforest, a large part of Africa, the Indian peninsula and parts of Southeast Asia.
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The researchers started with the theory that very simple atmospheric dynamics control local wet bulb temperatures throughout that tropical region. They then used decades’ worth of weather station data to prove that this was the case.
From there, they were able to project that if global warming is limited to 1.5 degrees Celsius, that will stop “most tropics” from reaching the temperature of an incandescent wet bulb. tolerant.
The findings were published March 8 in the journal Geology of nature.
Under the Paris Agreement, an international consensus on climate change, the target is to limit global warming to a “significantly lower” 2 degrees Celsius, and approximately 1.5 degrees, compared to pre-industrial levels.
These latest projections confirm that importance, said Dahl, a senior climate scientist with the Nonprofit Union of Concerned Scientists.
The decisions translate a policy target into a potential world impact, Dahl said.
But turning the temperature of an intolerable wet bulb does not mean that the planet is out of the woods. Human health can certainly suffer under not so much heat, she said.
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Regular heat waves cause fatal heat illness. Warming also contributes to air pollution, which can exacerbate harmful health conditions such as heart and lung disease, Dahl said.
A group of medical organizations called the Medical Association Consortium on Climate and Health has highlighted a range of health effects associated with global warming. It can feed on insects such as Lyme and Zika disease, for example, or contaminate food and water by causing rising sea levels, heavy rainfall and flooding.
Zhang said more research is needed to fully understand the health effects of wet bulb temperatures below the “survival rate” of 35 degrees C. She also noted that the study only looked at countries between specific latitudes, and that the co -decisions to apply to other departments.
What is needed to stop global warming? The short answer, according to Dahl, is less reliance on fossil fuels (oil, coal and natural gas) and greater use of cleaner energy sources such as supply and wind.
Man-made emissions – particularly carbon dioxide, as well as nitrous oxide and methane – have been blamed for rising global temperatures since the 1950s. In the United States, most of these emissions come from burning fossil fuels for energy use, according to the U.S. Energy Information Administration.
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Find out more
The World Health Organization has more on climate change and health.
SOURCE: Yi Zhang, graduate student, atmospheric and oceanic sciences, Princeton University, Princeton, NJ; Kristina Dahl, PhD, senior climate scientist, climate and energy program, Union of Critical Scientists, Cambridge, Mass .; Geology of nature, March 8, 2021, online