The Hottest Temperature Humans Can Survive

🌡️ The Hottest Temperature Humans Can Survive

As climate change continues to warm the Earth, blistering hot days are becoming more common. Around 70% of the global workforce, equating to 2.4 billion people, are now at high risk of extreme heat. One team of physiologists is using state-of-the-art climate chambers to investigate conditions under which heat threatens life, and how people can stay cool. In the chambers, temperatures can range from 5C to 55C, with windspeed controls and sunlight simulators, as well as the ability to fine-tune humidity - a key variable that influences heat’s effects on the body. Scientists used the climate chambers to see at what wet bulb temperature (WBT) a young, healthy person would die after six hours. In previous studies in 2010, models predicted a WBT of 35C as the limit of human survival, where the body’s core temperature would rise uncontrollably. A more recent 2021 study suggested a WBT limit of 31C. The research teams are now adding physiology such as sweating capacity, sun vs shade, and during exercise to the modeling to obtain more accurate results.

Carissa Wong, nature

🌊 Atlantic Niña Possible This Year

Scientists have been observing the Pacific Ocean change from El Niño’s warmer-than-average conditions a few months ago to cooler-than-average La Niña conditions by late summer or early fall. However, something similar may be taking shape in the Atlantic Ocean this summer. The North Atlantic has been extremely warm so far this year, but as of the beginning of June, the Atlantic has been 0.5-1.0C colder than average for this time of year. If these cold conditions persist through the end of August, a phenomenon known as Atlantic Niña may be declared. Atlantic Niña is the cold phase of the Atlantic zonal mode, while Atlantic Niño is the warm phase. Typically, 3-month averaged sea surface temperature anomalies in the eastern equatorial Atlantic have to exceed +/- 0.5C for at least two overlapping seasons to qualify as an Atlantic Niño or Niña. If Atlantic Niña does develop, the cooler water could have a dampening effect on hurricane activity as the season progresses. This could be an interesting development as numerous entities predicted an extremely active hurricane season.

Franz Philip Tuchen, Climate.gov

📖 16,000 Years of Climate History Revealed in Andes

A recent study exploring ancient temperature and rainfall patterns in the tropical Andes of South America has revealed how 16,000 years of climate history was driven by CO2 levels and ocean currents from global climate events. Recent evidence suggests that temperatures near the Andes are more influence by the Southern Hemisphere. The tropical Andean temperatures were similar to Antarctic temperatures, which are mainly controlled by CO2 concentrations. Their findings show that Andean temperatures rose when CO2 increased, and remained relatively stable when CO2 levels remained relatively stable. The study also highlighted the role of ocean currents and how when the northward current is strengthened, warm water is transported northward and cool sea surface temperatures remained in the south, extending to the tropical Andes.

Brown University, Phys.org