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+--- Thread: Article 100% humidity heatwaves are spreading across the Earth. A deadly problem for us (/thread-16534.html)
100% humidity heatwaves are spreading across the Earth. A deadly problem for us - C C - Sep 21, 2024
https://www.sciencefocus.com/planet-earth/100-humidity-heatwaves-are-spreading-across-the-earth-thats-a-deadly-problem-for-us
EXCERPT: . . . For a 2°C (3.6°F) global average temperature rise, which – given inaction on emissions reductions – is almost certain, dangerous humid heatwaves will become prevalent in many parts of the world.
Most at risk will be those living in northern India, Pakistan, Bangladesh, the Arabian Gulf, the Sahel region of Africa and East Asia. Because of the so-called ‘heat island effect’, whereby urban centres dominated by concrete and tarmac are hotter than their surroundings, those in cities will be most at risk.
WBTs approaching 31°C (87.8°F), at which working outdoors would be all but impossible, are forecast to occur in excess of 200 hours a year in Aden (Yemen), more than 150 hours in Lahore (Pakistan), and 30–40 hours in the Indian cities of Delhi and Kolkata.
A global temperature rise of 3°C (5.4°F) would see an extension of these conditions, which would begin to be encountered in Tokyo (Japan), Lagos (Nigeria), Shenzhen (China), Chicago and New York (USA).
Cities are invariably hotter than the countryside, but this is not to say that rural regions won’t suffer. A 2018 study highlighted a particular threat to the North China Plain: the country’s breadbasket, criss-crossed by a dense network of irrigation courses.
Not only does all this water push up humidity levels, it's predicted to raise the temperature across the region by 0.5°C (0.9°F). While I suspect there are other candidates, the authors of the study warn that the region faces “the greatest risk to human life from rising temperatures of any location on Earth.”
Bearing in mind that this is one of the most densely populated parts of the planet – home to more than 400 million people, mostly farmers – this is not a surprise.
The increased risk arising from extreme heat and humidity is compounded here due to the majority of people being involved in physical outdoor work, and a lower availability of air conditioning than in cities. The study predicts that heatwaves in which the WBT exceeds 35°C (95°F) will occur repeatedly from about 2070, if we do nothing to curb emissions.
Individual events will, of course, happen much sooner, along with an increasing frequency of WBTs of 31°C (87.8°F), which, at the very least, will bring working outside to a grinding halt. It’s even questionable whether places like the North China Plain will continue to be habitable.
Certainly, the heat-related disaster that hit the 2024 Hajj could pale into insignificance compared to future death tolls from humid heatwaves in this part of China.
Looking to the future
This brings me to the broader outlook for our world as global temperatures continue to surge. Agriculture across the planet is already under pressure from super-charged weather, notably drought, floods, hail and wildfires, leading to reduced harvests of coffee, cocoa, olives and staples like rice, maize and wheat in recent years.
Even in temperate regions like the UK, yields of wheat, oats, barley and oilseed rape are forecast to be down collectively by almost 18 per cent this year. In tropical regions, on top of the drops in yields, farmers will have to contend with extreme conditions that will make it difficult, if not impossible, to tend crops.
Productivity will inevitably take a massive hit. In the decades to come, working outside during the summer in places as far apart as southern Europe, North America, South and South East Asia, and large parts of Africa, is going to be at best excessively unpleasant and, at worst, fatal.
This won’t just apply to agriculture either. Extreme heat and humidity will severely impact increasingly other sectors... (MORE - missing details)