Guest essay by Eric Worrall

People who work in bakeries, factories or mines deal with 130F / 54C+ on a regular basis. But for climate scientists working in comfortable offices, anything above 122F / 50C seems to represent some kind of death line.

Kuwait is fast becoming unlivable as global warming takes its toll

Temperature records are being smashed all over the world, but Kuwait – one of the hottest countries on the planet – breached 50 degrees Celsius in June, weeks ahead of its usual peak weather.

Fiona MacDonaldJan 20, 2022 – 9.00am

Trying to catch a bus at the Maliya station in Kuwait City can be unbearable in the summer. About two-thirds of the city’s buses pass through the hub, and schedules are unreliable.

Fumes from bumper-to-bumper traffic fill the air. Small shelters offer refuge to a handful of people, if they squeeze. Dozens end up standing in the sun, sometimes using umbrellas to shield themselves.

Global warming is smashing temperature records all over the world, but Kuwait – one of the hottest countries on the planet – is fast becoming unlivable.

In 2016, thermometers hit 54C, the highest reading on Earth in the last 76 years. Last year, for the first time, they breached 50 degrees Celsius in June, weeks ahead of usual peak weather. Parts of Kuwait could get as much as 4.5C hotter from 2071 to 2100 compared with the historical average, according to the Environment Public Authority, making large areas of the country uninhabitable.

For wildlife, it almost is. Dead birds appear on rooftops in the brutal summer months, unable to find shade or water. Vets are inundated with stray cats, brought in by people who’ve found them near death from heat exhaustion and dehydration. Even wild foxes are abandoning a desert that no longer blooms after the rains for what small patches of green remain in the city, where they’re treated as pests.

“This is why we are seeing less and less wildlife in Kuwait, it’s because most of them aren’t making it through the seasons,” said Tamara Qabazard, a Kuwaiti zoo and wildlife veterinarian. “Last year, we had three to four days at the end of July that were incredibly humid and very hot, and it was hard to even walk outside your house, and there was no wind. A lot of the animals started having respiratory problems.”

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Read More: https://www.afr.com/policy/energy-and-climate/kuwait-is-fast-becoming-unlivable-as-global-warming-taks-its-toll-20220119-p59pha

Humans are well adapted to working in extreme heat.

I have personal experience of working in extreme heat. One of my first jobs was working in a chemical factory in Melbourne, Australia.

Melbourne has scorching hot Summers. The factory floor temperature regularly exceeded 120F in Summer. One week the outside temperature hit 110F every day. There was a factory floor thermometer which hit 130F by 10am every day that week.

The factory floor was wet and steamy like a tropical jungle, because the chemical production line released a tremendous amount of water vapour. The factory also contained lots of ancient steam heated hydraulic presses, fed by leaky pipes, which added to moisture. Conditions were so wet, droplets of water were continuously condensing on some of the machines, even when the shop floor temperature hit 130F.

I’m not sure what the web bulb temperature was on the shop floor that week, but it must have been impressive. Management were very concerned during the heatwave, they made us drink a plastic cup of electrolyte fluid every 5 minutes. There was a well equipped in-house laboratory attached to the factory which performed regular quality assurance on the products, so I think management knew exactly what the wet bulb temperature was on the factory floor. But if they knew they weren’t telling.

How could myself and my fellow workers possibly function in a web bulb temperature which was almost certainly above 35C? The following offers some insights.

Simplicity lacks robustness when projecting heat-health outcomes in a changing climate

Jennifer K. Vanos,¹Jane W. Baldwin,²Ollie Jay,^3,4 and  Kristie L. Ebi⁵Author informationArticle notesCopyright and License informationDisclaimer

Extreme heat adversely affects human health, productivity, and well-being, with more frequent and intense heatwaves projected to increase exposures. However, current risk projections oversimplify critical inter-individual factors of human thermoregulation, resulting in unreliable and unrealistic estimates of future adverse health outcomes.

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Capturing these complexities allows researchers to understand the level of heat strain that eventuates from heat stress, and by extension heat-related health outcomes. These complexities are currently neglected within common heat-related health projections. For example, the most commonly used metric for projecting future heat-related mortality is the wet-bulb temperature (T_w) threshold of 35 °C (e.g.¹⁰,), which is based on a thermodynamic limit to heat exchange whereby the human body becomes an adiabatic system (Table 1). The conservative assumption that this value must be reached to cause widespread death is only valid under a specific set of conditions, i.e., the person is completely sedentary, unclothed, maximally heat acclimatized, and an average-sized adult free from any thermoregulatory impairments. These assumptions are implausible in the real-world, and severe illness and death can occur at much lower heat stress levels when considering realistic metabolic heat loads, clothing, population demographics, and health status. In essence, using this T_w threshold without questioning such implicit assumptions could result in substantial underestimation of the future range and potential severity in heat-related outcomes. Conversely, the single threshold can also overestimate risk as humans are known to live in harsh climates through buffering the effects of climate extremes using adaptive innovations. Often these innovations involve technological, infrastructural, and behavioral adaptations that support minimizing extreme exposures and/or the amount of time an individual is exposed to the given extreme¹¹.

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The general applicability, and thus usability, of projections are questionable when they are based on a single ambient threshold at which mortality is presumed to occur applied to an inanimate unclothed human (e.g., T_w of 35 °C) versus a range of outcomes with underlying uncertainties. Moreover, without considering the temporal duration of exposure, space, activity, clothing, behavior, and most of all, individual physiology, the mismatch between complex climate models and over-simplified human models fails to provide useful information for decision-makers. Embedding more sophisticated human heat stress models into climate projections would provide relevant health projections across a more realistic and therefore diverse population than an assumed idealized individual.

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Read more: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7695704/

My point is, if you are used to extreme conditions, like people who work in hot factories, or people who live in very hot places like Kuwait, those extreme conditions are normal and bearable. I’m confident we regularly exceeded 35C wet bulb on the hottest days for most of our 8 hour work day, given the extreme temperature and the beads of water condensing on the machines – but we were fine.

The most interesting part of the experience, when the work shift ended at 3pm, and I walked out into the 110F outside temperature covered in sweat, I sometimes started shivering. For a few minutes I felt freezing cold on a 110F day, as my body re-adjusted back to cooler outside conditions.

If I walked into that factory today, without adapting to the heat, I would find it very difficult to function. But if you build up to it, work for months in slightly cooler temperatures as outside temperatures build up to peak Summer, most people’s bodies can adapt.

Scientists claim that old people have more trouble adapting to heat. But a lot of the people working in that factory were old. From memory the shop floor people I worked with were half a dozen ageing chain smoking East Europeans, a pregnant Pacific islander and a couple of Asians. Most of them had worked there for years and some were now close to retirement. None of them had any problem coping with the heat.

So why do climate scientists assume 35C web bulb is a hard limit?

I suspect the reason is studying the true limits of human endurance is kindof difficult. It would be highly unethical to put people into a test oven and crank up the heat and humidity until they pass our or die. In any case test subjects would need weeks of adaptation to cope with the kind of temperature and humidity I’m describing, to produce a representative result.

Studying people in Kuwait is also an issue. Ever notice those picturesque towers on top of buildings in the middle east? Medieval air conditioning (see the picture at the top of the page). Even the houses of poor people often had small wooden wind catchers before the advent of modern air conditioning. People in hot climates are not stupid, they don’t prance around in the midday sun testing their personal physiological limits unless they have to – even though they could if they had to.

Scientists could try to find workplaces where people already regularly endure extreme conditions beyond 35C web bulb limits, but getting a company manager to admit such extreme workplace conditions exist might be an issue. Workplace regulations are written by people who believe in hard wet bulb limits, so it seems likely the factory where I worked was seriously breaching health and safety laws by continuing to operate during a heatwave, even if none of us actually suffered any harm.

My factory job was by no means unique – talking to friends, there are plenty of factories and other workplaces which quietly ignore the alleged limits to human survival.