Is It Hot Enough for You?

Is It Hot Enough for You?
Nicholas Johnson
The Gazette, July 18, 2023, p. A5
I’m about to reveal a new book that could save your life — or at least explain when and why we may all die.

Ever heard of the microbe “Strain 121?” No? I hadn’t either. Turns out it’s able to live in the 212- to 250-degree ocean water from underwater volcanoes.

As you’re probably aware, we Homo sapiens would be thoroughly cooked at those temperatures.

But without heat Earth would be a relatively constant 455 degrees below zero.

Like Goldilocks’ search for the perfect porridge temperature between too hot and too cold, we’ve had — until now — a temperature range that is “just right” for humans.

The mathematical odds of this? Far slimmer than your odds of filling out a perfect NCAA basketball bracket (1 in 120 billion). Especially given our furnace.

The sun is the size of 1.3 million Earths. Its core temperature is 27 million degrees; its surface 10,000 degrees. Every second it sends enough heat 93 million miles, through minus-455-degree space, to equal the heat from three to six Hiroshima-size atomic bombs.

Which brings us to CO2. Without the greenhouse gas levels we used to have our average temperature would be 4 degrees below zero. It’s the CO2’s global warming that made it “just right.”

But we now have two problems moving us from “just right” to “too hot.”

First, the CO2 that’s already there and difficult to remove without a herculean tree-planting project. And second, the increasing amounts of CO2 we’re creating from fossil fuels.

We know about skin cancer and heat stroke from too much sun and drinking water to replace sweat. But there is so much we don’t know. The role of humidity and “wet bulb” thermometers. The impact of heat on the risk of miscarriage, heart attacks, kidney disease, suicides, gun violence and children’s test scores. [Photo: A warning sign in Lake Mead National Recreation Area, February 20, 2022, advising of the danger of extreme heat in the summer months. Source: Wikimedia, Creative Commons.]

That heat has an effect on how cells function, proteins unfold, molecules move, the heart pumps, and organs respond. That 489,000 people worldwide died from extreme heat in 2019, and 850 million live in areas that had all-time record temperatures in 2022.

We built a world for ourselves filled with unarticulated assumptions. During my lifetime I can’t recall hearing or reading anyone’s speculation about, or plan for dealing with top temperatures of 130, 140 or 150 degrees — rather than 100 or, worst case, 120 degrees.

We haven’t built homes, office buildings, highways, railroads, or even wardrobes with excessive, ever-increasing heat in mind — and couldn’t afford to replace them all. We don’t have an electric grid that could support every American’s super-powerful air conditioner running day and night, pumping more heat into our urban heat islands.

So, what’s that new book I promised you? It’s a remarkably creative bit of writing blending facts with, not fiction, but true stories of individuals and families, athletic and experienced, whose planned wonderful day outdoors ended in their death from the heat. It’s Jeff Goodell’s “The Heat Will Kill You First,” published last week.

Nicholas Johnson bought his copy at a local bookstore. You can too. Contact: mailbox@nicholasjohnson.org

SOURCES Strain 121. Caroline Williams, “Extreme survival: Creatures that can take the heat,” New Scientist, Nov. 10, 2010, https://www.newscientist.com/article/mg20827861-600-extreme-survival-creatures-that-can-take-the-heat/ (“The hottest recorded temperature at which life has been able to grow is 121 °C. This record is held by a microbe called simply Strain 121, which normally lives at temperatures of around 100 °C in hydrothermal vents; it barely seemed to notice when it was heated to 121 °C in the lab, in 2003 (Science, vol 301, p 934). Even at 130 °C the bacterium was still hanging in there, but it could not replicate until the temperature dropped.” 100C = 212F; 121C= 250 (249.8)F; 130C = 266F)

“What is a hydrothermal vent? Hydrothermal vents form at locations where seawater meets magma,” National Ocean Service, National Oceanic and Atmospheric Administration, https://oceanservice.noaa.gov/facts/vents.html (“Underwater volcanoes at spreading ridges and convergent plate boundaries produce hot springs known as hydrothermal vents.”)

Coldest place. Joe Phelan, “What is the coldest place in the solar system?” Live Science, April 16, 2022, https://www.livescience.com/coldest-place-in-solar-system (“The baseline temperature of outer space is 2.7 kelvins — minus 454.81 degrees Fahrenheit, or minus 270.45 degrees Celsius — meaning it is barely above absolute zero, the point at which molecular motion stops.”)

Goldilocks. Flora Annie Steel, “Goldilocks and the Three Bears,” 1922, https://americanliterature.com/childrens-stories/goldilocks-and-the-three-bears (“First she tasted the porridge of the Great Big Bear, and that was too hot for her. Next she tasted the porridge of the Middle-sized Bear, but that was too cold for her. And then she went to the porridge of the Little Wee Bear, and tasted it, and that was neither too hot nor too cold, but just right, and she liked it so well that she ate it all up, every bit!”)

Perfect bracket odds. Daniel Wilco, “The absurd odds of a perfect NCAA bracket,” NCAA, March 16, 2023, https://www.ncaa.com/webview/news%3Abasketball-men%3Abracketiq%3A2023-03-16%3Aperfect-ncaa-bracket-absurd-odds-march-madness-dream (“Here's the TL/DR version of the odds of a perfect NCAA bracket: 1 in 9,223,372,036,854,775,808 (if you just guess or flip a coin) 1 in 120.2 billion (if you know a little something about basketball)”)

The Sun. General: “Our Sun,” Solar System Exploration; Our Galactic Neighborhood, NASA, July 12, 2023, https://solarsystem.nasa.gov/solar-system/sun/in-depth/ (“The Sun is a 4.5 billion-year-old yellow dwarf star – a hot glowing ball of hydrogen and helium – at the center of our solar system. It’s about 93 million miles (150 million kilometers) from Earth and it’s our solar system’s only star. Without the Sun’s energy, life as we know it could not exist on our home planet. . . . [Size of sun: “Many stars are much larger – but the Sun is far more massive than our home planet: it would take more than 330,000 Earths to match the mass of the Sun, and it would take 1.3 million Earths to fill the Sun's volume.”]

Heat from atomic bombs. Damian Carrington, “Global warming of oceans equivalent to an atomic bomb per second; Seas absorb 90% of climate change’s energy as new research reveals vast heating over past 150 years,” The Guardian, Jan. 7, 2019, https://www.theguardian.com/environment/2019/jan/07/global-warming-of-oceans-equivalent-to-an-atomic-bomb-per-second (“A Guardian calculation found the average heating across that 150-year period was equivalent to about 1.5 Hiroshima-size atomic bombs per second. But the heating has accelerated over that time as carbon emissions have risen, and was now the equivalent of between three and six atomic bombs per second. . . . The total heat taken up by the oceans over the past 150 years was about 1,000 times the annual energy use of the entire global population. The research has been published in the journal Proceedings of the National Academy of Sciences and combined measurements of the surface temperature of the ocean since 1871 with computer models of ocean circulation.”)

Without greenhouse gases. “The Greenhouse Effect,” British Geological Survey (BGS), undated, https://www.bgs.ac.uk/discovering-geology/climate-change/how-does-the-greenhouse-effect-work/ (“‘Greenhouse gases’ are crucial to keeping our planet at a suitable temperature for life. Without the natural greenhouse effect, the heat emitted by the Earth would simply pass outwards from the Earth’s surface into space and the Earth would have an average temperature of about -20°C.” = -4F . . . Footnote 1. “1. Enhanced Greenhouse effect 'Greenhouse gases' are actually crucial to keeping our planet at a habitable temperature, without them the Earth would be about minus 17 degrees! Anthropogenic or human release of carbon dioxide is what is contributing to an additional or enhanced greenhouse effect.” . . . The contribution that a greenhouse gas makes to the greenhouse effect depends on how much heat it absorbs, how much it re-radiates and how much of it is in the atmosphere. In descending order, the gases that contribute most to the Earth’s greenhouse effect are: water vapour (H2O) carbon dioxide (CO2) nitrous oxide(N2O) methane (CH4) ozone (O3) In terms of the amount of heat these gases can absorb and re-radiate (known as their global warming potential or GWP), CH4 is 23 times more effective and N2O is 296 times more effective than CO2. However, there is much more CO2 in the Earth’s atmosphere than there is CH4 or N2O. Not all the greenhouse gas that we emit to the atmosphere remains there indefinitely. For example, the amount of CO2 in the atmosphere and the amount of CO2 dissolved in surface waters of the oceans stay in equilibrium, because the air and water mix well at the sea surface. When we add more CO2 to the atmosphere, a proportion of it dissolves into the oceans.”)

CO2 and trees. Michael Taylor, “Global warming fast shrinking rainforest role as climate protector,” Reuters, March 4, 2020, https://www.reuters.com/article/us-global-forests-climate-change/global-warming-fast-shrinking-rainforest-role-as-climate-protector-idUSKBN20R2HD (“But the 30-year study, led by the University of Leeds and involving almost 100 institutions, showed that the intake of carbon by “intact tropical forests” peaked in the 1990s and had dropped by a third by the 2010s.

Intact forests are large areas of continuous forest with no signs of intensive human activity like agriculture or logging. They form part of the world’s roughly 5.5 billion hectares of forest.

Trees suck carbon dioxide from the air, the main greenhouse gas heating up the Earth’s climate, and store carbon, which they release when they are cut down and are burned, or rot.

Tropical forests are huge reservoirs of carbon, storing 250 billion tonnes in their trees alone - an amount equivalent to 90 years of global fossil-fuel emissions at current levels.”)

Mark Tutton, “Restoring forests could capture two-thirds of the carbon humans have added to the atmosphere,” CNN, July 5, 2019, https://www.cnn.com/2019/07/04/world/forests-capture-two-thirds-of-carbon-emissions-scn-intl/index.html (“Restoring the world’s lost forests could remove two thirds of all the planet-warming carbon that is in the atmosphere because of human activity, according to a new study.

Since the industrial revolution, humans have added around 300 billion tons of extra carbon to the atmosphere – mainly through burning fossil fuels – which is heating the planet to dangerous levels. But trees naturally remove carbon from the atmosphere, storing it above and below ground.

A new study, carried out by researchers at Swiss university ETH Zurich and published Thursday in the journal Science, has calculated that restoring degraded forests all over the world could capture about 205 billion tons of carbon in total. Global carbon emissions are currently around 10 billion tons per year.”)

Sun and skin cancer. “How does the sun cause cancer?” Worldwide Cancer Research, March 1, 2022, https://worldwidecancerresearch.org/news-opinion/2022/march/how-does-the-sun-cause-skin-cancer/ (“Over 80% of skin cancers are caused by overexposure to UV radiation. This includes UV rays from the sun, but also from sunbeds and tanning lamps. UV radiation damages DNA in your skin cells, which can accumulate over time and increase the risk of genetic mutations that cause skin cancer. The more often you get burnt, the more damage is done and the higher the risk of skin cancer. It’s also important to know that you don’t necessarily need to get a sunburn for UV rays to damage your cells.”)

Paragraph beginning, “Most of us know about skin cancer . . .” Jeff Goodell, “The Heat Will Kill You First,” 2023, pp. 18-20

Heat and the human body. (almost two pages of quotes for this one entry) Ruby Mellen and William Neff, “What extreme heat does to the human body; Climate change is making parts of the world too hot and humid to survive,” Washington Post, July 28, 2021, https://www.washingtonpost.com/world/interactive/2021/climate-change-humidity/ (“Deadly heat waves have swept the globe and will continue to because of climate change. - The trends are prompting doomsday questions: Will parts of the world soon become too hot to live in? How will we survive?

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.

At a certain threshold of heat and humidity, “it’s no longer possible to be able to sweat fast enough to prevent overheating,” said Radley Horton, a professor at Columbia University’s Lamont-Doherty Earth Observatory.

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.

As the sun heats up the air, the ground, objects and people, the human body will react in an effort to cool itself.

The skin sweats. Evaporation of this water cools the body — as long as the surrounding humidity levels allow the evaporation to take place.

If the hot air is too humid, that heat exchange is blocked and the body loses its primary means of cooling 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.

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.

As your body works to cool down, the heart works harder in an effort to pump blood up just below the surface of the skin, where it can get cooler.

The kidneys work harder to conserve your body’s water.

When your body temperature gets too high, it will ultimately cause your body’s proteins to break down, its enzymes to stop regulating your organs’ functions and your organs to start shutting down.

This is a heat stroke: Your body essentially cooks to the point where you have multi-organ failure.

“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.”)

Casey Crownhart, “How hot is too hot for the human body? Climate change is bringing extreme heat and testing the limits of what people can tolerate,” MIT Technology Review, July 10, 2021, https://www.technologyreview.com/2021/07/10/1028172/climate-change-human-body-extreme-heat-survival/ (“For a study published in Nature Climate Change in 2017, Mora and his team analyzed hundreds of extreme heat events around the world to determine what combinations of heat and humidity were most likely to be deadly, and where those conditions were likely to occur in the future.

They found that while today around 30% of the world’s population is exposed to a deadly combination of heat and humidity for at least 20 days each year, that percentage will increase to nearly half by 2100, even with the most drastic reductions in greenhouse-gas emissions.

Other researchers have found that climate change is making extreme heat waves up to hundreds of times more likely and causing over a third of heat-related deaths. We’re changing our planet—what are the limits of what we can endure? . . .

When your core temperature gets too hot, everything from organs to enzymes can shut down. Extreme heat can lead to major kidney and heart problems, and even brain damage, says Liz Hanna, a former public health researcher at the Australian National University, who studies extreme heat.

Your body works to maintain its core temperature in hot environments mostly by using one powerful tool: sweat. The sweat you produce evaporates into the air, sucking heat from your skin and cooling you down. . . .

Wet-bulb temperature can estimate what your skin temperature would be if you were constantly sweating, so it’s often used to approximate how people would fare in extreme heat.

A wet-bulb temperature of 35 °C, or around 95 °F, is pretty much the absolute limit of human tolerance, says Zach Schlader, a physiologist at Indiana University Bloomington. Above that, your body won’t be able to lose heat to the environment efficiently enough to maintain its core temperature. That doesn’t mean the heat will kill you right away, but if you can’t cool down quickly, brain and organ damage will start.”)

“Heat and Health,” World Health Organization, June 1, 2018, https://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health

Katherine Gianni & Molly O’Brian Gluck, “How Does Heat Exposure Affect The Body and Mind?; Know the heat-related illness risks for physical, mental health and how to stay safe when temperatures rise,” (Q&A with “Gregory Wellenius, Boston University professor of environmental health and director of BU’s Program on Climate and Health”) The Brink, Boston University, July 6, 2021, https://www.bu.edu/articles/2021/how-does-heat-exposure-affect-the-body-and-mind/ (“Heat doesn’t just impact the body; it also impacts the mind. . . . “Hot days can lead people to suffer from dehydration, heat exhaustion, and in extreme cases, heat stroke. But hot days are also associated with higher risk of a number of other conditions that are not typically thought to be “heat-related,” such as [kidney] problems, skin infections, and preterm birth among pregnant women. . . . moderately hot days can place vulnerable individuals at higher risk.” “a recent study in New York found that hot days were associated with higher risk of emergency room visits for substance abuse, mood and anxiety disorders, schizophrenia, and dementia. Other studies show that hot weather is linked to lower performance on standardized tests, higher risk of judgment errors, and higher risks of occupational injuries.”)

Sarah Griffiths, “Will Texas become too hot for humans? Texas is in the grip of a relentless heatwave – but how much hotter could summers get in years to come?” BBC Future, June 30, 2023, https://www.bbc.com/future/article/20230630-will-texas-become-too-hot-for-humans (“Extreme heat is currently the deadliest natural hazard in the US, with young children and adults over the age of 65 among the most vulnerable to heat-related illness and death. Analysis by The Texas Tribune found more than 275 people in Texas died from heat-related illness in 2022, which was a two-decade high, and this year's heatwave appears to be worse.

Young children, the elderly, the sick, and the poor who cannot afford technology including air-conditioning to help keep them cool are particularly vulnerable to the effects of extreme heat. High air temperatures can cause heat stroke, dehydration and affect people's cardiovascular and nervous systems. . . .

a "wet-bulb" temperature of 95F (35C) at 100% humidity, or 115F at 50% humidity is probably as hot as most humans can maintain a healthy core body temperature by sweating. Above that "critical environmental limit" our body temperature rises continuously and the risk of heat-related illnesses such as heat stroke increases. . . .

And even when they aren't life-threatening, hotter temperatures can impair cognition, motor control and affect our ability to perform everyday tasks. . . . It's well-established that warmer weather can make us more aggressive, increasing rates of violent crime and the probability of social unrest. . . . "Over the next 50 years, millions of Americans will be caught up in this churn of displacement, forced inland and northward in what will be the largest migration in our country's history," says author Jake Bittle, whose book The Great Displacement, tell stories of people forced to leave their homes due to extreme weather events.”)

Deaths from heat. Jeff Goodell, “The Heat Will Kill You First,” 2023, p. 18 (“A study in the Lancet . . . estimated that 489,000 people worldwide died from extreme heat in 2019.”)

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