The Climate in Emergency

A weekly blog on science, news, and ideas related to climate change


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How Heat Hurts

I got heat exhaustion today. Unfortunately, this is not an unusual occurrence for me–I seem to be unusually susceptible. I don’t know why. Heat exhaustion is one of several types of heat-related illnesses. It is not, in itself, normally dangerous, but can progress to heat stroke, which can kill you.

Heat is a matter of weather—but it is also a matter of climate. Obviously, global warming means more hot days, but the increase doesn’t work quite the way intuition says it should. Intuitively, an average warming of, say, one degree Fahrenheit, should add one degree on to typical daily temps. So if your normal summer day was 90 degrees, now it’s 91 degrees. Not a big difference. But that’s not how it works.

As I have addressed before, a small increase in average temperature results in a large increase in the frequency of heat waves. This is because there is a well-established link between rarity and severity across many different types of variation, from body height to intelligence to air temperature. A slight increase above average (a few degrees, a few inches….) translates into a dramatic decrease in frequency of occurrence. How often do you see people who are six feet tall? Now often do you see people who are seven feet tall? The difference seems larger than what a mere twelve inches would imply.

A hotter normal means that severe heat waves that used to be very rare become common-place, while the human vulnerability to heat injury remains roughly the same.

My illness today is not particularly a climate change story–it was not one of those events that make it obvious normal has changed. Hot days in mid-June are not new for Maryland. But the experience did inspire me to do some reading about how heat stroke actually works—more people die from heat than from all other natural disasters combined. I decided I wanted to know more about what happens in the body when it gets hot.

Please note that I’m skipping over issues like how to recognize and treat heat-related problems. For that information, look up a public health website maintained by a reputable medical institution (anything else, and you’ll likely be reading content written by free-lance writers who don’t know anything more about medicine than you do).

Definitions

When I received emergency medical training years ago, I learned that heat exhaustion is essentially a form of aggravated dehydration—the body is not hotter than it should be, but keeping cool is taking too much effort, including loss of so much water through sweat that blood volume drops. The symptoms are mostly the body’s attempt to compensate for lost blood volume in order to keep adequate blood flow to the brain. Heat injury and then heat stroke, in contrast, result when the body’s cooling system fails (sometimes because dehydration has become critical and the sweat response shuts off—when a person who should be sweating isn’t, that’s a very bad sign) and body temperature rises uncontrollably. Doctors then have hours or even minutes to act before the patient literally cooks to death.

Like most simple explanations, this one is not quite right. For example, brain damage in heat stroke is not caused by the brain tissue heating up, as I’d been led to believe–instead, excessive heat causes the blood/brain barrier to become leaky, allowing substances into the brain that should not be there, and that causes damage. Heat stroke, though triggered by heat (either through passive exposure to high temperature or to excessive exercise in hot weather or under too much clothing), actual injury—and often death—is not the direct result of the body cooking. After all, cooking occurs at specific temperatures (that’s why recipes work), but the temperature at which heat injury occurs is variable. There are documented cases of people surviving core temperatures above 107 degrees Fahrenheit, but there are also many cases of people dying at much lower temperatures. The body is a complex system. Heat-related injury and death are the result of complex responses to heat, not the heat itself.

The information in this post, except where noted, is taken from a document produced–or at least presented–by the US Military (service members are at high risk for heat stroke, therefore the military is interested in the issue). The “report date” of the PDF is listed as 2012, although since it is evidently a chapter in a longer book, I don’t know if the report date is earlier or later than the copyright date of the book. I don’t know how old this information is. It’s a dense read, but I’ve attempted to summarize the main points below.

How Heat Stroke Works

Not everyone is equally vulnerable to heat stroke. There are long lists of circumstances that create higher risk, so many that it might seem everybody must belong to at lest one of them—but it’s important to note that some risk factors are a matter of choice (running marathons on hot days) and some are not (being very young, very old, already ill, or poor). There are obvious social justice issues here, as I’ve discussed before.

Interestingly, several risk factors do not involve simple vulnerability to heat (as in our marathon runner, or a home-bound elderly person without an air conditioner) but rather impairments of the body’s ability to respond. A sunburn or a heat rash can impair the body’s ability to cool itself, for example. Illness or inflammation (e.g., pneumonia) makes heat stroke more likely. Heart problems, certain medications, or low potassium or sodium levels also either make heat stroke more likely or more dangerous. These facts alone should suggest the medical complexity of the problem.

Heat stroke is also a much more drawn out process than the idea of cooking would imply. Literal cooking ceases as soon as the object being cooked cools, but heat stroke isn’t over when the victim’s core temperature is brought back to normal. If he or she lives long enough, the bodily changes initiated by the heat will continue to play out. The patient will probably run a fever (which actually helps the body heal), and may also go through periods of abnormally low body temperature.  Kidney failure will probably occur between two and 24 hours after the initial collapse. The liver will likely fail after 24 to 48 hours. Mortality rates often rise about a month after mass heat stroke events (like heat waves), after patients have been discharged. The risk of dying from cardiovascular, kidney, or liver disease can remain elevated for 30 years. There may be long-term cognitive impairment. And and since many illnesses or deaths are either never recognized as related to a patient’s heat-stroke history, or never reported as such, the true prevalence of these problems is likely much higher than the data we have indicate. There has been little research done on how these long-term problems happen, and no one really knows what to do about it yet.

The bottom line is that the number of people who die of a heat wave is much higher than the number of people who die in a heat wave.

Heat stroke is actually several processes, although the whole story is not yet clear even to scientists.

The dominant process may actually be an immune response called Systemic Inflammatory Response Syndrome (SIRS). This is the same–or at least very similar–to what happens when an infection enters the bloodstream, a condition called sepsis or, less technically, “blood poisoning.” Its symptoms include fever and a whole series of both helpful and non-so-helpful biochemical changes.

Heat-induced SIRS is actually not caused directly by heat. Instead, when the body redirects more blood flow to the skin (heat stroke victims are typically bright red), the internal organs necessarily get less. Insufficient blood flow can damage the gut lining, causing it to leak endotoxin into the blood. The endotoxin, in turn, triggers SIRS–if severe enough, the endotoxin or SIRS (I’m actually not clear which–it looks as though scientists might not be sure, either), destroys the major vital organs, causing death.

Injection of endotoxin alone (into animals) triggers the clinical symptoms of heat stroke.

Another important process is DIC, which stands for Disseminated Introvascular Coagulation. Essentially, the blood starts clumping up, leaving the blood remaining in circulation way too thin. DIC can be caused either by tissue damage (sepsis is listed as a common cause, suggesting that DIC can be caused by SIRS–the immune response I just described–although that is not clear to me from the article) or by direct heat injury to the vascular system.  Besides the real risk of bleeding to death, DIC also causes, or helps cause other problems associated with heat stroke.

DIC can cause kidney failure, for example. But kidney failure can the proteins released by muscles damaged by SIRS, or by heat toxicity itself.  It can be difficult to tell which problems are causes and which are results.

Heat stress is one of several possible triggers for the release of cytokines, a class of messenger proteins that in some circumstances are a necessary part of healing–but experimental injection of these proteins triggers heat stroke symptoms including excessive body heat. In other words, the body doesn’t just get sick because it gets too hot—it also gets hot because it’s sick. Exactly what role cytokines play in actual heat stroke isn’t known, yet, but cytokines are involved in many of the processes and subprocesses of heat stroke.

There are several possible treatments for heat stroke being developed based on this more detailed understanding of the malady, but so far, heat stroke is much easier to prevent than to treat. Prevention consists not just of staying cool, but also in becoming adequately acclimatized–general good health and fitness, plus a recent history of being uncomfortably but not dangerously hot fairly often dramatically increase the body’s ability to safely withstand heat. In other words, HAVING a working air conditioner can save your life, but using it often (hiding from summer heat) puts you more at risk for those times when you do have to get by without it–if, for example, there is a power outage during a heat wave.

So?

All of this might sound like unrepentant geeking out on my part. I am, in fact, an unrepentant geek, but my primary motivation for this post is, as I said, to take a close look at a malady likely to become ever more familiar, both to us individually and as a matter of public health policy.

One study that looked at the UK has predicted that, as a result of global warming, the incidence of death from heat stroke in that country will double by 2050. That’s only just over thirty years away.

 

 

 

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Clear and Present Heat

At least eight people are dead, countless others injured, victims of a preventable disaster that has been exacerbated by politics.

I’m not talking about another shooting.

I’m talking about the heat wave in the American Southwest. Temperatures have reached above 120 degrees, F. Step outdoors into something like that, and you could develop heat stroke in a couple of minutes just by standing around. Heat stroke, remember, is a life-threatening condition in which the body’s cooling system fails and the organs literally begin to cook. These aren’t just unusual conditions for the United States, which is not, after all, tropical, this heat wave would be significant anywhere in the world.

The detail that really jumped out at me was the plane that couldn’t land in Phoenix because the pilot was afraid the hot runway would explode the tires. It’s not that hot weather has never impacted aviation before, but it’s hardly common practice in the US.

Is this global warming? Wrong question, of course, but yes. As I’ve discussed before, even a small increase in average global temperature yields a dramatic increase in the frequency of extreme heat waves, because of a simple quirk in the way the frequency of anything works—extreme events are typically rare, and the most extreme events are exceedingly rare. A rising average temperature makes triple-digit temps slightly closer to normal and therefore a lot less rare.

And we’ve known about global warming long enough now that if the world had acted quickly and decisively back then, our average temperature might not be so high now. This heat wave might still have happened, but it would be less likely. Those eight people might still be alive today.

Lest my comparison to a mass shooting seem exploitive, let me remind you that more people die in the US every year from heat than from all other natural disasters combined and that thousands more die from medical conditions likely exacerbated by heat. The affected are disproportionately the very young, the very old, the ill, the disabled, and the poor. In other words, the vulnerable among us are dying at a shocking and tragic rate from causes that American energy policy is unquestionably making worse—and making worse knowingly.

This is a human rights violation.

The irony in all of this is that the American Southwest would not have so many people in it today were it not for air conditioners. Seriously, with the invention of air conditioners, huge numbers of people, especially the elderly, migrated to the warmer tier of this country, a redistribution of voters that was pivotal in the election of Ronald Regan (who then took the solar panels off of the White House and famously tried to claim that trees cause pollution). Air conditioners have a terrible environmental impact, and not just through their electoral influence. They use vast amounts of electricity (often generated by burning fossil fuel) and leak powerful synthetic greenhouse gasses as well. And many of the people who moved south because of air conditioners are elderly or ill, and thus at higher risk for heat-related injury. And cities build with air conditioners in mind, such as Phoenix, Arizona, often lack other proven heat-reducing technologies, such as public green spaces and cooling architecture.

I’m not trying to blame the victim here on an individual level; I’m saying that heat waves and their associated deaths do not just happen. They aren’t uncontrollable, random events. There is a degree of randomness, yes, and no one can control the weather, exactly, but we’re looking at the results of energy policy, community planning, even architecture, all developed and carried out as if global warming did not exist when we know perfectly well that it does.

Vote for environmentalists. Seriously. Let’s do this.


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It’s HOT!

Ok, it’s cooling down slightly now, but according to our home weather station, the high of the day was 93 degrees Fahrenheit. In the shade. The heat index reached 110 degrees, likewise in the shade. And we have not used the air conditioner.

No, we are not masochists. We actively manage the temperature inside our house by closing windows and drawing blinds, and it’s been at least ten degrees cooler indoors for most of the day–the temperature’s starting to climb in here now, we’re at 85 degrees, but fans and the option to take a cold shower make it bearable. In a few hours, when the outside temps come down, we’ll open up the windows and doors and cool down the house again and I will go for a walk. We put off vigorous physical activity, or anything that could heat up the house, like cooking, until the evening.

People used to live like this, adjusting daily activity levels to cope with the heat and using architecture, such as high ceilings, thermal mass, or, as in our case, excellent insulation, to keep living spaces as cool as possible. In some communities, in some parts of the world, such methods are still the standard. All our neighbors, on the other hand, seem to be running their air conditioners.

Air conditioners are a problem.

Not only do air conditioning systems use a lot of electricity–about 20% of US residential electrical consumption goes towards air conditioning alone. Even more seriously, the coolant inside air conditioners is a very serious greenhouse gas, sometimes thousands of times more powerful than carbon dioxide.  I want to go through that part in more depth, because it can be confusing.

Air conditioners (and refrigerators and freezers) work on the principle that the temperature of a gas is related to its density. These machines all feature a closed loop of some kind of gas. At the beginning of the cycle, the gas is compressed, making it hot. The hot gas then flows through a radiator-like coil, where it cools off (and condenses into a liquid). Then it is re-expanded–and now it’s much cooler. The process is something like wringing out a dish towel, squeezing the water out so that when the cloth expands again it carries much less water. The cooled gas then pulls heat out of the room (or out of the refrigerator) and then goes through the cycle again. The coolant itself could be any of several different kinds of gas, but for decades chlorofluorocarbons (CFCs) were the standard because they’re non-toxic. Unfortunately, they are also greenhouse gasses and ozone-layer eaters.

When CFCs’ role in ozone depletion was discovered, the world stopped using them, as per the Montreal Protocol, although some CFCs lingered in older machines. They were replaced by HCFCs, which were less dangerous for the ozone, but worse for the climate. HCFCs were then replaced by HFCs, which do not damage the ozone at all, but are still very bad for the climate. The problem is that the Montreal Protocol only protects the ozone; there is no equivalent to protect the climate and thus no legal mechanism to limit the use of HFCs.

One complicating factor is that all of these chemicals can be called Freon, a brand name that covers multiple chemicals. So it’s easy to hear a lot of conflicting stories on whether Freon has been banned or not; the truth is that some Freons have been and others have not.

Refrigerant systems do not vent coolant when they are functioning normally; running your air conditioner does not release the gas. However, systems can leak. Worse, once the gas is created, it will almost certainly get into the atmosphere eventually. Freons don’t biodegrade, so no matter how much time goes by, they are still a threat to the climate. Choosing not to run your air conditioner, as we do, does not actually help with Freon. Only not getting the machine in the first place does that. But not running the air conditioner does cut down on electricity use, and that matters.

Climate-neutral refrigerants do exist, but have not yet won regulatory acceptance. There are cooling systems advertized as “green,” but usually because they use less electricity. That matters, too, but efficient air-conditioners, refrigerators, and freezers still contain those powerful greenhouse gasses. Keeping those systems in good repair, so that they do not leak, is important, all of this, efficiency, preventing leaks, everything, is all about making a situation less bad. Only switching to climate-friendly coolants–or giving up the machines–will solve the problem.

For individuals, efficient machines are a good intermediate step, but for society, they are a drawback. For one thing, the more efficient machines get, the more people use them–often resulting in even more electricity use. For another, cheap air conditioning leads to dependence on artificial coolness. For example, huge numbers of elderly people have retired to sun-belt cities. Not only is this demographic more vulnerable to heat-related injury and illness, but those cities have been developed with air-conditioning in mind–without architectural and community-planning details known to bring down the heat, like high ceilings, good night-time ventilation, and community green spaces. The result is a series of intense heat-islands filled with people who need air conditioning as a matter of life and death.

So what’s the value of an individual family, like ours, going without air conditioning on a day like today?

It does reduce electricity use, sometimes a lot. Just as important–or maybe more importantly–it’s a good way to remember that air conditioning really isn’t necessary much of the time, a way to remember that we as a society can turn the machines off, except for occasional therapeutic use. If going without air condition seems difficult, just remember–by turning on the chillers we’re actually making our days even hotter.

Indoors and outdoors, the temperature is now 86 degrees–outside, the temperature is falling. It’s time to open all the windows and doors.

 


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The Ecology of Predator and Prey

This is another article I wrote in college about coping with various kinds of worry and grief, including that related to global warming and other environmental problems. I am not personally grief-stricken at the moment. Instead, I am tired and pressed for time, having just returned from a few days’ vacation. Hopefully this essay will prove food for thought.

Just before Yule this past year, I was chatting on the phone with a friend of mine, Robert, while doing some sewing. I turned to do something in the kitchen only to discover upon my return that my cat, her ulcerated tumors bleeding again, had covered my workspace, including my dress pattern, with irregular, red spots. I hustled around trying to separate my patterns so they could dry and protect my fabric without interrupting the flow of conversation, whose subject seemed bizarrely civilized under the circumstances; we were discussing the genome of the grape and the proper ways to serve different kinds of wine while I stared, transfixed, at the red, Rorschached blotches like footprints, stalking, taking, slowly, my cat.

Here, observe, three views of life on Earth.

One:

Saturday morning in January, warm, hot as May; the breeze moves, gentle, as I stand on the sidewalk waiting for the bus by the Ethan Allen furniture store and St. Phillips Lutheran Church, chickweeds growing in delicate riot by my feet, so far so good, but also dandelions, clover, greening grass, while the trees stand mute above like skeletons. This isn’t right; though the air is pleasant on my simple skin I can’t enjoy it. This weather is as apocalyptic as last summer’s heat waves when I lay, sick and dreaming, too hot to work, all thought, all feeling driven off by the eternal, heavy, heat, save one; this isn’t the way it’s supposed to be, but this is the way it is going to be, more often now, because of us. A funeral procession drives by, headed by slowly flashing police escort, dozens and dozens of cars of mute, hard-eyed people. Most of the cars have only a single passenger, or at most, two. An oil truck cuts through the line to make a delivery to the strip mall behind me, its presence as lyric to the day as a line of poetry. I wonder, whose funeral is it?

Two:

My cat wants to go out, and I can deny her nothing, except for all the things I have denied her and all the things it simply isn’t mine to give; this leash, for example, is a compromise between her exuberance and her body, too sick to take a rabies vaccine. She has never gotten fully comfortable outside and never developed her body to its feline potential; as far as I know, she has never climbed more than a few feet up a tree. Probably, she never will, now. Maybe she might have if I had simply let her out and hoped she didn’t get bitten, or maybe I should have gone out with her more, for longer. Who am I to draw this line here? Who am I to bring a cat in out of the sun just because I have something else I need or want to do? These are judgments I do not feel competent to make and I never have felt competent to make them through these long years of one kind of leash or another hanging between us, yet make them I must. Nothing that I gave her could ever have been enough to absolve her of further desserts. We walk, and she pauses to scent-mark the bottom twig on the lilac bush, rubbing it with her nose, her gums, sniffing it delicately. I sniff it after her and compare the scent to that of one higher up, above the reach of cats and foxes. I fancy I can detect a difference. She stalks a bird in the ivy bed, and I flatten myself out behind her, trying to move forward without frightening her quarry, giving her as much range as possible with the leash, my arm, and the length of my outstretched body. The bird must have flown while neither of us noticed, for now it is no longer there. The day is fine and high and blue, and she doesn’t seem to know she’s sick. Or, at least she doesn’t favor herself, she goes full-bore, always, along her small, plucky way. I mean, what else does she have to do? It’s not like she’s going to get better, it isn’t like she has time to spare in self-pity. She just plays the cards she’s dealt. This animal is a carnivore, whose kind prune and in so pruning, create the reproductive exuberance of small rodents and birds. Fed on organic ground beef through the agency of human loyalty and partisanship, this cat has lived almost nine years. In that time, how many steers have died young for her?

Three:

Walking through campus I can see that the remaining old elms are dying–they have brownish yellow stripes running up the grey and furrowed trunks. My Dad told me about Dutch elm disease when I was little; I have never known a time when its inundations were not part of my history, but as I’ve been watching, over the better part of thirty years, the pandemic has progressed and more of the great cambium fountains have come down. When I was little, I remember, the elms met over the walkways, across the greens. I remember walking, on Community Day, a visceral memory, the smell of cotton candy and funnel cake, a grown-up hand—whose? I only remember the hand—in mine, and above an arching green roof full of multicolored balloons escaped from the careless hands of other children. The greens are open, now, the places of most of the giants taken by smaller trees, another kind of elm, I think, their stems slowly thickening into adulthood. My friend, Robert, is an ecologist who is busy mapping the community types of my state. When I brought him here, on the way to a coffee shop, he remarked that the campus probably counted as Modified Meadow or Modified Hardwood Forest. He’s grasping at straws; this isn’t altered, this is new: American Collegiate, typified by dying elms, manicured grass and a fauna of Frisbee players, grey squirrels, and playful dogs. No matter how aberrant this slow death of trees seems to me, the elms would never have died in such numbers if they hadn’t been planted unnaturally thick to begin with.

Humans are capable of a certain impartial perspective, but at heart we’re partisan animals living in a non-partisan world. Global warming and human-associated habitat destruction are surely no more radical than the asteroid that marked the KT boundary. Life recovered, growing even more diverse in time, and will again; nothing stays the same for long. Similarly, the birthrate of any given species is adjusted to its mortality rate; if it takes three dozen mice born per one that makes it to adulthood to keep even with the hunger of cats, then that is the number that mother mice produce, yet every pup is an individual. One could say each mouse deserves a full and happy life, just as every cat does, but it is the nature of both cats and mice, in their fullness, to produce more than can so live; to lower the mortality rate would require lowering the birthrate which would change the nature of the animals’ lives. Anyway, which individuals don’t get born in that case? Isn’t it better to live for at least a little while? Like climate change and disaster, death and even personal tragedy are just part of how things work; if these things did not exist, life as a whole would be different and probably the poorer for it.

Yet we are partisan, and we must behave in partisan ways; we act, we do one thing rather than another, and so we must make choices based on some judgment, some assessment of value, even if the value is a purely private priority. Mass extinctions happen, and in the grand scheme of things may not actually be a problem, but I must throw my small weight either for this one or against it, and I do not want a mass extinction on my watch, on my conscience. Plants, animals, and diseases do invade each other’s territory; humans may be causing an unprecedented invasion, but we are not causing the only one. Communities adapt and change. Diversity will recover. Nonetheless, I want my trees not to die of some imported disease, even if their gothic branches were themselves an artificial presence. And I want my Gertie to have not had cancer to begin with, I don’t care if she’s no better or worse than a mouse or a beef steer–or me, for that matter, I wanted this one, this particular one, to get the proverbial sun, moon and stars. That I, a mortal human, couldn’t reach them for her does not reduce the injustice any less.

We live in a world of change and transformation; one thing eats another, one thing subsumes another, one thing takes another’s place. Even if it were possible to pick sides, once and for all, on moral grounds, it would not be possible on physical grounds, for not only does the success of a predator mean the failure of a prey animal–and vice versa–but it is the very opposition, the very dynamism of the system, that makes the system in the first place. Under whatever happy facade of civilization or rationalization, we are incontrovertibly members of a system where things break and change and die as an inevitable matter of course, without violating the integrity of the whole. Under whatever veneer of educated perspective, however, we remain organisms who fight and try to win.