The Climate in Emergency

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


Leave a comment

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.

 

 

 


Leave a comment

Seeing Patterns

Last week, I had the distinct pleasure of a hike on Mount Desert Island with my friend and teacher, Tom Wessels–the same man who lead the hike in the White Mountains described in my post, The Ghost of White Birches. Only, then he was leading an organized group activity associated with the school I’d just graduated. This time, for the first time, we were just friends going hiking together.

Myself, my husband, our elderly but still spry dogs, and him.

Switching contexts can have an unpredictable effect on relationships, and I can be slow on the uptake when the rules change. I had left it to Tom to suggest a hike, rather than saying so myself, because I did not want him to think I was expecting him to work on his day off. But as it happened, I need not have worried. Nothing had really changed between us. And while he had no planned lectures, no educational objectives, and had not previously hiked our whole route (as a professor, he appears to meticulously plan everything), he still kept us appraised of the cultural and natural history around us, knowing and sharing our interest. Tom is not one of those people who wears radically different hats for changing circumstance. He is always and exactly himself.

He told us that part of the trail we followed ran along the bed of the first road on the island. He pointed out a big-toothed aspen so furrowed with age that it looked like an ancient cottonwood, and how two other trees of the same size and species nearby must be much younger, having smoother bark.* He commented that the rhodora was coming into bloom. He answered questions, asked and unasked.

“Sap,” he said, spotting me examining a mass of white stuff at the base of a tree. I had thought it was either sap or bird urine and that either way it indicated some story. “These spruces are not doing well. Fungus comes in, then ants, then woodpeckers. Carpenter ants can’t excavate healthy wood.” The sap had flowed from the work of a pileated woodpecker, going after carpenter ants.

I knew from previous conversations that one of the reasons the spruces are becoming more vulnerable is climate change.

Much of Mount Desert Island is dominated by spruces, a cold-tolerant genus of tree that is rare at this latitude. The island–and the coast of Maine generally–is different because the frigid Humbolt Current bathes the land in cool sea breezes and cold sea fogs. According to rangers at Acadia National Park, which includes much of the island, the Gulf of Maine is now warming faster than almost any other water body in the world. Lobsters are moving north, to the detriment of lobstermen in southern New England. Southern fish species are moving in. In warm years, every puffin chick in the state starves to death, unable to swallow the larger, southern fish their parents bring.

I was right to think the white stuff at the base of the tree held a story.

Tom sees patterns. In a somewhat different and still less-developed way, so do I. A hiker without this kind of knowledge would see a pristine wilderness, protected in perpetuity by the US Park Service. Tom sees spruces not doing well (and paper birches dying off, lobsters moving, puffins starving) and is saddened.

There is a certain comfort to be had by sharing your reality with another. We chat about our home, mine and my husband’s, in Maryland, and how our forested lot prevents our having a garden, or a solar panel, or a wind turbine, but does protect us from the damaging effects of winds. In the ten years I’ve been there, I say, we’ve survived two hurricanes (Sandy and Irene) and a derecho, and the wind mostly flows over the tops of the trees.

“Those will happen more frequently, because of climate change,” comments Tom. We know. My husband talks about the changes he’s seen in Assateague Island in the forty years he’s been watching the place. Casual visitors don’t see that, either, only an unspoiled, wild beach, but we have friends who were married in a house on that beach and the house is not there anymore. The place where it stood is now several yards off shore. Maryland is slowly sinking, a natural subsidence triggered by the retreat of the glaciers tens of thousands of years ago, but sea level rise from climate change is real, too.

Last month, in St. Michaels, a town on the Chesapeake Bay, I saw water quietly lapping over the edge of the town dock, standing a few inches deep on pavement. Nobody else said anything. Nobody acknowledged it was happening, let alone extraordinary. Tidal height can vary. There is the influence of the moon’s phase, of course, since full moons and new moons produce extreme tides, and an onshore wind can pile up water on the coast. If both occur at the same time, tides can become extraordinary quite naturally.

But the town dock would not have been built where it was if flooding were normal at the time of its construction.

Last night I dreamed that nothing I did turned out right, that I was driving down winding country roads, lost, that the roads became dangerously, fantastically steep so I pulled over, only to watch my parked car roll down hill into the back of another. The metaphor of my subconscious is clear; I don’t know what to do about any of these patterns.

My mother and I discuss politics over breakfast. We are both worried about the survival of democracy. I go to bed with a hard knot of anxiety, the same nauseous fear that has plagued me since the election. I attend marches, write political letters, sign petitions, keep this blog, but there is something else that must be done, some stronger, more effective way to fight, but through the fog of anxiety, I don’t see it. Other than to acknowledge the truth, share my reality, I don’t know what to do.

 

  • The rate at which wood grows varies, as many people know, but the bark of each species grows at a nearly constant rate. Thus, an individual growing more slowly than normal for its species will have thicker, more textured bark. With some few exceptions, trunk size plus bark texture gives a better indication of tree age than either does alone.

 


Leave a comment

What the Science March Was Like

I went to the March for Science, as promised, on Saturday. My husband went to our local satellite march (he was brainstorming chants for days ahead of time. My favorite of his: Science Yes!/Silence No!), but I felt a need to be in DC. So, I arranged to spend the week with my mother, and she and I bought tickets on a bus chartered by the university in my hometown. We went marching together.

My mother, incidentally, is a scientist, a geologist, specifically. I am trained as an ecologist, though I’m a science writer, rather than a researcher. It was our march.

It was not an ideal day for marching. The rain started just as we got on the bus, and the sky proceeded to variously spit and drizzle throughout the day, while the air temperature held steady around 60° F. Hypothermia weather. Heat travels much faster through water than through air, so wet weather gets dangerous at a much higher temperature than dry weather does. A four hour rally preceded the actual march, which took an additional two hours or so, a long time to stand or walk out in the rain. We kept ourselves as dry as possible and checked in with each other frequently.

I’ve been cold in DC before. At my first climate march, four years ago, the weather was cold and blustery. But that was in February. This time, in April, the grass had greened up, most of the trees had leafed out, the spring color enlivened and relieved by white and pink flowering dogwoods and the blond and white monumental architecture of the city. Tiny, winged elm seeds and fallen, string-like, oak flowers clotted together in the streets, and the slicked and flowing water turned everything silver and vague beneath dark, grey cloud. Sometimes the pavement shone with isolated grains of glitter, presumably shed from someone’s costume or sign. There is a loveliness possible, on a rainy day.

Our bus dropped us off near the Capitol Building, but the rally and the beginning of the march was at the Washington Monument, so we had to walk a good distance just to start. Clumps and clots of people, some carrying signs, moved in the same direction, presumably fellow marchers. One of my favorite things on march days is watching people converge, seeing actual, undeniable evidence that other people–maybe a lot of other people–are showing up.

As we arrived, we could hear the rally already in progress. The grounds were full of streaming lines of people. We went through security (a simple, efficient process, but one that did not occur on prior marches) and joined the crowd, which seemed largely organized around a big stage and a scattering of large video screens and tower speakers hung from cranes.

Unfortunately, I’m somewhat sensitive to sound. I don’t mean my hearing is especially acute, I mean that noise that is too loud drives me nuts. We found that there was no happy medium between being too close to those giant speakers for comfort, and too far away to clearly hear what the people on the stage were saying–which was too bad, because some of them seemed like they would have been interesting. Bill Nye was one of them. I have no idea what he said. Some of the others introduced themselves by saying their names, institutional affiliations, and the proud shout “I am a SCIENTIST!” Everybody cheered. I have no idea what they said, either.  But there were bands playing in between each speech, and the music was good.

Instead of listening to the people I couldn’t hear (I really hope all of that is posted online somewhere so I can watch it), I milled around, trying to spot anyone I might know, looking at signs, and people-watching. A few people wore pussy hats. One person wore a polar bear costume. Two dressed as dinosaurs and fought with each other and inspired frantic barking by various small dogs. At least one person wore a Beaker costume, as in the anxious Muppet who says “meep!” and works as a lab assistant to Dr. Bunsen Honeydew. Beaker showed up on a lot of signs, too. He seemed to be popular, as were t-shirts from my beloved XKCD (the best geeky internet comic, ever).

Organizers had suggested we either wear whatever we normally wear as scientists or dress as our favorite scientist. Accordingly, I saw several Einsteins and Darwins and at least one Bill Nye (other than the real Bill Nye, of course, whom I did not see except on the giant screen). I had been planning on wearing a hat similar to one worn by one of my science heroes, Tom Wessels, and I wished sincerely I had not forgotten it–that hat would have kept the rain off my head.

Finally, we surged out of the rallying grounds and onto the march route…and then we stopped, standing still in the road. After a few minutes, a strange sound issued from up ahead and grew and swelled…people were cheering! The wave of cheering passed over us–we duly cheered as well–and swept on behind us, and no, none of us knew why. We advanced maybe fifteen feet and stopped again. This went on for almost an hour, start and stop and start again, interspersed with cheering, and by the end of that hour we’d traveled only a few hundred feet.

“This is a good sign,” I told the people behind us. “The same thing happened at the climate march in New York, and that march was really big.” They seemed to agree with me, so I said it again to someone else. I meant that maybe there were so many people that we’d clogged up the route. I really hoped that was the case. Another wave of cheering passed over us.

In the middle of a demonstration, you can’t tell how big it is or why anything is happening.

I people-watched some more, and found the Wonder Twins, in full regalia, holding a banner, which I forgot to read because I was busy reading the Twins’ capes–which identified the scientific specialty of each and the fact that one of them was transgender, the other cisgender. The original Wonder Twins did not wear capes and had nothing to do with science that I remember, but I liked the costumes and we chatted for a while.

I read more signs.

SCIENCE HAS NO AGENDA

MARA LAGO WILL BE SO FAR UNDERWATER, YOU WON’T BELIEVE HOW UNDER WATER IT WILL BE

HAD POLIO LATELY? ME NEITHER: THANKS, SCIENCE!

BF IS MY BFF! (BF Skinner reference)

MY MONKEYS CAN WRITE BETTER EXECUTIVE ORDERS! (under copies of two paintings that did appear to have been made by monkeys or apes)

IT’S SO BAD, EVEN THE INTROVERTS ARE HERE. PLEASE DON’T TALK TO ME.

There were a lot of signs in which SCIENCE was an anagram for something, or written out using the Periodic Table or other suitably sciency symbols. There were quotes from Einstein, Thoreau, Emerson, Neil DeGrasse Tyson, and Carl Sagan. There were lots of signs using “trump” as a verb, as in “facts trump opinions.” There were puns on the word “resistance” involving electronics. There was a sign with the words SCIENCE and TRUMP separated by three parallel lines with a slash across them. I asked the man holding it what the symbol meant. “Exact opposite of,” he said. A popular sign read “science is like magic, except real.”

Which is pretty much true. It’s common knowledge that many branches of science grew out of magic–chemistry began as alchemy, and so on. Arguably, it remains magic, it’s just effective magic. I mean, any good wizard claims to have special knowledge and insight into how the world works and to be able to transform the world as a result. Scientists and engineers do just that. It actually is possible to make lead into gold, and gold has been made from bismuth. It is possible to change the entire climate.

What this march reminded me of were the Druids. I cannot find a really reliable source to cite here, so please don’t take my word for this, but I have read that the Druids and bards together were the educated class of the Celts and performed social roles that we now might identify with clergy, law, art, and science. And they were politically powerful, standing up to fight the Roman Empire. Everyone knows that the Romans tried to eradicate the Christians, but they quite literally slaughtered the Druids, too. Well, maybe the Druids are rising.

Perhaps the people carrying the REVENGE OF THE NERDS signs harbored a similar sentiment.

Other than the mysterious cheering, we were mostly quiet. A group of men beside us discussed possible chants: “If P is low/the null hypothesis has got to go!” which is definitely catchy, but instead of chanting it they began quietly discussing whether they were remembering the principal correctly, given that one of them hates statistics and the other is a physicist with dyscalcula (the math equivalent of dyslexia). I have a similar problem, and the physicist and I commiserated for a while. We never got around to chanting about P values. Around then was when I spotted the glitter floating by on the rainy street.

We still hadn’t gone anywhere. The advantage to not going anywhere was that we were still relatively close to the stage, and we danced to keep warm as long as they kept playing. My mother recognized the groups, though I did not. It was fun.

Finally, we got going, and some chants did start up. “Science, not silence” was popular. My favorite was “don’t pretend that you don’t care/science gave you back your hair!” My other favorite was “What do we want? SCIENCE! When do we want it? AFTER PEER REVIEW!” Which is extra-awesome because I first saw it as a joke on social media captioned “why scientists can’t have protest marches,” or some such. But we can, and we did, and peer review is important, so there.

We continued marching, without incident, back to the Capitol building and our bus home, though we did pass a few counter-demonstrators who seemed to think that we were all atheists (they held signs asking whether we had been brainwashed by professors who denied and mocked God. Of course, I can’t imagine any real science professor even mentioning religion in class, much less mocking it). Other demonstrations seemed to be embedded in ours, like inclusions in some larger mineral mass. We passed socialists handing out leaflets, anti-fascists with their own signs and chants (I suspect most of us agreed with them, but they did seem to be their own group and held their own miniature rally at the end of the march), and an abortion rights contingent, complete with their own counter-demonstration of pro-life people. I’ve never seen anything like that before, this symbiosis of highly disparate groups within the same overall system. My mother and I stopped, once, so she could buy lunch from a food cart, and once again so she could buy a dry sweatshirt to wear on the bus. Did I mention it was raining?

I was struck, all but literally, by how different this march felt from every other political protest or demonstration I have attended. There was no sage smoke. There was very little drumming, and no one costumed as Uncle Sam or Big Daddy Oil, or other such motifs. At all of the others I kept seeing the same signs and hearing the same chants, from march to march, regardless of what the specific event was supposed to be about. At the pipeline rallies, a large number of participants carried signs that had nothing to do with the land use issues and Native American rights placed front-and-center by organizers. No, it seemed to be just the usual suspects in for a generalized pro-environment event. But at the science march, it was all science.

A few “I’m with her” signs with pictures of the planet on them could have been previously used at other events, but mostly it was incredibly focused. Even the typical chants were missing. We knew them–someone started up with “show me what a scientist looks like/this is what a scientist looks like,” a clear riff on a recurring chant about democracy, but even that died out pretty quickly. It was just a different type of crowd.

When we, the marchers, spoke to each other, we tended not to make statements. Instead, we asked questions, mostly about what each others’ signs and shirts said or meant. “What kind of scientist are you?” was frequent. The kind who asks questions, apparently.

This march even felt different.

In every other demonstration or protest I’ve been on, there has been a definite pep-rally vibe. Someone starts chanting “the PEOPLE, UNITED, will NEVER be defeated!” and you feel all optimistic, like yeah, power to the people! And only later, afterwards, do you remember that if the people were actually united around progressive politics, we wouldn’t have elected Donald Trump, and anyway, united people are defeated routinely by folks with money and guns. We come back, but we do get defeated. The pep rallies help, of course, for a while.

This time, I felt no such surge of optimism–but no pessimism, either. We didn’t need to boost ourselves up. Our message wasn’t “we’re going to WIN,” but simply “we are here.” And, even more simply, “the world is what it is.” After all, we’re scientists. As many of the signs pointed out, facts don’t care whether you believe in them or not.

Whether we win or not, global warming is real. Whether scientists get the funding they need to watch it or not, anthropogenic climate change will continue to happen until we collectively stop making it happen. The world needs scientists, and individual scientists, of course, are part of the needing world. But the truth of that need exists whether the rest of the world recognizes it or not. There is a certain serenity in that.

It was nice to rally with the scientists, to see signs and hear chants that you actually need to think, to know something, or to ask questions to understand, to be in among the crowd that has never been the in-crowd, and know that today, this is our place, 40,000 of us strong. Today, we are the cool kids.

But it wasn’t a pep rally. It didn’t need to be. It was just rockin’ with the Druids in the rain.

 


1 Comment

Ninety-Seven Percent Pure

When I was kid, a popular soap brand advertised itself with a slogan similar to the title of this post. I’ve just done an internet search on the subject, and learned that the brand was Ivory, the claimed percentage was 99.44%, and there are multiple stories on where the number comes from. In most versions, the figure comes from a chemical analysis of the product’s ingredients and the .66% remainder is not necessarily an “impurity” in the negative sense (rat droppings, for example), but simply material that does not, strictly speaking, count as soap–fragrance, perhaps.

Anyway, it was an iconic, and, I’m sure, very successful ad campaign, but whenever I saw it I was always distracted by the thought of that .66%. Did I really want to wash with a bar that contained .66% impurities? Why are they boasting about a product that isn’t really completely pure?

Whatever. I have no actual opinion on the brand. It was just an ad campaign.

The point is that the scientific consensus is commonly presented as being even less pure than Ivory Soap: 97% of climate scientists reportedly agree that global warming is caused by humans. Obviously, I need no persuading that anthropogenic climate change is real, but the figure bothers me. It leaves itself too open to well-placed questions–above all, scientists don’t vote on the truth by majority rule, so why is the percent who agree even relevant?

So, let’s take a little time and look at this: where does 97% come from, why isn’t it 100%, and who are those 3% who disagree?

Before we go further, though, I want to point out that, contrary to the posts of certain trolls, climate dissidents do not live in fear of bullying by the establishment majority. I’m sure those people aren’t popular at departmental parties, but it is the scientists who do support the consensus who see their work maligned and ignored, who are personally harassed, and who occasionally receive death threats. Researchers who want the easy way out get out of this field, not into it.

So.

Um, 97% of What?

The figure, 97%, comes from several suitably scientific analyses of science. That is, it’s not a result of a public opinion survey, but rather a series of literature reviews and reviews of reviews conducted by climate scientists themselves. These reviews, conducted over a period of years, present various figures, but most place scientific agreement at somewhere between 90 and 100%. The figures vary because the methods vary–and this is important, because while different questions can yield the same answer, the answers mean different things.

Percent of Papers?

The public statements generally refer to the number of scientists who agree, but in many of these reviews, it wasn’t the scientists who were questioned–it was their papers. The distinction is important for two reasons. Most obviously, the same scientist can write multiple papers. The fact that most papers agree with a certain proposition tells us very little about how many humans agree. It’s simply a separate question.

A more subtle point is that while the number of scientists who agree on something is arguably irrelevant, the number of studies that agree matters very much. Science works on the principle of repeated observation. If I claim that an opossum has gotten into my basement, you might well ask whether anyone else who has gone down there has seen it. We’re not going to vote on the existence of the opossum–it’s either down there or it isn’t, whether the majority agrees or not–but we both know a single observation could be wrong. The light’s bad down there, after all. Maybe I just saw my cat, or some old stuffed animal. But if most people who check my basement also see an opossum (or opossum scat, or opossum hair, or other sign), that is harder to dismiss.

97% of visits to our planet’s basement have involved sightings of the global warming opossum.

Percent of Experts?

Several of the studies did survey individuals, but varied in how they defined the pool of respondents. On one end of the continuum were surveys limited to those who regularly publish peer-reviewed papers on climate. On the other were surveys open to people who work in any science at any educational level. A field tech in geology is a scientist, but does not necessarily know any more about climate than anyone else. Not surprisingly, the percent of respondents who agree with the consensus is higher if the survey is limited to people with the most relevant expertise.

Agree With What? And What is Agreement?

The wording of the surveys varied a lot. Some asked if the respondent believed at least some climate change is caused by humans, others if most is caused by humans. Clearly, for some people, the answers to these questions could be different.

A related issue is that many climatology papers do not state whether anthropogenic climate change is real. An even larger number do not make such a statement in their abstracts. Some studies have counted these as denying climate change, others have simply excluded them from analysis. Arguably, most of these should be counted as supportive of the reality of climate change, since the reason they don’t address the question is that the authors regarded the answer as accepted and obvious. Chemistry papers don’t take the time to note that water is wet, after all. Physicists don’t bother to express a professional opinion on whether gravity is real.

In case it’s not obvious, all of the above came from the two sites I linked to above. Both are worth a read.

So, Who Are the 3%?

I originally set out to write a piece about that three percent–who are they, why do they believe what they do, and are they genuine examples of free disagreement, or are they paid shills?

Unfortunately, I haven’t found an answer, yet. It may be that no one knows the answer–if quantifying the consensus was complicated, qualifying the dissent must be more so. How do you define your sample without including at least some people who aren’t legitimate scientists, and without excluding at least some people who are legitimate but maybe don’t act that way anymore because they disagree with the current consensus and go rogue?

How do you get someone to respond to your survey if doing so could expose them as a paid shill?

I suspect that at least some dissenters are exactly that–paid shills. Others are likely artifacts of the analysis. That is, dissenters who don’t really exist, but only seem to because of how a survey was worded or how papers were coded for analysis. Some may well be both real and genuine. But how many fall into each group and who they are and why they believe thus may be one of those questions science has trouble answering.

 


1 Comment

For a Little Boy

I first posted “A Family Expecting” shortly after the birth of my nephew. I have re-posted it occasionally since then, and rewritten it at least once under a new title. I’m re-posting again now for reasons that should be obvious to friends and family–and I figure now is also a good time to remind people that what we’re doing really matters.  Although this story is a fantasy, it is based on the published results of climate models. Please check out the original for the research links posted at the bottom

Yesterday, my first nephew was born. He is small and wrinkled and has acne on his nose. He has wispy black hair and silvery-blue eyes. He knows the voices of his family and the scents and sounds of the hospital. He does not know about his home, going to school, or getting a job. He doesn’t know about casual friends, mean people, or birthday cake. He doesn’t know what the world will be like for him.

Neither do we, obviously, but if he lives to see his 89th birthday then his life will touch the end of the century, spanning the same period of time across which many climate models dare to predict. He comes from farming people in the Piedmont of the Mid-Atlantic. If he stays here and inherits his parents’ farm, as he might, then his life will also be the life of this landscape. What will he see?

This child will go home soon, and become the son of the land. He’ll rest in a cradle on the floor of a barn, his mother rocking him with one bare foot as she directs customers picking up vegetables in June. In two or three years, he’ll carry handfuls of squash guts as gifts for the chickens and a rooster as tall as he is will look him in the eye and decide he’s ok. He’ll listen to his parents worry about droughts. He’ll learn to hope the heavy rains don’t rot the tomatoes and that rising gas prices don’t break the bank. There will likely be more such worries as he gets older. Summers will be hotter. His mother will say it didn’t used to be like this, but grown-ups always say that.

According to the IPCC, by the time he’s a teenager, temperatures in the Mid-Atlantic will average maybe two degrees higher than they did during his mother’s childhood. That does not sound like much, but averages rarely do. One degree can turn a pretty snow into a destructive ice storm.

Warming, in and of itself, will be good for the crops; only a local rise of about five degrees Fahrenheit or more hurts productivity. That’s unlikely to happen here until my nephew is a very old man. But the Great Plains may warm faster, enough to cause a problem; he could study the shifting agricultural economics in college.

Our area could either get wetter or drier. Parts of northern and central Mexico will almost certainly get drier, maybe dramatically so. These areas are dry already, so I imagine a lot more people will start heading north. My nephew will discuss the refugee problem with his friends, lean on his shovel in the morning sun, and wonder if the United States has a responsibility to keep Mexicans from dying when Congress is already deadlocked over how to pay for the flooding in New England. Seems you can’t keep a bridge built in Vermont, anymore. He takes off his sun hat and scratches his thinning hair.

Years pass. My nephew thinks about his upcoming fiftieth birthday, and also about New York City, where three of his grandparents grew up. It’s turning into a ghetto. It’s not under water, exactly, though the highest tides creep slowly across abandoned parking lots in some neighborhoods, spilling over the older seawalls. The problem is this is the second time it’s been stricken by a hurricane, and now no one can get the insurance money to rebuild. The same thing has happened to New Orleans and Miami. Boston may be next. Those who can get out, do. Those who can’t, riot. They have a right to be angry. His daughter is pregnant with his first grandchild. My nephew cannot keep his family safe indefinitely, but he’s glad his parents taught him how to grow food.

More years pass, and my nephew turns sixty-five. He proud of his skill as a farmer, especially with the way the rules keep changing. The farm seems to be in Zone 8, these days. He’s got new crops and new weeds. He has friends in southern Maryland who haven’t had a hard frost in two years. Maybe this year they will; Farmer’s Almanac says it’ll be cold. Last year, he and his wife took a trip through New England and let his kids take care of the harvest for once. They stayed at romantic little bed-and-breakfasts and took long walks in the woods, holding hands. There was white, papery birch-bark on the ground, here and there, the stuff takes a long time to rot, but he knew he’d have to go to Canada if he wanted to see one alive. The American white birches are all dead, killed by a changing climate. It’s sad.

Eventually, my nephew becomes a very old man, a spry but somewhat stooped 89-year-old, mostly bald, with great cottony billows of hair spilling out of his ears, his breathing deep and slow and marred by occasional coughs and rumbles. He has lived long enough to see more change than any prior human generation has, and that’s saying something. A lot of the change is environmental, but not all of it. Major technological shifts have reworked the country yet again, and the entire political and economic center of gravity has pulled away from the coasts. He is aware of this upheaval intellectually, but viscerally he is used to the world he lives in. He lives well. He is loved and he is useful. No dramatic disasters have befallen him–the worst-case scenarios have not played out, but mostly he’s just been lucky. Plenty of disasters have happened to other people. My nephew is sympathetic. He writes his Congress-people and gives generously through his church whenever he can. But a lot of good that could have been done decades ago wasn’t.

I saw my nephew tonight. He’s at home now, wrapped in a blue blanket like an animate dumpling, slowly fretting against the swaddling. His wrists and ankles are as thin as my thumbs. He’s too young for baby fat. He doesn’t know what his future holds. And neither, really, do we.

——————–

I wrote the above fantasy several years ago and many of my predictions have already come true. My little nephew has indeed learned about birthday cake (I hope he does not yet know about mean people) and has carried treats to the chickens, though he prefers the company of the goats and can imitate their voices. More darkly, Manhattan was hit by a major storm-surge (Superstorm Sandy) and Miami Beach now floods regularly due to sea-level rise. I don’t think my nephew knows it, but the years of his  life thus far have seen consecutive global heat records broken, two successive record-breaking tropical cyclones (Haiyan and Patricia), rumors of “jellyfish seas,” a major climate-related refugee crisis, the possible California Megadrought, and dramatic, unprecedented fires in Canada, the United States, and Indonesia. Among other deeply worrying developments.

Come on, people, put your backs into it, whatever we make of the future, my nephew will have to live there.


Leave a comment

One Word: Plastics

The title for this post is, of course, a quote from The Graduate, but  the line of inquiry that got me writing today was actually triggered by a different movie. In It’s a Wonderful Life, one of George Baily’s friends tries to get him to invest in a company than makes plastic from soybeans. This detail is irrelevant to the plot–the important thing for the story is that the suggestion to invest in something functions as more pressure for George to settle down, which is does not want to do. That the “something” is plastics is arbitrary, and I ignored it for all of the 948,000 times I’ve seen the movie.

Until this year, when I saw it for the 948,001st time, and thought–wait, soy-based plastic? In the 1930’s? (the movie was actually made somewhat later, but the scene is set before World War II) If they had soy-based plastic then, why do we still bother with petro-plastics now? Why are bioplastics always talked about as if they were new, when we’ve obviously had them for at least ninety years?

The short answer is that “plastic” is not one material but several, and the types of bioplastics that existed ninety years ago were not very useful. They’re not the plastic we’re looking for.

Let me elaborate.

A Primer on Plastics

“Plastic,” originally an adjective meaning “flexible,” has come to refer to a any of a large group of organic polymers (“organic,” in this case, means including the element, carbon). A polymer is a a very large molecule made by stringing together lots of smaller molecules, or monomers. Not all polymers are plastics–DNA, for example, is a polymer made out of protein.

Depending on the polymer, how it is processed, and what additives it contains, a plastic might be clear or opaque, strong or weak, flexible or brittle, cheap or expensive, toxic or non-toxic, biodegradable or not biodegradable.Thermoplastics are made of chain-like polymers and melt and flow when heated–that makes them relatively easy to recycle. Thermo-set plastics are made of web-like polymers and do not melt. They are very difficult to recycle.

Plastics can be synthesized from various feed stocks, including petroleum, natural gas, sugar, and plant-derived oils. Some plastics can be made from either petroleum (or natural gas) or recently-living plant-matter–and the result is chemically identical either way. That is, being made from petroleum doesn’t make a plastic automatically bad, and being made from recently-living plant doesn’t, all by itself, make a plastic good.

Some plastics can only be made from a fossil fuel, but do have bioplastic analogues. But since the analogue is chemically distinct, it won’t necessarily have the same performance characteristics and might be both more expensive to the consumer and less useful.

The long and the short of all of this is that “plastics” is a very broad category and you really have to know which plastic you are talking about before you can say much of anything about it.

The Problem with Green Plastics

Because different plastics have different properties and different advantages and disadvantages, looking for an “eco-friendly” plastic is a good way to get confused or even scammed. Apples get compared to oranges through marketing, and the point of the whole exercise can get lost in the shuffle, unless you remember to think of plastics as a whole group of materials.

Ideally, for each petroplastic on the market today, we want a bioplastic equivalent that does the same job at a competitive price and then biodegrades when we don’t need it anymore.

And indeed, as noted, some petroplastics do have bioplastic equivalents, some of which are even chemically identical. Use of bioplastics would at least get us away from fossil-fuel feed stocks, a definite good thing, even if everything else remained the same. Remember, it is demand for fossil fuels, including demand by the plastics industry, that drives fracking, oil spills, and pipelines being put in where they should not go.

But bioplastics are still synthetic polymers, which means hardly anything can eat them.  They can stick around in the environment forever, clogging up animal digestive tracks and otherwise causing havoc, just like petroplastics can. And some plastics of either origin can shed their component monomers, many of which are toxins.

There are biodegradable bioplastics and there are also biodegradable petroplastics. In theory, either would be a good thing–even if the product were still made from petroleum, reducing the amount of plastic floating around in our oceans forever would be an improvement.

The problem is that true biodegradable plastic–as in, you could throw it on the ground and it will become soil in a reasonable amount of time–is rather hard to find. What you get instead is various versions of disintegration, referred by a  collection of terms that are precisely defined by industry leaders.

Degradable means the plastic breaks up into lots of little, hard-to-see pieces that you can ignore if you want to. The term does not say anything about what happens to those little bits–they could just go on being plastic, which is very bad, because eventually they end up in the oceans where they get mixed up with the plankton that forms the basis of oceanic food webs. Already a really scary proportion of ocean life have tiny bits of plastic in their bodies. Remember that, next time you eat ocean-caught fish.

The first plastics marketed as “biodegradable” in fact did exactly that–broke up into tiny pieces of permanent plastic. These days industry standards require stricter labeling, but fancy terms such as photodegradable and oxydegradable still just refer to how any why plastic breaks down into bits–they promise nothing as far as avoiding the Tiny Plastic Apocalypse.

If you want something that actually breaks down because microorganisms digest it, you’re looking for biodegradable plastic. And it does exist, but that term promises nothing about how healthy the resulting soil is–you need compostable plastic if you want soil that, say, does not kill plants.

And even compostable plastic might not break down unless it is processed in a large-scale, municipal composting facility which, by the way, hardly any municipalities actually have. Your back-yard compost pile might not work, and throwing the stuff in the ocean (which is what will happen to virtually all plastic eventually anyway, even if it gets delayed in a landfill for a few thousand years first) definitely won’t work. You’ll get tiny bits of plastic again.

Even under ideal circumstances, I’m not sure that compostable plastic actually avoids the tiny-bits-of-plastic scenario. The standard tests involve sieving the composted product to make sure all the pieces are small, testing for the presence of heavy metals, and trying to grow plants in it–but they don’t test for the chemical signature of the synthetic polymer itself. Some plastic could get through.

Some people argue that biodegradable/compostable plastic is actually a bad idea. It’s not going to get a chance to compost, and a lot of it probably gets dumped in with plastic recycling by mistake, where it can contaminate whole batches. Some compostable plastics are recyclable in theory, but virtually no facilities are equipped to handle it.

I would not say compostable plastics are bad–rather, I’d say this is another example of why we should not try to simplify our choices into blanket pronouncements: PLASTIC=BAD, COMPOSTABLE=GOOD, etc. There are some circumstances under which a compostable plastic might be the better option. Other times, it might not be.

At this time, the most effective thing we can do is probably to minimize the use of all plastics, while continuing to call for compostable bioplastic options for those times we’re unwilling to do without. Half of the oil used in plastics production actually goes into energy generation, not feed stock. If we can shift the industry over to renewable energy, we can substantially shrink the carbon footprint of plastics.

Bioplastics, Past, Present, and Future

The first plastics–cellophane and rayon–were bioplastics. They still have a place in the market, but the market has grown to include many needs that these products can’t meet. Newer, petroleum-based plastics can and do. Much of the early promise of bioplastics never panned out–Its a Wonderful Life is fiction. Henry Ford’s famous attempt to make a plastic car using soybeans actually involved soy fibers in a phenolic resin. Phenolic resin is Bakalite, a petroplastic.

Over the years, hardly anybody has ever been able to make bioplastics work as a business model except, again, in niches. Modern environmental awareness might expand some of those niches, and ongoing technological development might give us new bioplastics that function better as competitive analogues to some of the petroplastics. Various authors have analyzed the probable economic effects of a shift to bioplastics–production would likely shift to the Midwest, for better access to raw materials, for example.

Sooner or later, we’re going to have to get off fossil fuels entirely. When that happens, bioplastics will be all we have–and we have the technical know-how to make the conversion already. It may be comforting to know that the future need not leave us without plastics, since they are very useful materials for some things–medical equipment, for example. The downside is that we will still be faced with the problem of plastic waste–barring a radical change in technology, it seems likely that even the most compostable bioplastics will still require specialized circumstances to break down. The key will be to keep plastic use to a minimum and to diligently recycle or compost all used plastic items.

The important thing to remember is that, however ubiquitous plastics are now, they didn’t exist much more than a hundred years ago, and most are more recent than that. Most uses of plastics today are simply unecessary.

 

 

 


9 Comments

The Story of Global Cooling

I’ve been hearing climate deniers talking about a global cooling scare in the nineteen seventies for a while now, and I finally got curious about where this narrative had come from–I didn’t think it had been made up whole cloth, but I hadn’t heard word one about it from any credible source, either. You’d think that if climate scientists had thought an ice age was imminent as recently as the seventies, at least some of the scientists I know would mention it occasionally?

So, I looked into it. And I found not one but two explanations.

In one story, Peter Gwynne, a science writer for Newsweek, wrote a short article on an idea some scientists were kicking around at the time–that a thirty-year cooling trend might continue and develop into a real ice age. The article was published on April 28, 1975, and attracted enough attention that other publications picked up the story with their own articles. Books and TV shows followed.

Scientific American, my source for this particular story, explains that the cooling trend is

now believed to be a consequence of soot and aerosols that offered a partial shield to the earth as well as the gradual retreat of an abnormally warm interlude.

And that

there also was a small but growing counter-theory that carbon dioxide and other pollutants accompanying the Industrial Age were creating a warming belt in the atmosphere, and by about 1980 it was clear that the earth’s average temperature was headed upward.

Scientific American acknowledges that the global cooling thing has no legitimate place in the climate discussion today, and reports that Mr. Gwynne himself is somewhat embarrassed by the anti-scientific uses to which his writing is being put. He does stand by what he wrote, given the limits of available knowledge at the time.

Ok, but there are a couple of problems with that story, starting with the fact that the greenhouse effect was not a “small but growing counter-theory” in the 1970’s–the effect of carbon dioxide on the climate has been known since 1859. The first calculations of the human role in climate change were made in 1896.

And it’s not like global warming was some far-out thing nobody was paying attention to back in the 1970’s, either. No less a person than the fiction writer, Ursula K. LeGuin had started making oblique references to climate change as early as 1969 (her novel, The Left Hand of Darkness, includes a flawless description of the natural greenhouse effect, as well as a reference to an alien planet that is hot because “an exploitive civilization wrecked its natural balances, burned up the forests for kindling, as it were.” Several of her later books also refer to the Earth itself getting warmer, too). Perhaps more starkly, the 1970’s were when Exxon was busy figuring out what it was going to do about global warming, of which its internal documents prove it was well aware.

Beyond all that, there wasn’t a 30-year cooling trend, except perhaps in a mathematical sense. According to the National Oceanic and Atmospheric Administration (NOAA), the period from the mid-1940’s to the mid-1970’s was cooler than previous years had been, but there was a lot of minor temperature fluctuation, not a consistent cooling. A cool period of relative stability is not the same thing as an oncoming ice age.

So, I did some more poking and found the second story.

Apparently, in the 1970’s, the greenhouse effect was well-known, but the cooling effect of sulfate emissions (“aerosols”) had just been discovered and it wasn’t clear yet which would prove dominant. A few climate scientists thought the aerosols might win out–between 1965 and 1979, 10% of the scientific papers on the subject predicted cooling, but 28% could make no prediction and 62% predicted warming. In other words, the coming ice age was a legitimate scientific idea for a while, but only a small minority of studies ever supported it.

I’m not actually sure, based on what I’ve read, whether anybody ever proved that sulfate emissions couldn’t have counteracted carbon emissions under some scenarios that were plausible back then. As history has actually played out, sulfate emissions have been dramatically reduced (they also cause acid rain), while carbon emissions have continued to climb. Aerosols still complicate climate predictions, but no one thinks they’re going to cause an ice age anymore.

There’s no cooling trend mentioned in there.

The way I see these two stories blending, I suspect that what really happened was that the end of the warming trend of the first third of the 20th century was taken (maybe correctly) as evidence of the cooling power of aerosols. Some climate scientists thought the aerosols could go on to trigger a cooling trend, but most did not. Peter Gwynne, being a writer who cared about science and about getting his writing published, chose to focus on the minority opinion, since that seemed more sensational at the time. He has admitted that the story “pushed the envelope a little bit,” in deference to Newsweek’s penchant for what Scientific American called an “over-ventilated style.”

The ventilation would have seemed harmless at the time, if the article was fundamentally accurate, as I’m willing to buy that it was. Nobody can represent the entire breadth of the scientific conversation on any one topic in just nine paragraphs. You have to choose which of all possible stories you’re going to tell, in order to tell any story at all.

That deniers have since pounced on his article for political and anti-scientific purposes is not Mr. Gwynne’s doing. Being co-opted is a risk all published writers run–it’s the Scylla to the charybdis of being utterly ignored.

Curiously, the one detail I thought would enter the discussion apparently didn’t, except as a note of context written long after the fact by one or another of my sources–astronomically speaking, we’re supposed to be in an ice age already.

The primary factor that dictated the glacial/interglacial cycle through recent geological history was the Milankovitch Cycle, an interaction between three separate variations in Earth’s orbit that together dramatically how much solar radiation we get at different times of the year. We’re at a point in the cycle where we should be heading into a new ice age, but aren’t because our carbon dioxide levels are too high.

The connection between that cycle and climate was confirmed in 1976, so it may be another thread of the “global cooling” story that none of my sources happened to tease out–but if not, there may have been good reason to ignore it.

The onset of ice ages is very slow. I have to cite one of my grad school classes here (Tom Wessels was the teacher–I’ve cited him as a source here before) as I haven’t been able to lay my hands on an appropriate link, but ice ages melt quickly (as in many hundreds of years) and grow slowly (as in many thousands of years). In fact, the warmest point of our current interglacial (before now, anyway) was thousands of years ago. No, the cooling was never enough to initiate continental glaciation on North America or Asia, but cooling was in progress.There is an excellent illustration of this cooling, and how long and consistent it was, here (yes, that is a web comic, but this one’s not a joke).

Sliding towards an ice age doesn’t look like anything special, it turns out. More or less, it looks like all of human history.