Every year or two on this blog I post an update on the global climate. Now and then I wonder if this is a futile effort. Outside the four notional walls of this one little blog on the fringe, and a few other equally marginal venues, the rest of the world seems to be caught up in a debate about the climate that permits two and only two viewpoints. On the one side you have the people who insist that global climate change is an apocalyptic horror that will surely kill us all unless we kowtow to an increasingly baroque and intrusive set of rules that they themselves aren’t willing to follow. On the other side you have the people who insist that global climate change isn’t happening at all. They’re both wrong, but that hardly matters: with every failed prediction—and both sides have made a good many of these—the shrieking from the true believers just gets louder, drowning out the few voices of moderation in between.
Then the moment passes, and perspective returns. One of the great lessons of history is that there really are limits to how long you can talk people into disbelieving the evidence of their own senses. To cite only one example, all those supposedly authoritative claims that the vaccines would keep you from catching or transmitting the Covid virus didn’t keep people from noticing that the vaccines did neither of these things, which is one of several reasons why attempts to push yet another round of Covid vaccines on the public are doing so poorly. In the same way, the rhetoric on both sides of the climate change issue is losing its appeal as people notice that the climate really is changing, but the predicted apocalypse keeps on pulling a no-show.
It’s crucial to remember that the future of global climate does not depend on what people say. (You’d think that the vast amounts of hot air vented by all sides in the dispute would have some effect on the climate, but apparently not.) The future of global climate also doesn’t depend on what the scientific consensus says it is; if the history of science teaches anything, it’s that when there’s a scientific consensus—which is by no means that common—it’s wrong at least as often as it’s right. The future of global climate depends not on any of these things, but on an immensely complex network of feedback loops and planetary processes that are very poorly understood at present, and may be wholly beyond our ability to measure or calculate. There’s a useful source of data that can help us understand where the global climate might be headed, but—well, we’ll talk about that a little later in this post.
Let’s start by setting aside the rhetoric from both sides and talking about what’s actually happening in the world. The most important change in global climate over the last few decades has been the gradual shifting of climate zones away from the equator. If you live in the US and notice the USDA climate zones, you already know all about this, because many localities here are a zone or two warmer than they were in the mid-twentieth century. Those zones aren’t arbitrary; they’re determined by hard quantitative measurements such as the number of days between the last frost in the spring and the first frost in the fall—and they’re on the march.
The eastern half or so of the United States is lucky, because the changes in climate it’s getting mostly mean less snow to shovel in the winter and a longer growing season in backyard gardens. Russia’s even luckier, because the changes in the length of the growing season there gave it the biggest wheat crop on record last year, and this year’s is shaping up to be even bigger. Other parts of the world are not so fortunate. Large parts of southern Europe are seeing the same northward shift of climate belts, and what’s directly south of them is the Sahara Desert. The same thing is happening in the western half of North America, where the Sonoran desert of northern Mexico is moving in. In all these cases, the shift is gradual, and it’s interrupted at times by turbulent weather—that’s why, as I write this, the people at Burning Man are squelching around in three inches of mud, courtesy of unseasonable rains—but the trend is there.
At the same time the oceans are behaving oddly. The corporate media spent some time fussing earlier this year when quite a bit of the North Atlantic was a degree or two warmer than usual. That’s a significant event, all the more so because scientists admitted that they had no idea what was causing it. (Of course it was attributed to climate change anyway.) If you were paying attention, you may have noticed something else odd about the summer just past: the first half of the Atlantic hurricane season was a damp squib, with a flurry of short-lived tropical depressions and weak storms that went nowhere. Was some of the heat that usually feeds hurricanes in the central Atlantic finding its way to the poles instead? It certainly looks that way.
Meanwhile glaciers are melting over much of the world. That’s not a new thing—glaciers are very rarely static, they’re usually either growing or shrinking depending on the balance between gains from each winter’s snowfall and losses from each summer’s melting—but the continental glaciers of Greenland and Antarctica, which contain most of the planet’s ice, are melting at a faster rate than usual. Right now that’s causing a few millimeters a year of sea level rise; the world’s oceans are vast enough that it takes an astounding amount of melting ice to raise their level noticeably. If things follow their current trajectory, though, we could get a steady couple of inches a year by the end of the century: enough, extended over decades, to flood low-lying districts and force the relocation of seaports at gargantuan cost.
All this is part of a broader picture. In global terms, the summer just ending was the hottest ever recorded—that is to say, the hottest we’ve had since accurate thermometers were invented, which admittedly didn’t happen all that long ago. As usual, most of the increase in temperature was near the poles. There were some notable bursts of heat in the tropics as well, but around the Arctic Ocean is where the real action is happening, with unseasonably warm days occurring so often that the word “unseasonable” is going to have to be retired soon. Permafrost is melting and some amount of extra methane is bubbling up into the sky, where it will add a boost to warming for a while before it breaks down. (Methane doesn’t last long in an oxygen-rich atmosphere.)
So the climate is changing, but the apocalyptic events predicted so loudly by the corporate media and privileged activists of the Greta Thunberg type are still hanging in the same limbo as the “winter of sickness and death” Joe Biden promised the unvaccinated a couple of years ago. Those of my readers who’ve been following my blogs long enough will doubtless recall the comparable trajectory followed by peak oil a decade ago. One group of people insisted at the top of their lungs that the world’s oil supply really was infinite, or that some other energy resource would surely step in just in time to pick up the slack, while another proclaimed just as loudly that the apocalypse was on us and someday very soon the few survivors would be creeping out of burnt-out basements to piece together a subsistence economy. It’s the same drivel eternally.
As we all know, what the peaking of conventional petroleum production in 2005 actually brought was a long slow struggle with rising prices and economic instability—a struggle that’s far from finished in 2023, and won’t be over yet when 2123 rolls around, either. Compare the climate change rhetoric from both sides with what’s actually happening, and it’s pretty clear that a similar dynamic is playing out there. Slow, ragged changes spread out across centuries don’t play well in disaster movies, or in the kind of overheated activist rhetoric that makes Sharknado sound realistic. Nonetheless, that’s what’s happening, and it might be a good idea to set aside the sticky-fingered fantasies of apocalypse and pay attention to the facts on the ground.
It’s at this point, too, that it makes sense to bring in the useful source of data I mentioned earlier: the evidence from climate change in prehistory. There’s a lot of that—paleoclimatology has been a lively field for many years now—and it has a lot to say to our current situation. Of course the moment I bring up evidence from the past, dear reader, you know just as well as I do that some earnest but inadequately educated activist or other is going to trot out the standard-issue thoughtstopper: “But nothing like this has ever happened before!”
That’s a very fashionable claim. It’s also wrong, and not just a little bit wrong, either. The people who make it are displaying an embarrassing ignorance about the most basic facts of prehistory. To begin with, the Earth’s climate is anything but stable. Twenty thousand years ago, an eyeblink in geological time, the Earth was much colder than she is today; that’s why the pleasant corner of Rhode Island where I live was under a mile of ice then. Go back another hundred thousand years, and the Earth was much warmer; at that time Rhode Island had roughly the same climate North Carolina has today. Go back further, before the great cooling trend of the Neogene period, and the Earth was warmer still—think palm trees and crocodiles on Rhode Island’s shores.
Nor are sudden climate changes anything new. Some of them, in fact, were much more sudden and drastic than the one we’re currently in. The heat spike around 9600 BC is a good example, not least because it’s recent enough that there’s good ice core data, allowing the speed of the change to be measured much more closely than other forms of data will allow. At that time—my source here, in case you want to look it up for yourself, is Steven Mithen’s widely praised book on postglacial times, After the Ice—Earth’s average temperature jolted up 7° C in less than a decade. Nobody’s yet sure how that happened, though there are some plausible theories. The point to notice is that not even the most extreme climate theories right now are predicting a 7° C increase in global temperature over the next decade. Difficult as the current situation promises to be, it’s well within the normal variability of Earth’s climate.
So climate change has happened before, and very fast climate change has also happened before. It’s when we go beyond this and talk in more detail about what a warmer world is like that things begin to get very, very strange. It so happens, to begin with, that the Earth is usually much warmer than she is today. Cold spells like the one that shapes our current biosphere happen at long intervals, but they’re the exception, not the rule. Under more usual conditions—well, here’s how a Harvard University website puts it: “the temperature was roughly equal everywhere in the world. In the past, this state existed because the poles were significantly warmer than they are currently, while the Tropics remained at roughly present day temperatures.”
The technical term for this is an equable climate. When the Earth has an equable climate, the equator to pole temperature difference (EPTD) is much lower than it is now, and the seasonality—the temperature variation from summer to winter—is also much lower. Fifty million years ago, during a recent era of equable climate, sea surface temperatures in the Arctic Ocean were in the subtropical range, between 64° and 77°F, and crocodiles sunned themselves on the beaches of northern Greenland: yes, their fossils have been found. North Dakota in the winter never had freezing temperatures for as much as 24 hours at a stretch. In Antarctica, palm trees grew and frost was a rare event. In effect, the tropics extended north and south from the equator much further than they do now, and subtropical conditions extended from there to the poles.
It was a very different world. The only glaciers were on high mountains close to the poles. The only deserts were in the rain shadows of tall mountain ranges. Snow was a rarity away from mountain summits. The Sahara and the Arabian peninsula? Green and fertile, watered with regular rains. The world was wrapped in a springtime that lasted for millions of years.
There are good thermodynamic reasons why this should be the case, though the Harvard website linked above and the other literature on equable climates I’ve read don’t mention that. The Earth’s atmosphere, from a thermodynamic perspective, is a heat engine. When you add more insulation to a heat engine, it runs more efficiently and does more work: that was James Watt’s great discovery, the insight that made steam engines economically viable and launched the industrial revolution. Greenhouse gases in the atmosphere provide insulation—and one of the kinds of work the atmospheric heat engine does is pump heat from the equator to the poles. Right now the heat engine over our heads is running very inefficiently, which is why so little heat makes it all the way to the poles. When it’s running more smoothly, things are different.
The kind of permanent springtime we’ve just discussed isn’t a rarity; it’s Earth’s normal climate. During the last hundred million years or so, the Earth has had an equable climate roughly two-thirds of the time. The global climate has only been like it is today, with high EPTD and high temperate and polar seasonality, for a very small portion of the remainder. All of this is very well discussed in the literature; if you go to the Harvard site linked above and click through to the page of references, you’ll find an ample supply of peer-reviewed articles from respected journals of paleontology and paleobotany documenting every claim I’ve made here. You might want to go download a copy of the references list soon, though, because it wouldn’t surprise me at all if the entire website gets taken down in a hurry once Harvard notices that somebody outside the scientific community has read it and drawn the logical conclusions.
I mean this quite literally. The entire debate on climate change has displayed a weird astigmatism of the imagination that can be seen in plenty of other debates. The notion seems to be that present conditions are the best of all possible worlds and any change must be a dreadful catastrophe. You can see the same thing in the political sphere, where all sides spend all their time talking about how the other guys are going to make things worse and nobody ever seems to think of suggesting ways to make things better. You see it in the bizarre rhetoric around “invasive species”—that is, living things that do what living things always do, and expand their range into ecosystems where they might thrive. Remarkably large numbers of people seem unable to respond to the presence of such newcomers—provided they’re not human, of course—except by declaring all-out war.
It’s really strange. Our society worships the concept of progress, and insists loudly that change is good and newer must be better, even (or especially) when it’s not. At the same time, the thought that the climate might change, or that the distribution of living things might change, or that some details of our political and economic arrangements might change in ways that are more than cosmetic—that calls up atavistic terrors, and drives frantic (if usually ineffective) action to ward off the threat that things might be different. For that matter, have you noticed how often the villains of our fantasy novels and superhero movies are out to change things, and how often the heroes have no other goal than making sure that everything stays the way it is?
Please note, however, that I’m not suggesting that we all run out and burn as much fossil fuels as we possibly can, in the hope of restoring the Earth to her normal temperature range. To begin with, nobody knows exactly why the Earth’s climate is usually equable, or what changed to plop us into our present cold snap. Granted, there was much more carbon dioxide in the atmosphere during the last era of equable climate than there is now, but was that all there was to it? Nobody knows. The Earth’s atmosphere is far more complex than our current models can handle. Trying to tinker with it in our present state of very partial knowledge is akin to handing an energetic six-year-old a set of tools and having him get under the hood of your car.
Second, an equable climate may sound great in the abstract, but getting there’s not going to be so fun. To begin with, melting the polar ice caps will raise sea levels three hundred feet. While it will take centuries for this process to complete, even the first steps along that route will play merry hob with the global economy, flooding most of the world’s large cities and a vast amount of other real estate, erasing entire nations from the map, forcing mass migrations, crippling ports and other trade facilities, and the list goes on. Meanwhile the weather isn’t simply going to pop right into an equable condition; to judge from what’s currently happening, the climate belts will keep on lurching unsteadily toward the poles a little at a time, causing droughts, floods, famines, and other entertainments. A thousand years from now things may be great, but that’ll be small consolation to you, or to the generations who have to deal with the rest of the change.
But there’s another reason why we don’t need the kind of homegrown geoeingineering project described above: it’s superfluous. There’s no shortage of people already hard at work on it—and a remarkably large number of them insist that they care about the climate and are trying to fight climate change. Most people these days know all about the fleets of private jets that take the rich to and from the World Economic Forum meeting at Davos and similar venues for climate change pontification. Quite a few people have witnessed the smaller-scale equivalent, the millions of earnest people in the comfortable classes who insist that they care about the fate of the Earth, but never take that to the point of cutting their own carbon footprint to any noticeable extent, and who typically use far more than their share of fossil fuels and their direct and indirect products.
Protest marches and virtue signaling do nothing to keep the resulting carbon dioxide out of the atmosphere. Nor do the wind farms, rooftop solar panels, and other pork barrel projects that have been marketed so heavily using climate change as a sales pitch Nor, for that matter, do any of the other gimmicks that have been so heavily promoted and praised by corporate media. If you doubt this, dear reader, take a good look at the chart of carbon dioxide levels in the atmosphere, and see if you can find any sign that any of these things have slowed the steady increase in carbon dioxide one iota. If the point of the last three decades of climate change activism was to slow the rate at which greenhouse gases enter the atmosphere, the results are in and the activists have failed. Nor is there any reason to think that doing more of the same will yield anything else; what’s that saying about doing the same thing and expecting different results?
That being the case, barring a sudden change of heart among the comfortable classes that leads them to take their claimed beliefs seriously for a change, and cut their own carbon footprint, instead of hogging as much as they can and shrieking about how everyone else has to cut back, we’re on our way to wherever global climate change is taking us. Like so many other aspects of our present predicament, climate change is like a toboggan ride. If you want to do something other than hurtle down the slope, you need to make changes as soon as possible; once you pick up speed, all you can do is hang on tight and see where you end up.
A good case can be made, I think, that we’re on the climate toboggan now. Where we’ll end up is a fascinating question, though it’s one that only our descendants will be able to answer. One way or another, though, I expect a bumpy ride.