Thursday, November 28, 2019
Avoiding the Coming Ice Age
Cyclical phenomena are the easiest to predict accurately. The prediction industry got its start many thousands of years ago, when priests and shamans started gazing up at the stars and the planets and lining up rocks to sight them in. They used the information they gained through their stargazing to accurately predict the best times to plant crops or go fishing. People were duly impressed by such feats and thought that this was some sort of magic. Sometimes they stayed impressed for thousands of years. In Ancient Egypt, for instance, they believed that the Nile wouldn’t flood and irrigate their fields unless the Pharaoh performed his rituals and mated with his sister to produce the next Pharaoh. That, by the way, is called “magical thinking,” and in some ways it continues to this day. In the United States, for instance, people believe that if the Federal Reserve chairman continues to perform his rituals their country won’t default on its debt and the money will flow forever.
Perfectly cyclical phenomena are dead easy to predict if you know what to look for, but aside from celestial phenomena there aren’t too many of these. Semi-cyclical phenomena are far more common; in these, cycles are apparent, but there is also a lot of variability and chaos. Accurate predictions can be made here too—except with regard to timing. For instance, over a decade ago I bravely predicted that the United States empire will collapse at some point (because all empires collapse eventually—no exceptions!) but I demurred on making predictions about the timing of its collapse. I have been tracking its progression toward collapse ever since, with good results. At this point, I am tempted to go out on a limb and predict that if all goes well (for me) I will still be alive when this collapse actually transpires. When it does, I will no doubt be insufferably smug for a brief period of time, but then I will have to move on to predicting other things because predictions are only interesting if they are about the future, whereas predictions about the past are boring as shit.
Predictions about the remote future are boring as shit too. Astrophysicists predict that in a billion years or more our sun will bloat out to beyond Earth’s orbit and burn us up. This is, of course, highly irrelevant to us, since mammalian species like ours go extinct after just a few million years. Our species in particular tends to run a much higher risk of extinction whenever there is an ice age. During these times small groups of fur-clad people sit around in dank caves (where it’s warmer) burning bones to keep warm and gnawing on carcasses. Ice ages occur quite regularly, last for tens of thousands of years, and during these times human populations dwindle to almost nothing. Based on historical evidence, we can bravely predict that another ice age is just around the corner and may start any century now. Since this particular prediction about the future also fails to thrill, let’s try going back to making predictions about the past.
One type of prediction about the past is currently considered quite exciting. This prediction is made on the basis of climate models: computer programs that simulate Earth’s climate based on scientific theories about how climate works and various types of indirect evidence such as tree rings and ice and sediment cores. They are considered more trustworthy than, say, tea leaves or goat entrails because they are back-validated: their predictions about the future are assumed to be accurate because of the accuracy of their predictions about the past. They are tweaked until they match historical data by messing with various fudge factors. Then, based on a gigantic leap of faith, they are imputed to be able to see into the future. This imputation rests on the seldom discussed assumption that climate is predictable rather than chaotic.
Climate does seem rather chaotic, at least in the short run (centuries and millennia). There was a cooling episode that coincided with the collapse of the Western Roman Empire. Then there was a warming episode during which Slavic tribes proliferated throughout Eastern Europe and farmed the land all the way up to the Arctic Circle. During that same period, the population of pastoral nomads throughout the Eurasian steppe exploded. Eventually it organized around the Mongols led by Genghis Khan and created an empire that at one point included most of Eurasia, including China, Russia, India and Persia, and Eastern Europe up to the gates of Vienna. This was followed by a cold spell during which the Mongol Empire collapsed. Information on what exactly happened is sketchy because reliable data are scarce and explanations of why these climatic shifts happened when they did are sketchier still. When it comes to climatology, the past is a bit murky but the future is bright as can be.
This is all very interesting, but there is a key point that needs to be made: predictions based on climate models have not been validated through observation. Sure, they can be back-validated against historical data, but that’s just scientific trickery. If you want to make a stock broker laugh, tell him that you have a computer program that accurately predicts last week’s stock prices. We have to wait a few centuries to find out whether the predictions made based on climate models will have been accurate. In the meantime, a bit of skepticism with regard to these predictions seems quite in order. Predictions that have not been validated through subsequent observation cannot be treated as “settled science”—by definition. They are purely theoretical. So far, we have approximately 1ºC of warning since what is assumed to be “average global pre-industrial temperature” which was never measured directly. This amount of warning is neither here nor there. During the Paleocene-Eocene Thermal Maximum, which was around 55.5 million years ago, global average temperatures are said to have been as much as 14ºC warmer than today.
Since the science is still out on the extent of future global temperature rise (due to lack of time to make the observations necessary to validate the theory) we have to assume that what we are dealing with is not science but a science-based cult. Indeed, the amount of emotionalism currently displayed with regard to what the thermometer has to say is very much out of character for anyone involved in any sort of scientific endeavor and is more indicative of some sort of religious experience. There is also a nasty political angle to the overwrought and overheated rhetoric concerning global warming: developed nations, which have already squandered their endowments of fossil fuels and are therefore no longer developing, may be suspected of using climate science-based moralizing to thwart the efforts of developing nations to catch up with and overtake them. This, mind you, isn’t working at all—a fact that may explain the otherwise inexplicable hysterics elicited by a 1ºC global average temperature rise.
Since this is the case, we should feel it justified to engage in some meta-theorizing: forming political and sociological theories about climate theories. Especially interesting are those that we can test. One particular hypothesis is that climate theories that predict global warming are more likely to be popular than those that predict nothing particularly dramatic or don’t predict anything at all, and that theories that predict very dramatic global warming are likely to be even more popular. We can verify these predictions using AB testing, which is extensively used in advertising. Suppose you run an ad agency, and you have a designer who wants to add squiggly lines to an ad and an account exec who hates squiggly lines. You can resolve this dilemma by running ads with squiggly lines (A) and without (B) in different but similar markets and finding out which ones work better based on their effect on sales.
I believe that such AB testing of climate theories will definitively show that people will prefer theories that confidently predict global warming and associated calamities rather than those that predict more of the same or don’t predict anything in particular. But such testing may not even be necessary. Back in the 1970s climate theory predicted that the next ice age could start any year now, but that theory fell by the wayside some time ago. It just didn’t catch the public imagination the same way as global warming. Ice Ages is kid’s stuff about an acorn-obsessed squirrel named Scrat, whereas global warming is an adult, heroic genre that includes Mad Max and Waterworld. Interminable ice ages are a hard sell; nobody really wants to sit through hours of watching fur-clad hairy people trying to kill animals with pointed sticks, then huddling around a fire gnawing on bones.
Climate scientists clearly got the message that global warming is in and ice age is out, and have been behaving accordingly. We can readily observe people throwing around terms such as “scientific opinion” and “scientific consensus” on global warming, and some even call the evidence of catastrophic climate change “overwhelming.” Note, however, that in science opinion is not even a thing. Nor is scientific fashion. What makes science science is the use of the scientific method. Scientists develop theories, use these theories to make predictions, design experiments to test these predictions, run the experiments and observe the results. If the results match the predictions, the theory remains; if not, it is discarded no matter how fashionable it happens to have been. With regard to climate change the experiment hasn’t been run yet (since this would take a few centuries at least) so all we have is theory and some fashionable but untested predictions.
Nevertheless, lots of people right now are quite emotional about global warming predictions that are based on untested computer climate models. Some are advocating taking drastic steps to try to stop it—cutting carbon dioxide emissions, mostly. Notably, people have been advocating taking such steps for decades now, with negative results. But there is good news for them: easy-to-access fossil fuel resources are dwindling fast, and although overall fossil hydrocarbon reserves are, for all intents and purposes, limitless, the quantities of them that can still be produced profitably are rather limited; to wit, shale oil and gas in the US has been a net waste of money. Most countries are already past their peak as fossil fuel producers. This is good news if you see global warming as a problem and bad news if you see it as the solution to an even bigger problem, which is its opposite: global cooling, to be followed by global freezing.
On the time scale of decades and centuries climate seems rather chaotic, but if you zoom out to the time scale of millennia and farther out then a semi-cyclical pattern becomes obvious. There are indications that the cycles are related to fluctuations in solar radiation and Earth’s orbit, but what’s interesting is not what gives rise to this pattern but what it means as far as the future climate. Given all the attention given to global warming, it may surprise you to learn that Earth is currently in an ice age—and has been for the past 2.6 million years. Antarctica is covered by an average of 2000m of ice; Greenland’s is similar. Permafrost covers 22.8 million km2 of the Northern Hemisphere; that’s roughly $23 trillion worth of farmland (at current average US prices) that can’t be farmed because it’s too cold. (Incidentally, that is also the size of the US federal debt.)
In the chart below, interglacial periods are marked in green. Note that they have been rather short relative to the ice ages, and that our current one is quite a lot longer than all the others.
Earth hasn’t always been this cold. The warmest recent period was between 60 and 100 million years ago, when average global temperatures were 10ºC warmer, there was very little ice everywhere, Sahara was lush and forested and alligators frolicked in the Arctic. Had humans existed at the time, they would have had a fun time hunting dinosaurs up in the Arctic. Global temperatures have been dropping ever since, with a sequence of long ice ages interrupted by much shorter warmer periods. The current warm spell, running for some 10 to 12 thousand years now, is uncharacteristically long, and we are due for another ice age any century now. This should be rather alarming news for the millions of people who live in places that will end up permanently frozen and eventually crushed by advancing glaciers.
Luckily, there is something we can do to push off the next age by at least half a million years: burn more fossil fuels. According to some calculations, the amount of fossil fuels burned to date is nowhere near sufficient; to get the desired effect, we would have to triple that amount. In the chart below, the upper red squiggly line models the effect of tripling atmospheric carbon dioxide from its current levels, bravely predicting that doing so will safely keep out of an ice age for the next half a million years at least, which may perhaps be long enough for humans to go extinct as all mammals do eventually.
The only fossil fuel source that is sufficiently abundant is coal. As a source of carbon dioxide emissions, coal is quite potent, being three times more effective per unit energy than natural gas. Unfortunately, there may not be enough accessible coal left, and most of the remaining coal reserves are of rather poor quality: a lot of the best-quality anthracite, such as Welsh coal, has already been produced, and what’s left is much lower-quality lignite which is not as energy-dense. If enough coal can’t be found to ward off the next ice age, it may become necessary to resort to releasing as much methane as possible. Abundant quantities of methane exist in the form of oceanic clathrates, or methane ice, at great depths, and could be released, perhaps by periodically dropping small nuclear depth charges on the larger clathrate deposits. Methane is a very potent greenhouse gas—30 times more effective than carbon dioxide—but it doesn’t last as long in the atmosphere, and so this ocean nuking procedure would have to be repeated periodically.
Some people have voiced concerns that greenhouse gas emissions might trigger runaway global warming and cause Earth to become hot and lifeless like Venus. A bit of high school physics and math would go a long way toward dispelling this ridiculous myth. Distance from Sun to Venus is 108 million km while from Sun to Earth it is 149 million km. Solar radiation intensity varies as the inverse square of the distance and
149-2 / 108-2 ≅ 2
So, Venus gets twice as much energy from the sun as Earth. Meanwhile, average Earth temperature is 14.9ºC (58.85ºF) while on Venus it is 462ºC (863.6ºF). Relative to the temperature of outer space, which is 2.73º Kelvin, Earth is at 285.32ºK, Venus is at 722.42ºK and 725/288 ≅ 2.5. So, Venus is 25% warmer than it ought to be from just the solar radiation, and if Earth had a Venusian atmosphere it would perhaps be as hot as 356.65ºK or 83.5ºC (182.3ºF). But we shouldn’t be too quick to jump to conclusions that this is due to Venusian greenhouse effect because the specifics of Venus are rather different.
For one thing, Venus rotates sluggishly: Venusian day is 2802 hours long, meaning that the day side bakes in the sun for a really, really long time and should be much hotter than the night side. Yet that’s not the case: the two sides are at the same temperature, and the poles are as hot as the equator. For another, Venus is much more volcanically active, with giant lava fields, more volcanoes than any planet in the solar system and, most likely, frequent volcanic eruptions. Lastly, Venus is permanently shielded from the sun by thick cloud cover which reflects most of the sunlight.
And so the greenhouse effect may be a minor contributing factor to Venusian hothouse climate, but the real reason it’s so hot is not due to sunlight (most of which is reflected right back into space) but because it is a ball of molten rock. Thus, there is no reason to hyperventilate over the idea that greenhouse gas emissions could turn Earth into another Venus. People who have done far more detailed math on this question have concluded that no amount of greenhouse gas emissions will force Earth’s climate beyond what was achieved during the Paleocene-Eocene Thermal Maximum, during which alligators and hippos frolicked in the Arctic, Greenland was entirely green and Antarctica may have been forested.
Even if that were to happen, this would not necessarily spell the end of life on Earth. In spite of the ridiculous temperatures on the surface of Venus, Soviet Venera probes spotted some strange three-legged critters hobbling about its surface, leaving a trail of footprints in the dirt. Other Venusian critters were recorded emerging from under Venusian dirt, then reburying themselves. Yet other creatures didn’t move but had a consistent size and a distinctive oblong shape suggesting a head and a tail, with the tail that sported a chevron pattern. More research is obviously needed to find out what that’s all about, but the intriguing evidence that has been collected by these probes makes Venus rather interesting—more so than the permanently frozen, relatively airless wastelands of Mars. Since neither Mars nor Venus are the least bit suitable for human habitation, such exploration has been of no practical merit whatsoever, although the unique technology it has forced scientists and engineers to develop could have important applications here on Earth.
The plan to burn all the fossil fuels we can get our hands on to avoid having Earth descend into another ice age for half a million years could be a reasonable one—except for one nagging doubt. Looking at the temperature record for the past half a million years, the short warm interglacial periods all tend to come to a rather sudden end, and it seems plausible to think that the onset of an ice age is specifically triggered by a spike in global temperatures. How this might occur is as follows.
The most important substance on Earth, and one that influences just about everything, is water. Evaporation and atmospheric water vapor concentration increases as the temperature rises, roughly doubling for every 10ºC (20ºF) rise in temperature. As the globe warms, even by just a few degrees, atmospheric water vapor concentration rises dramatically. This can go on for quite some time, the weather getting hotter and muggier all the time. But then a volcanic eruption, an asteroid strike or a nuclear war puts a lot of fine aerosols in the stratosphere, and from there it circulates all over the planet, carried by the jet stream. The aerosols provide nucleation points for water vapor to condense around, forming thick, unbroken cloud cover that can persist for a long period of time. This cloud cover reflects enough solar radiation to significantly cool the surface of the planet—enough to cause snow and ice to persist year-round over a significant part of the surface, continuing to reflect sunlight even after the clouds dissipate. Over subsequent decades and centuries the snow pack accumulates, eventually forming glaciers over much of the northern hemisphere.
If this is what actually happens whenever a global warming episode collapses into the next ice age, then burning all the fossil fuels we can get our hands on, nuking oceanic clathrates or whatever else we might come up with to ward off the next ice age will not work. It would be most helpful if climate scientists moved past their media-driven obsession with global warming and looked into this question. As it is, global warming is becoming a bit of a hard sell, so climate scientists may want to diversify and get ready to jump on another bandwagon before the grant money stops flowing. The Chinese are building more coal-fired power plants than the entire EU currently has, global warming be damned. And don’t even try telling the good people of Verkhoyansk, Yakutia, Russia (population 1122), where it is currently –52ºC (–61ºF), that they ought to stop burning so much coal because the entire planet is getting too warm for someone’s personal taste.
Ice age avoidance seems like a wonderful new priority. Climate scientists will still get to scare the shit out of everyone—enough to keep the grant money flowing—plus they’ll make themselves popular with all the people who are currently shivering from the cold and are finding their global warming message unimpressive. Of course, this is just a prediction based on my personal theory, so they should try AB testing it first.