How to measure an apocalypse
So… how much trouble are we in?
This went to paying subscribers back in January but, given the week’s British political news, felt oddly relevant right now. Want to make sure you’re not missing anything? You know what to do:
I recently read my occasional co-author Tom Phillips’ book A Brief History of the End of the F*cking World, which tells the story of the apocalypse from the original Armageddon (the battle of Megiddo, fought between Pharaoh Thutmose III and assorted vassal states in the 15th century BCE) to the exciting range of things that may actually kill us all today (pandemics, climate change, A.I. and so forth). It’s great. If you liked Conspiracy: A History of B*llocks Theories, and How Not To Fall For Them, or really any books, you should buy it now.
Among the many things I learned from Tom’s book is that there are not one but two ways of quantifying the threat of humanity going the way of the dinosaurs – of a “Near-Earth Object”, like an asteroid or a comet, ceasing to be near the earth and becoming instead part of it, at great speed, bringing fire, blastwave, nuclear winter and so forth along with it.
One of these is the Palermo Technical Impact Hazard Scale, which combines probability of impact with estimated kinetic yield into a single rating, and of which, if I’m honest, I can’t make head nor tail. When I wrote this(Wikipedia: “No asteroid has a cumulative rating for impacts above 0, and only two asteroids have ratings between −2 and 0.” Got that? Me neither.)
The other is the Torino Scale (“Planetary scientists like having conferences in Italy,” notes Tom), which uses a rather more intuitive numbering system running from 0 (“The likelihood of a collision is zero, or is so low as to be effectively zero”) to 10 (“A collision is certain, capable of causing global catastrophes that may threaten the future of civilization and life as we know it”). In between, the scale moves through a series of colour-coded steps rated as “normal” (1; green), “meriting attention by astronomers” (2-4; yellow), “threatening” (5-7; orange) or “certain collison” (8-10; red).
Things only start getting hairy at level 4: “A close encounter, meriting attention by astronomers. Current calculations give a 1% or greater chance of collision capable of regional devastation”. (No good news ever includes the word “devastation”, does it?) In the 30 years since Professor Richard P. Binzel of MIT came up with the scale, only one object – 99942 Apophis, an asteroid 370m in diameter – has ever been rated that high on the scale, and then for only four days back in 2004. It’s since been removed from the risk-list altogether, even though it’ll be passing within 40,000km of the Earth on 13 April 2029.
When I originally published this piece, the next sentence was, “Only one other asteroid has ever made it past Level 1”. That, in a manner which makes me worry I’m actually in a simulation of some kind, changed that literal day when news broke that asteroid 2024 YR4 had been given a rating of 3. (Slightly less than four weeks later, it had thankfully been downgraded again.) In my defence, it was inevitable that there would be more worrying asteroids eventually – I just hadn’t expected it to be quite that soon, or for it to turn out that I had the power to conjure them into existence purely by sneering.
Luckily – from a content point of view, if not a continuing existence one – there are plenty of other types of disaster that clever people have attempted to quantify. I’ve been familiar with the Beaufort wind force scale and its oddly poetic language for conditions at sea and at land, since childhood (“6: Strong breeze. Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty”). The lower levels (“1: Light air. At sea, ripples with appearance of scales are formed without foam crests”) are obviously not actually disasters, but then neither is a Level 1 on the Torino Scale. The upper levels (“12: Hurricane-force. At land, devastation”) are a different matter entirely. In special cases, like tropical cyclones, the scale actually goes up to 17. It is perhaps for the best that we do not have those here.
Then there’s the Richter Scale, a logarithmic scale for the magnitude of earthquakes. I’m not going to dwell here because it’s the most familiar of the true disaster scales. I will merely note that the claim that a moderate earthquake in the 5.0-5.9 range should be “felt by everyone” is not true, if only because last summer in Lisbon I managed to sleep through one.
Then there’s the volcanic explosivity index (VEI), which uses volume of products, eruption cloud height and qualitative observations to classify volcano eruptions:
Those “qualitative observations” are worth dwelling on for a moment. They are, in ascending order of destructive power: effusive, gentle, explosive, severe, catastrophic, cataclysmic, colossal, super-colossal and mega-colossal. Overlapping that, but not with a one-to-one correlation, are the volcano “classifications”: Hawaiian, Strombolian, Vulcanian, Peléan, Sub-Plinian, Plinian and Ultra-Plinian. Don’t ask me, I just like the words.
There are a variety of tsunami intensity scales, too, which measure tsunamis based on wave height, flow depth and impact on people and property. There’s the Enhanced Fujita Scale, which measures tornadoes, based on speed and damage, and whose Wikipedia page helpfully includes inadvertently hilarious pictures of the latter to illustrate each rank of tornado.
And there’s the Interaction Nuclear and Radiological Event Scale, which like the Richter scale is logarithmic, and which runs from 0 (deviation) to 7 (major accident). At that top level, you’re looking at a “major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures” – and this, unlike the top rank of some of these scales, has actually happened. Twice. You can probably name both incidents: the Chernobyl disaster in Ukraine, on 26 April 1986; and the Fukushima disaster in Japan, on 11 March 2011.
The latter, incidentally, was caused by an earthquake, a reminder that one disaster can easily lead to another. At a human level, the exact nature of the thing that just demolished your house and destroyed your family matters rather less than the fact it happened at all.
So, attempts have been made to come up with a universal scale. There’s the Rohm emergency scale, which looks at fatality numbers, monetary losses, geographic scale and so on to create a mathematical model that is, quite frankly, entirely incomprehensible to me.
But I did enjoy, if that’s the word, browsing this paper from the journal Natural Hazards, part of an “ongoing research project to develop a multidimensional Universal Disaster Severity Classification Scheme to understand the disaster continuum”. It spends a long time debating the finer points of such a model, trying to decide whether a calamity is worse than a catastrophe and so forth, before producing this weirdly pleasing diagram of horrible things that can happen to people:
The upper levels, thankfully, have not happened in human history.
Yet
.
Anyway, buy Tom’s book.