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Top Comments: Hollow Scene Edition
We live in an entirely new geological epoch, at once defined by the retreat of the icecaps from the last glacial episode and by the geophysical impact of Humanity on the life, the climate and the body of the Earth itself. This period has a name the Holocene:
I prefer to call it the Technozoic, but I think the impact of Humanity of rock strata would have to raise its game a notch or two (an ambition which might be fulfilled by, oh, irradiating the crust with plutonium, transmuting everything to a depth of 100 kilometers into computronium, or supersaturating the crust with utility sand to bring up useful materials (from water to iron to lithium to chewy hydrocarbons) to qualify for that lofty title.
The Holocene is a geological epoch which began at the end of the Pleistocene (around 12,000 to 11,500 14C years ago) and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words ὅλος (holos, whole or entire) and καινός (kainos, new), meaning "entirely recent". It has been identified with the current warm period, known as MIS 1 and based on that past evidence, can be considered an interglacial in the current ice age.
The Holocene also encompasses within it the growth and impacts of the human species world-wide, including all its written history and overall significant transition toward urban living in the present. Given these, a new term Anthropocene, is specifically proposed and used informally for the latest part of this epoch since approximately synchronous lithospheric evidence, or more recently atmospheric evidence, of human impacts have been found on the Earth and its ecosystems; these impacts may be considered of global significance for future evolution of living species.
Well…there is one conspicuous way we’ve modified the soil of the Earth: We’ve turned much of it into a mass grave for our fellow species.
In honor of that dishonorable streak of misdeeds, perhaps we should rename our era the Hollow Scene, though the current moniker is more clinical: The Holocene Mass Extinction:
It would be nice to say these die-offs are coincidental with the rise of humanity’s numbers. Oh, noes. It’s the Ice Age! All those passenger pigeons and dodos and temperate and tropical species are extinct because it stopped being cold! Oh, wait…
The Holocene extinction is the extinction of species during the present Holocene epoch (since around 10,000 BC). The large number of extinctions span numerous families of plants and animals including mammals, birds, amphibians, reptiles and arthropods. Although 875 extinctions occurring between 1500 and 2009 have been documented by the International Union for Conservation of Nature and Natural Resources, the vast majority are undocumented. According to the species-area theory and based on upper-bound estimating, up to 140,000 species per year may be the present rate of extinction.
The Holocene extinction includes the disappearance of large mammals known as megafauna, starting between 9,000 and 13,000 years ago, the end of the last Ice Age. Such disappearances are considered to be results of climate change or the proliferation of modern humans, or both. These extinctions, occurring near the Pleistocene–Holocene boundary, are sometimes referred to as the Quaternary extinction event or Ice Age extinction. The Holocene extinction continues into the 21st century.
There is no general agreement on whether to consider more recent extinctions as a distinct event, merely part of the Quaternary extinction event, or just a result of natural evolution on a non-geologic scale of time. Only during these most recent parts of the extinction have plants also suffered large losses. Overall, the Holocene extinction can be characterized by humanity's presence.
It would be nice to say, hey, it’s a success metric. Yay, people… except we’re killing ourselves in the bargain. Oops.
Few are aware we are ending us by ending them. Worse, fewer still of this sparse number care.
They might care if they knew the full list of species likely to die by then end of the 21st Century. Oh, wait. They do know; here is the list of Critically Endangered Animal Species put out by the International Union for the Conservation of Nature.
They might care if they knew, if nothing gets any worse any faster than it is right now, how few thousands of years they have to get it right. And any mistake, any whatsoever, could move that doomsday clock up to midnight, this very night….for humans first.
Ah, but the IUCN tells us: Let’s focus just on critters for this exercise: Currently 2,129 animal species are on the critically endangered list. All of them are rated as 50% likely gone in three generations or 10 years, whichever is greater, up to a maximum of 100 years. Here’s the official definition:
As few animals of any kind live longer than 33.3 years, it’s safe to say most of those 2,129 critters (1,374 of which are vertebrates) are goners by 2100…sooner if things get worse faster. Which by the way….they probably are.
To be defined as critically endangered in the Red List, a species must meet ANY of the following criteria (A–E) ("3G/10Y" signifies three generations or ten years—whichever is longer—over a maximum of 100 years; "MI" signifies Mature Individuals):
A: Occurring over less than 100 km2 and two of:
1. Severe habitat fragmentation or existing at just one location
2. Decline in extent of occurrence, area of occupancy, area/extent/quality of habitat, number of locations/subpopulations, or amount of MI.
3. Extreme fluctions in extent of occurrence, area of occupancy, number of locations/subpopulations, or amount of MI.
B: As above, but less than 10 km2 (used to show differing levels of severity).
C: Declining population of less than 250 MI and either:
1. A decline of 25% over 1G/3Y;
But let’s be optimistic and just say every species gets 100 years, and the mass extinction rate won’t get worse.
Let’s be more optimistic and say it’s a steady geometric rate (smaller baseline of species = fewer extinctions per century, so eventually the die-off flattens out). Yay, life.
You know, before we have everyone crawling under a rock, we’ll arbitrarily say teh deth (that was LOLcat, editors) stops when the number of species of a given vertebrate class falls below 90% of circa 2010 levels. For purposes of our little exercise we will zoom in on classes of vertebrates. Those would be Amphibians, Birds, Bony Fish, Cartiliginous Fishes (Sharks, Skates, Rays), Coelecanths, Jawless Fish, Mammals and Reptiles.
Quibbles over the buckets are welcome but I’m not changing a darn thing for a Top Comments diary. :)
We’ll also need the total species number estimates for each, to calculate a depletion rate.
Once we put all that together we can produce our optimistic forecast of how long our Hollow Scene Mass Extinction Event will take to play out for us parochial, self-absorbed spinal column-possessing types.
Answer: Even optimistic is NOT optimistic
Now, a caveat: I’m not saying 90% of all species are going to go buh-buh. Hardly. If you’re an arthropod or a mollusk or a cephalopod or a jellyfish, the future’s probably going to play out nicely for you. Not for all of your species but, hey. Life rolls like that.
It just won’t roll for vertebrates for much longer. Last I checked, that means humans.
Now, what happened the last time large numbers of vertebrate species bought the farm? That would be the dinosaur extinction or K-T event, where 30% of all life and 100% of dinos punched their clocks. How long did that take? Given the near-consensus mechanism of a big ole rock smacking down near the current-day Mexican Riviera,..probably the big dinos died quickly and smaller ones petered out over time. It probably took a few million years for the evolutionary chaos to sort out, the resulting being the fossil evidence in the wake of the K-T Event is very, very sparse. There’s a paleontological gold mine out there waiting to be found but no one’s found it yet.
We’re not following the same pattern, yet. But we could… at least for ourselves. We could have that good ole fashioned Global ThermoChemoBioNuclear War. That would accelerate a lot of individual life extinction events. It would collapse more than a few ecosystems. And despite the occasional “the Earth would be better off if Humanity just up and died” comment, there is a nonzero risk that a short nuclear winter would be followed within 1-3 years by a nuclear summer.
My own opinion is we made this mess. We keep making it. Many among our educated classes are darn proud of the evidence of ‘making an impact’, even if a bad one. It means they have hands on a power to hurt people they don’t like by wrecking the world around them. Oh, they might not… if they get concessions… assurances…more of the respect they feel due…
Yet such people ought to look at the clock. Even if they style themselves cold-blooded, they’re still mammals. And mammals are among the first class of critters to walk the evolutionary plank, the way said cold cruel types are piloting the ship.
(Oh, look. Iceberg. Perhaps we should load up the lifeboats with our bling and set them aside, just in case…)