An analysis of sedimentary deposits laid down in the times bracketing the Permian extinction reveals something a bit unsettling: the Earth’s biota was thriving and doing just fine right up to the sudden end, and then almost all species abruptly kicked the bucket in a geological flash.
The end-Permian mass extinction, which took place 251.9 million years ago, killed off more than 96 percent of the planet’s marine species and 70 percent of its terrestrial life—a global annihilation that marked the end of the Permian Period.
The new study, published today in the GSA Bulletin, reports that in the approximately 30,000 years leading up to the end-Permian extinction, there is no geologic evidence of species starting to die out. The researchers also found no signs of any big swings in ocean temperature or dramatic fluxes of carbon dioxide in the atmosphere. When ocean and land species did die out, they did so en masse, over a period that was geologically instantaneous.
So what could have caused the sudden, global wipeout? The leading hypothesis is that the end-Permian extinction was caused by massive volcanic eruptions that spewed more than 4 million cubic kilometers of lava over what is now known as the Siberian Traps, in Siberia, Russia. Such immense and sustained eruptions likely released huge amounts of sulfur dioxide and carbon dioxide into the air, heating the atmosphere and acidifying the oceans.
Complicating matters, though, is that these eruptions proceeded for a long time before, during, and after the mass extinction, so it seems that life persevered until it reached an abrupt breaking point, and then ecosystems collapsed.
“We can say there was extensive volcanic activity before and after the extinction, which could have caused some environmental stress and ecologic instability. But the global ecologic collapse came with a sudden blow, and we cannot see its smoking gun in the sediments that record extinction,” Ramezani says. “The key in this paper is the abruptness of the extinction. Any hypothesis that says the extinction was caused by gradual environmental change during the late Permian—all those slow processes, we can rule out. It looks like a sudden punch comes in, and we’re still trying to figure out what it meant and what exactly caused it.”
“This study adds very much to the growing evidence that Earth’s major extinction events occur on very short timescales, geologically speaking,” says Jonathan Payne, professor of geological sciences and biology at Stanford University, who was not involved in the research. “It is even possible that the main pulse of Permian extinction occurred in just a few centuries. If it turns out to reflect an environmental tipping point within a longer interval of ongoing environmental change, that should make us particularly concerned about potential parallels to global change happening in the world around us right now.”
This is why we need a big-picture perspective of our planetary environment. It’s like a game of Jenga — we keep knocking out little bits and pieces (or species or biomes) and congratulating ourselves that the tower is still standing, but eventually we’ll reach the point where one last insult causes everything to topple. Then, I’m sure, there will be people lying in the rubble, wondering why they’re starving or dying of disease or watching the natural catastrophe rolling in their direction, and they’ll be totally surprised by it all.
But hey, the climate has always been changing before, why should we worry about it changing now?
/stoopid
Maybe “the great filter” is a set of filters.
That seems right. Ecosystems have a lot of resilience, but too many stresses and they can rapidly destabilize and collapse (sort of like how the Grand Banks fisheries rapidly collapsed after years of overfishing). Given what was happening at the same time, the Permian biosphere may have been so vulnerable by the time the Extinction occurred that something that otherwise wouldn’t cause a mass extinction finally tipped things over.
It’s not just biological ecosystems, either. Political ecosystems tend to be like that as well.
Jenga works. Another metaphor involved rivets on an airplane: https://www.nytimes.com/2000/07/04/science/essay-lost-rivets-and-threads-and-ecosystems-pulled-apart.html
But both kind of allude to pieces (species?) going missing. We are currently losing species at a pretty high rate (unknown if this would be detectable in a future fossil record), in contravention of the intelligent tinkerer’s motto (“keep all the pieces”). But so far it seems the tipping point for the Permian is invisible to us — what went missing? And why was it worse in the oceans than on land?
It was the Great Flood!
(Ron Howard voiceover: “It was not the flood…”)
Damn Serpent Folk!
Why worry? Gawd will take care of it!
.
.
Now I need to wash this bad taste out of my mouth.
You know the Nuttings will incorporate this rapid extinction info into next year’s talk at the UMN as support for the flood and argue that there issue between the two ‘hypotheses’ is in interpretation ignoring all the data indicating the age of the earth, universe, etc.
@8 Yes, creationists are unable to cope with the concept of debate in science and of new findings modifying previous findings so that, dare I say it, hypotheses evolve. I guess that is because there is no concept of debate in fundamentalist religion – the bible is the bible is the bible. It is made quite explicit by the likes of Hovind and Ham who demand total acceptance of every single word as interpreted by a team of religious writers working for King James.
It is interesting that the human race seems totally unable to comprehend the idea of tipping points in climate change. They are a part of folklore (“a stitch in time saves nine”, “the straw that broke the camel’s back”) but not when it comes to understanding the future climate of the planet.
slatham@4–
That’s a good question, would future paleontologists see the effect of human-related extinction in the fossil record?
My feeling is that they would. We’ve almost eradicated bird and mammal wildlife entirely (best current global biomass estimate: livestock 100 MtC, humans 60 MtC, wild mammals 7 MtC, wild birds 2 MtC), and the processes of habitat destruction and climate change are only accelerating. If we set wild mammal + wild bird biomass =1, then human biomass =6.7 and livestock biomass =11.1.
I’m pretty confident this would be noticeable in the fossil record. It also suggests to me that any future paleontologists might very well not be human,.
Yeah, though every time he “takes care of” something, a heckuva lotta people seem to end up dead….
I wonder if we will be able to preserve enough of our technology and civilization in the coming catastrophe to be able to eventually rebuild. I am sure our technology is good enough for people to design technical solutions, but I am worried that when the most severe consequences of climate change kick in the result will be wars that ravage all infrastructure that makes civilization possible. It’s probably going to get ugly.
Cthulhu Shrugged
chrislawson@10: “That’s a good question, would future paleontologists see the effect of human-related extinction in the fossil record?”
I take that to be two questions: first, would they see the current extinction event as an extinction event in the fossil record? and second, would they then recognize it as “human-related” (in some sense)?
As to the first, I am not qualified to hold an opinion, nor do I in fact hold one (although I hold plenty of other opinions on subjects where I have equally inadequate qualifications). As to the second, I assume that, if and when the International Union of Geological Sciences decides that it’s time to officially accept the pending proposal to define an Anthropocene Epoch, one of their decisive criteria will be the assumption that future paleontologists would be able to read in various features of the geological record () discoverable by them sufficient evidence (including decay-product profiles of artificial nucleotides) that some biological agents had been around doing some highly “artificial” stuff at more or less the same time (geologically) as the extinction. Would the future paleontologists be able to conclusively pin the whole extinction on specific species in whatever (fossil and artefactual) record they’re able to investigate? Again, I’m unqualified to opine.
I once did a paper for uni comparing the current loss of population – not biodiversity, overall population of macrofauna – to the great dying; if anything, it was faster by my somewhat unscientific method of using the find rate of disjointed Lystrosaurus fossils as a metric of recruitment failure and overall loss of population; it suggests that our own rate of biomass loss was well faster then then. I would like to revisit the concept if I have time and cash to do that research.
Terrifying, that we seem to be sending ourselves down to the same fate as our own forebears, at our own hands.
leerudolph @11:
I’m certain that if in another 10 million or 100 million years, a species arises with sufficient intelligence to reinvent paleontologists that they’ll figure out that the proliferation of a species of bipedal ape across the globe coincides with mass extinctions of megafauna on every continent said ape began to colonize, and after about 40,000 years the extinction rate increased as a few specific species whose bones were often found in the ape’s rubbish piles also flourished.
For those of us not enough up on paleontology and looking for some perspective, “abrupt” in the case of the PT extinction event was apparently about 61000 years.
… “abrupt” in the case of the PT extinction event was apparently about 61000 years.
Which was even scarier, as the animals now had time to ponder their imminent demise and suspect one another as tensions rose. Diabolically clever.
The idiots will blame irrelevant things.
canadiansteve @ # 14: I wonder if we will be able to preserve enough of our technology and civilization in the coming catastrophe to be able to eventually rebuild.
Almost certainly not. Imagine (rather optimistically) a period of chaos which knocks humanity back technologically, say, 500 years.
Except this time practically all the ores, etc (even, oh irony, the fossil fuels) accessible to 16th-century engineers will be gone. Some metal extraction may be possible in dumps and junkyard sites (with even more toxic hazards than in late-medieval-period mines), but most everything useful will have oxidized past recovery.
Those brave enclaves and priesthoods preserving the knowledge of the past, à la Walter Miller, won’t have much to work with.