The Great Dying and the Sixth Extinction
Elijah E Skjoldager
Virginia Earth Systems Scholars
A mass extinction is when fifty percent or more of the planets’ species go extinct (2018). There have been five of these mass extinctions throughout the course of Earth’s history. The first mass extinction, called the End Ordovician, happened four hundred and forty-four million years ago and eighty-six percent of species were lost (Richter, 2015). The second was the Late Devonian which happened three hundred and seventy five years ago and wiped out seventy five percent of species (Richter, 2015). The third, called the End Permian and nicknamed “The Great Dying”, happened two hundred and fifty-one million years ago and decimated the world killing a staggering ninety-six percent of all species (Richter, 2015). The fourth was the End Triassic that happened two hundred million years ago and killed eighty percent of species (Richter, 2015). The fifth was the End Cretaceous which happened sixty-six million years ago and seventy-six percent of species were lost (Richter, 2015). There is controversy today that we are in the midst if a sixth extinction.
Keywords: End Ordovician, Late Devonian, End Permian, End Triassic, End Cretaceous, extinction
The Great Dying and The Sixth Extinction
Many scientists believe that we are on the cusp of a sixth major extinction while others think that we have been it for the past ten thousand years. There is one thing that they agree with though and that is that humans are the main cause of it. These cases are called anthropogenic causes and they include: habitat destruction, overhunting, and global climate change just to name a few.
Humans have been overhunting species to extinction ever since we learned to make weapons. It also doesn’t help that we are overpopulating the world. This goes hand in hand with habitat destruction. We destroy the habitats of animals to make the weapons that kill them directly or indirectly through CO2 emissions.
Speaking of CO2 this is what is causing the world’s climate change. Carbon dioxide has a very long life in the atmosphere and so it will keep building up over time. CO2 traps heat from the sun inside and thus warms the earth causing climate change.
Another cause is invasive species. Animals like the brown tree snake that hitch a ride on a military cargo plane in the 1940’s kill animals that are native to those areas. Today there are no native birds in Guam because of these snakes. Humans introduce animals like this all over the world.
The number of species that you might hear are in the world is probably an underestimate. Animals are extremely hard to quantify because we have no idea if we have discovered them all. The ocean for example, is so vast that we have only explored five percent of it. The world is a vast place and we are probably not ever going to be able to find all the species.
The End Permian Extinction, or “The Great Dying,” was arguably the most destructive mass extinction in Earths history. It happened around two hundred and fifty-one years ago and killed ninety-six percent of Earths species. There are three main things that caused this extinction. The first one is the Siberian traps. The siberian traps cover a lot of are as shown in the figure below.
There were many interactions between Earths spheres. There was an interaction between the atmosphere and the lithosphere because of volcanic eruptions producing toxic gases. There was an interaction between the lithosphere and the hydrosphere by causing acid rain. Finally, there was the most prominent interaction which was between the lithosphere and the biosphere because the volcanic eruptions killed anything in the vicinity of it.
Daily, J. W. (2017, March 2). A Younger Siberian Traps. Retrieved April 16, 2018, from https://worldbuilding.stackexchange.com/questions/72672/a-younger-siberian-traps
Module 8 Final Project. (n.d.). Retrieved April 15, 2018, from https://vsgc.spacegrant.org/course/mod/assign/view.php?id=5357
Richter, V. (2015, July 06). The big five mass extinctions. Retrieved April 15, 2018, from https://cosmosmagazine.com/palaeontology/big-five-extinctions