We really need to educate ourselves on this specious propaganda.
Here’s a good beginning.
https://phys.org/news/2017-07-earth-major-mass-extinction-events.html
Most scientists agree that a “mass extinction” event is underway with the Earth’s wildlife disappearing at an alarming rate, mainly due to human activity.
But this is not the first time: over the last half-billion years there have been five major wipeouts in which well over half of living creatures disappeared within a geological blink of the eye. All told, more than 90 percent of organisms that have ever strode, swam, soared or slithered on Earth are now gone.
Here are the biggest die-offs, each showing up in the fossil record at the boundary between two geological periods:
Ordovician extinction
When: about 445 million years ago
Species lost: 60-70 percent
Likely cause: Short but intense ice age
Most life at this time was in the oceans. It is thought that the rapid, planet-wide formation of glaciers froze much of the world’s water, causing sea levels to fall sharply. Marine organisms such as sponges and algae, along with primitive snails, clams, cephalopods and jawless fish called ostracoderms, all suffered as a consequence.
Devonian extinction
When: about 375-360 million years ago
Species lost: up to 75 percent
Likely cause: oxygen depletion in the ocean
Again, ocean organisms were hardest hit. Fluctuations in sea level, climate change, and asteroid strikes are all suspects. One theory holds that the massive expansion of plant life on land released compounds that caused oxygen depletion in shallow waters. Armoured, bottom-dwelling marine creatures called trilobites were among the many victims, though some species survived.
Permian extinction
When: about 252 million years ago
Species lost: 95 percent
Possible causes: asteroid impact, volcanic activity
The mother of all extinctions, the “Great Dying” devastated ocean and land life alike, and is the only event to have nearly wiped out insects as well. Some scientists say the die-off occurred over millions of years, while others argue it was highly concentrated in a 200,000-year period.
In the sea, trilobites that had survived the last two wipeouts finally succumbed, along with some sharks and bony fishes. On land, massive reptiles known as moschops met their demise. Asteroid impacts, methane release and sea level fluctuations have all been blamed.
Triassic extinction
When: about 200 million years ago
Species lost: 70-80 percent
Likely causes: multiple, still debated
The mysterious Triassic die-out eliminated a vast menagerie of large land animals, including most archosaurs, a diverse group that gave rise to dinosaurs, and whose living relatives today are birds and crocodiles. Most big amphibians were also eliminated.
One theory points to massive lava eruptions during the breakup of the super-continent Pangea, which might have released huge amounts of carbon dioxide, causing runaway global warming. Other scientists suspect asteroid strikes are to blame, but matching craters have yet to be found.
Cretaceous extinction
When: about 66 million years ago
Species lost: 75 percent
Likely cause: asteroid strike
An space rock impact is Suspect No. 1 for the extinction event that wiped out the world’s non-avian dinosaurs, from T-Rex to the three-horned Triceratops. A huge crater off Mexico’s Yucatan Peninsula supports the asteroid hypothesis.
Read more at: https://phys.org/news/2017-07-earth-major-mass-extinction-events.html#jCp
From the Triassic:
“One theory points to massive lava eruptions during the breakup of the super-continent Pangea, which might have released huge amounts of carbon dioxide, causing runaway global warming. Other scientists suspect asteroid strikes are to blame, but matching craters have yet to be found.”
“Runaway global warming.” Which was corrected, by the planet, all by itself.
Same with the short, intense ice age mentioned in another section. Corrected.
The planet is a self-correcting system, even overcoming “runaway global warming” and ice ages.
Add:
Mass extinctions about 10,600 years ago - cause likely Taurid meteor (one mile diameter fragment of large ‘dark’ comet) ended the Younger Dryas, the coldest period known - glaciers began reforming after previous I mile diameter space rock hit Ice Cap causing massive floods and melting raising temperatures to near present day 1000 years prior.