Finally, We Know What Killed Sea Life in The Deadliest Mass Extinction in History

Finally, We Know What Killed Sea Life in The Deadliest Mass Extinction in History

SOURCE: Science Alert DATE: February 23, 2019 SNIP: Around 252 million years ago, Earth experienced catastrophic devastation – an extinction event so severe that it wiped out almost all of the life on Earth. Up to 70 percent of all land vertebrate species were killed off, and a massive 96 percent of all marine species, including the famous trilobite that had previously survived two other mass extinction events. It’s called the Permian-Triassic Extinction Event, also known as the Great Dying, and as far as we know, it was the most calamitous event in Earth’s history. It’s widely accepted that climate change is to blame – more specifically, that long-term volcanic activity in Siberia spewed so much material into the atmosphere that it wrapped the world in a shroud of ash for a million years, simultaneously blocking sunlight, thinning the ozone, dropping acid rain, and raising temperatures. Now scientists have demonstrated what obliterated the marine life: rising temperatures accelerated the metabolisms of ocean creatures, which increases their oxygen requirements, while simultaneously depleting the oceans of oxygen. The animals literally suffocated. And we’re experiencing similar atmospheric warming again today – only much faster than the Great Dying, which showed warning signs for 700,000 years before the event itself. “Under a business-as-usual emissions scenarios, by 2100 warming in the upper ocean will have approached 20 percent of warming in the late Permian, and by the year 2300 it will reach between 35 and 50 percent,” Penn said. “This study highlights the potential for a mass extinction arising from a similar mechanism under anthropogenic climate...
The ‘great dying’: rapid warming caused largest extinction event ever

The ‘great dying’: rapid warming caused largest extinction event ever

SOURCE: The Guardian DATE: December 6, 2018 SNIP: Rapid global warming caused the largest extinction event in the Earth’s history, which wiped out the vast majority of marine and terrestrial animals on the planet, scientists have found. The Permian mass extinction, known as the “great dying”, occurred around 252m years ago and marked the end of the Permian geologic period. The study of sediments and fossilized creatures show the event was the single greatest calamity ever to befall life on Earth, eclipsing even the extinction of the dinosaurs 65m years ago. Up to 96% of all marine species perished while more than two-thirds of terrestrial species disappeared. The cataclysm was so severe it wiped out most of the planet’s trees, insects, plants, lizards and even microbes. The great dying event, which occurred over an uncertain timeframe of possibly hundreds of years, saw Earth’s temperatures increase by around 10C (18F). Oceans lost around 80% of their oxygen, with parts of the seafloor becoming completely oxygen-free. Scientists believe this warming was caused by a huge spike in greenhouse gas emissions, potentially caused by volcanic activity. “It does terrify me to think we are on a trajectory similar to the Permian because we really don’t want to be on that trajectory,” Stanford University scientist Jonathan Payne said. “It doesn’t look like we will warm by around 10C and we haven’t lost that amount of biodiversity yet. But even getting halfway there would be something to be very concerned about. The magnitude of change we are currently experiencing is fairly large.” Curtis Deutsch, an oceanography expert at University of Washington said: “We are...