Artic Study Reveals World's Worst Mass Extinction Due to Global Warming
A study reveals that the world's last mass extinction happened because of global warming. This mass extinction, called the Great Dying Event, saw the demise of 96 percent of marine species and 70 percent of terrestrial life.
Jochen Knies, a researcher at CAGE who conducted the study in the Arctic, said the cause of this mass extinction is an "explosive event of volcanic eruptions" that happened in Siberia. He also said that amounts of volatiles such as carbon dioxides and methane were emitted by several eruptions that lasted for a million years. This emission made our planet "unbearably hot" during that time, Heritage Daily reports.
The Great Dying Event happened 252 million years ago, and it took nine million years after for life on Earth to recover from the catastrophe. The new study found clues in the Arctic and can now reveal why it took such a long time for recovery.
"What used to be the northwestern continental margin of the super continent Pangaea is now Canadian High Arctic. There we found evidence in geological records for a significant nutrient gap during this period. This means that global oceans were severely poor in nutrients such as nitrogen," Knies said via Science Daily.
During the Great Dying, the oceans' temperature (thermoclines) and nutrients (nutricline) suffered greatly because of high temperatures. Oceans are not a single body of water. There are actually layers and boundaries that are based on thermoclines and nutriclines. Both thermoclines and nutriclines deepened, ceasing the upwelling of nutrients from the bottom of the oceans. As a result, marine algae productivity decreased, crumbiling down the base of the food chain.
Only around six to seven million years after the extinction did the oceans started cooling off. The boundaries that prevented nutrients from going up to the surface were weakened. This paved way for the nutrients to return to the surface and sustain life again.
The study also proves how global warming can affect marine ecosystems in the long haul. The Great Dying Event or Permian-Triassic mass extinction has reset evolution. After this event, dinosaurs came but they also died out due to another mass extinction. The study notes that it's possible that humanity is facing another impending mass extinction due to human activity.