Earth’s biggest mass extinction may have been caused by ‘Mega’ El Nio

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The worst mass extinction in Earth’s history may have been caused by a supercharged El Niño cycle.
The finding has implications for modern climate science: Researchers don’t know how current warming will affect the El Niño-La Niña cycle, but even a fraction of the disruption resulting from the world’s worst mass extinction would make life for humanity very difficult.
Life flourished in the Permian period (298.9 million to 251.9 million years ago).
The supercontinent Pangaea was ringed with lush forests where odd reptiles ranged alongside amphibians and whirring clouds of insects.
These rifts, known as the Siberian Traps, spewed massive amounts of carbon dioxide into the air.
Related: The 5 mass extinction events that shaped the history of Earth — and the 6th that’s happening now Exactly how the eruptions and the subsequent climate warming translated to mass death has been tricky to pin down.
Other large eruptions did not lead to mass extinction, Farnsworth said.
Sun, Farnsworth, and their colleagues modeled the impacts and showed that, on land, these El Niño events would have heightened the already-increasing temperatures caused by carbon-dioxide-forced warming.
Forests remove carbon dioxide from the atmosphere, so their loss allowed even more heat-trapping carbon to stay aloft.
—UV radiation pulse played a role in a mass extinction event, fossilized pollen reveals —Are we in a 6th mass extinction?

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A supercharged El Niño cycle could have been the cause of the worst mass extinction in Earth’s history.

According to recent research, the climatic shift that killed 90 percent of Earth’s species around 250 million years ago at the end of the Permian period was caused by an excess of carbon dioxide in the atmosphere. The discovery bears significance for contemporary climate science: Scientists remain uncertain about the impact of present warming on the El Niño-La Niña cycle, but even a small portion of the disturbance resulting from the greatest mass extinction on record would pose significant challenges to human survival.

“It becomes uncharted territory when we start pushing ourselves outside of those boundaries that we existed in for hundreds of thousands of years,” says Alex Farnsworth, a paleoclimate modeler at the University of Bristol in the United States and co-author of the study. K. stated to Live Science. .

During the Permian epoch (298 point 9 million to 251 point 9 million years ago), life was abundant. Encircled by verdant forests, the supercontinent Pangaea was home to a variety of reptiles, amphibians, and flying insects. Towering reefs in the oceans served as homes for sharks, bony fish, and spiral-shelled nautiluses.

Subsequently, enormous volcanic rifts in the present-day Siberia erupted. Carbon dioxide erupted from these rifts, also called the Siberian Traps, in large quantities. Even worse, they erupted in a region with plenty of coal seams, which likewise evaporated into the sky. Rock layers as far south as South Africa have been found to contain the geological fallout from this eruption.

Related: The six mass extinction events that are currently taking place, as well as the five that shaped Earth’s history.

It has been difficult to determine exactly how the eruptions and the ensuing warming of the climate led to mass deaths. Farnsworth stated that the mass extinction was not caused by other significant eruptions. Furthermore, the order in which the deaths occurred was peculiar: marine species died off first, and terrestrial animals went extinct before the worst effects of global warming.

Ocean temperatures can be inferred from the teeth of eel-like Permian creatures called conodonts, about which Yadong Sun, the study’s lead author and an earth scientist at the China University of Geosciences, has long been building a database. His findings show that the western part of Panthalassa, the ancient ocean that predated the Pacific, was originally warmer than the eastern part. But, just as it does with modern El Niño events in the Pacific, this gradient weakened as the end-Permian climate warmed, resulting in warmer temperatures in the east.

Farnsworth stated that the ultimate outcome was a string of exceptionally strong and protracted El Niños. Using models to simulate the effects, Sun, Farnsworth, and associates demonstrated that these El Niño events would have intensified the warming that is already occurring on land due to emissions of carbon dioxide. The species that depended on forests would have struggled and perished first. The loss of forests allowed even more heat-trapping carbon to remain in the atmosphere since forests absorb carbon dioxide from the atmosphere.

Farnsworth stated, “You get this runaway positive feedback in the system.”. According to the researchers’ report released on Thursday, September 21, Panthalassa reached temperatures of 104 degrees Fahrenheit (40 degrees Celsius) in the tropics due to the heat in the atmosphere, surpassing the survival threshold of most ocean organisms. 12%) in the scientific journal.

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It took millions of years for life on Earth to resume after the “Great Dying.”. Scientists now understand why.

Fossilized pollen indicates that a mass extinction event was caused by an ultraviolet radiation pulse.

—Is the sixth mass extinction currently underway?

A paleontologist from the University of Washington who studies the end-Permian extinction but was not involved in the study, Peter Ward, said, “This is the best paper I’ve seen yet linking what happened in the Permian to the present day.”. Ward described the paper’s implications as “terrifying.”. “The Siberian Traps contributed significantly more carbon dioxide to the atmosphere than humans do, likely about 2,500 parts per million (ppm), as opposed to 419 ppm today, according to Farnsworth. However, human activity is adding carbon to the atmosphere at a faster pace.

“Even a small portion of what the Permian did is terrible for society; what this paper is just an end member of how bad it can get,” Ward told Live Science. “The Earth system is becoming incredibly unstable, which is what our civilization needs stability for. “. .

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