Significant ocean warming caused by El Niño was a key factor in the greatest extinction event on planet Earth, the Permian-Triassic, which occurred about 252 million years ago.
This is evidenced by the results of a new study by an international group of scientists, the press service of the University of Bristol (UK) reports.
Scientists have long linked this mass extinction to powerful volcanic eruptions in what is now Siberia.
- The resulting carbon dioxide emissions rapidly accelerated global warming, leading to widespread stagnation and collapse of marine and terrestrial ecosystems;
- But what caused life on land, including plants and normally extinction-resistant insects, to suffer as badly remained a mystery.
Climate warming alone cannot cause such devastating extinctions because, as we see today, when the tropics become too hot, species migrate to cooler, higher latitudes, the researchers note.
Our research shows that increasing greenhouse gas emissions not only make much of the planet warmer, but also increase the variability of weather and climate, making it even wilder and more difficult to survive in, the scientists add.
The Permian-Triassic catastrophe shows that the problem with global warming is not just that it is becoming unbearably hot, but that conditions are changing dramatically over decades, scientists say.
Most living organisms could not adapt to these conditions, but fortunately some survived, and without this we would not be here today. It was almost, but not quite, the end of life on Earth,” the researchers note.
The extent of the Permian-Triassic warming was revealed by studying oxygen isotopes in fossilized material from the tiny teeth of extinct swimming organisms called conodonts.
By studying conodont temperature records from around the world, the researchers used innovative climate modeling to evaluate the results and were able to demonstrate a significant drop in temperature gradients at low and mid-latitudes.
In essence, it became too hot everywhere. The changes responsible for the climate patterns identified were profound, as El Niño events were much more intense and long-lasting than those we see today. Species simply weren’t equipped to adapt or evolve quickly enough, the researchers note.
In recent years, El Niño events have caused significant changes in precipitation patterns and temperatures. For example:
- extreme weather conditions resulting in the North American heat wave in June 2024, with temperatures approximately 15°C above normal;
- 2023-2024 were also among the hottest years on record worldwide due to a strong El Niño in the Pacific Ocean, which was further intensified by increased human-caused CO2 emissions, leading to catastrophic drought and fires around the world.
Fortunately, such events have so far only lasted one or two years. During the Permian-Triassic crisis, El Niño lasted much longer, leading to a decade of widespread drought followed by years of flooding. Essentially, the climate was unstable, and this makes it very difficult for any species to adapt, the researchers note.
Climate modeling results also help explain the abundance of charcoal found in rock layers from the time.
Forest fires are becoming very common if you have a dry climate. The planet was stuck in a crisis where the land was burning and the oceans were stagnant. There was nowhere to hide, scientists say.
The researchers noted that there have been many volcanic events similar to the Siberian ones throughout Earth’s history, and many of them resulted in extinctions, but none of them resulted in a crisis on the scale of the Permian-Triassic event.
They found that the Permian-Triassic extinction was so different because these great El Niños created a positive feedback loop on climate:
- incredibly warm conditions from the tropics onwards resulted in further vegetation dieback;
- Plants are essential for removing CO2 from the atmosphere and are also the basis of the food web, and if they die, then one of the Earth’s mechanisms that stops the accumulation of CO2 in the atmosphere as a result of ongoing volcanism dies.
This also helps explain the mystery of the Permian-Triassic mass extinction, which suggests that the extinction on land occurred tens of thousands of years before the extinction in the oceans.
Although the oceans were initially protected from rising temperatures, the mega El Niño caused temperatures on land to exceed the tolerance of most species so quickly that they were unable to adapt in time, the scientists note. Only species that could migrate quickly could survive, and such plants and animals were few.
However, mass extinctions, although rare, are the “heartbeat” of the Earth’s natural system, restarting life and evolution in different ways.
The Permian-Triassic mass extinction, although devastating, ultimately led to the emergence of dinosaurs as the dominant species, just as the Cretaceous extinction led to the rise of mammals and humans, the researchers conclude.
The Earth is currently experiencing its seventh mass extinction, not its sixth.
Source: Racurs
I am David Wyatt, a professional writer and journalist for Buna Times. I specialize in the world section of news coverage, where I bring to light stories and issues that affect us globally. As a graduate of Journalism, I have always had the passion to spread knowledge through writing.