Global mean annual sea surface temperature anomalies (°C) against Changxing background conditions (412 ppm simulation). (A) SST anomaly between 857 ppm and 412 ppm simulations. (B) SST anomaly between 1712 ppm and 412 ppm simulations. (C) SST anomaly between 2568 ppm and 412 ppm simulations. (D) SST anomaly simulation between 4000 and 412 ppm. – science
A huge ocean-warming El Niño event was key to causing the largest extinction of life on Earth about 252 million years ago, according to a new study.
The study, published today in the journal Science and co-led by the University of Bristol and China University of Geosciences (Wuhan), shows that the effects of rapid climate change during the Permian-Triassic warming were so devastating to all forms of life. shed new light on the reasons for this impact. Life on land and sea.
Scientists have long linked this mass extinction to a massive volcanic eruption in what is now Siberia. The resulting carbon dioxide emissions rapidly accelerated climate warming, resulting in widespread stagnation and the collapse of marine and terrestrial ecosystems.
But what caused similar afflictions to land creatures, including plants and normally robust insects, remains a source of mystery.
Dr Alexander Farnsworth, co-lead author and senior research fellow at the University of Bristol, said: ‘As we are seeing today, when the tropics get too hot, species migrate to cooler, higher altitudes, so climate warming “No single species can cause such a catastrophic extinction.” latitude. Our research shows that increases in greenhouse gases are not only making large parts of the Earth warmer, but also increasing variability in weather and climate, making the Earth more ‘feral’ and making it harder for life to survive. has become clear. ”
The Permian-Triassic catastrophe shows that the problem of global warming is not just a matter of unbearably hot weather, but also a case of large fluctuations in conditions over decades.
“Most life could not adapt to these conditions, but thankfully some survived and without them we would not be where we are today. Although it was nearing the end of life on Earth, , it was not complete,” said co-author Yadong Sun, a professor at the China University of Geosciences in Wuhan.
The geology section reveals the arid (extremely dry) land surface that was common around the world 252 million years ago, a sign of our coming future. Trustworthiness of the University of Bristol and China University of Geosciences (Wuhan)
The magnitude of the warming between the Permian and Triassic periods was revealed by studying oxygen isotopes in the fossilized tooth material of extinct small swimming creatures called conodonts. By studying temperature records of conodonts around the world, researchers were able to show a significant collapse of temperature gradients at low and mid-latitudes.
Dr Farnsworth, who used pioneering climate modeling to assess the findings, said: The changes responsible for the identified climate patterns were profound, as there were El Niño events that were much more intense and prolonged than those witnessed today. Species did not have the ability to adapt or evolve fast enough. ”
In recent years, the El Niño phenomenon has caused significant changes in rainfall patterns and temperatures. For example, the extreme weather event that triggered the North American heatwave in June 2024 had temperatures about 15 degrees Celsius above normal. 2023-2024 was one of the hottest years on record globally due to the strong El Niño phenomenon that occurred in the Pacific Ocean, but human-induced increases in carbon dioxide caused catastrophic droughts and A fire broke out, further worsening the situation.
Surface temperature (°C) of the warmest month during the peak of warmth during the Permian-Triassic mass extinction 252 million years ago. Trustworthiness of the University of Bristol and China University of Geosciences (Wuhan)
“Fortunately, such events have historically lasted only one to two years at a time. During the Permian-Triassic crisis, El Niño lasted much longer, resulting in widespread, decade-long events. We had a drought followed by several years of flooding. Basically, the climate is everywhere, which makes it very difficult for any species to adapt.” says paleoenvironmental professor Paul Wignall.
Climate modeling results also help explain the abundance of charcoal found in rock layers from that era.
“In drought-prone climates, wildfires become much more common. The planet was in a crisis, with the land on fire and the oceans stagnant. There was nowhere to hide,” co-authors said. Professor David Bond, a paleontologist at the University of Hull, added:
The researchers found that while many volcanic events similar to Siberia have occurred throughout Earth’s history, many of which caused extinctions, none caused a crisis on the scale of the Permian-Triassic event. observed.
They argue that these mega El Niños caused positive feedbacks on climate, starting in the tropics and then extending beyond the tropics, resulting in incredibly warm conditions and resulting vegetation die-off during the Permian and Tertiary periods. They found that the Tatami Period extinctions were very different. Plants are essential for removing CO2 from the atmosphere and are the base of the food web. When plants die, we also lose one of Earth’s mechanisms that prevents CO2 from accumulating in the atmosphere as a result of continued volcanic activity.
This also helps explain the conundrum of the Permian-Triassic mass extinction, in which extinctions on land occurred tens of thousands of years before extinctions in the oceans.
“Oceans were initially protected from rising temperatures, but the Super El Niño event caused temperatures on land to rise faster than most species could tolerate, making it impossible for them to adapt in time,” Sun said. explained.
“Only species that could move quickly could survive, and there weren’t that many plants or animals that could do that.”
Mass extinctions, while rare, are the pulse of Earth’s natural systems resetting life and evolution onto a different path.
“While the Permo-Triassic mass extinction was catastrophic, the rise of dinosaurs will ultimately lead to the subsequent dominant species, just as the Cretaceous mass extinction led to the rise of mammals and humans.” Dr. Farnsworth concluded.
Mega El Niño caused end-Permian mass extinction, science says
astrobiology
