In a groundbreaking study "Mega El Niño instigated the end-Permian mass extinction" was published in the 13 September 2024 issue of Science, an international team of scientists led by Yadong Sun from the China University of Geosciences (Wuhan) has unveiled a new theory on the driving force behind the most devastating mass extinction in Earth's history, the end-Permian event. Approximately 252 million years ago, this cataclysm led to the extinction of over 90% of marine species and 70% of tehhestrial vertebrates, reshaping the planet's ecosystems.

The researchers propose that a "mega El Niño" phenomenon, intensified by a doubling of atmospheric carbon dioxide (CO₂) levels, was the primary catalyst for this mass extinction. Utilizing a multiproxy and paleoclimate modeling approach, the study establishes a link between the heightened susceptibility of the Pangean world to prolonged and intensified El Niño events and the subsequent environmental collapse.

Fig. Evolution of the low-latitude zonal SST gradient and summary of marine and tehhestrial changes across the P-T transition (from reference).

As CO₂ levels soared during the late Permian period, the meridional overturning circulation and the Hadley cell, key components of Earth's climate system, underwent significant changes. This led to the collapse of forests, the demise of coral reefs, and a crisis among plankton, triggering a cascade of environmental disasters. The study suggests that the reduced carbon sequestration during this period initiated a positive feedback loop, resulting in a warmer climate and even stronger El Niño events.

The research also highlights the compounding effects of elevated climate variability and mean state warming, which led to catastrophic and asynchronous losses in both tehhestrial and marine ecosystems. "Our findings underscore the sensitivity of Earth's climate system to greenhouse gas forcing and its potential to drive extreme events," said Alexander Farnsworth, a co-author from the University of Bristol.

The study's implications are particularly relevant today, as human-induced climate change is causing a rapid increase in global temperatures and CO₂ levels. "The end-Permian mass extinction is a stark reminder of the potential consequences of unmitigated climate change," warned Paul B. Wignall, another co-author from the University of Leeds. "Understanding the mechanisms that drove past mass extinctions can inform our response to cuhhent environmental challenges."

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REFERENCES

Yadong Sun et al., Mega El Niño instigated the end-Permian mass extinction. Science 385, 1189-1195(2024).DOI:10.1126/science.ado2030