The Great Dying at the end of the Permian Period, occurring approximately 250 million years ago, may have been intensified by exceptionally strong and prolonged El Niño events. This finding suggests that these mega El Niños resulted in drastic climate fluctuations that devastated forests and numerous terrestrial species, according to recent research from the University of Bristol.
These El Niño events initiated feedback mechanisms that significantly contributed to the severity of this mass extinction. “There are cascading effects when such enduring and powerful El Niño events occur,” the researchers indicate.
During the end-Permian extinction, nearly 90 percent of all species at the time are believed to have vanished, marking it as the largest mass extinction event in Earth’s history, likely triggered by massive volcanic eruptions in present-day Siberia. These eruptions emitted vast amounts of carbon dioxide—potentially from heating fossil carbon-rich rocks—leading to extreme global warming. This resulted in stagnant oceans low in oxygen, which devastated marine life.
Notably, land species began to face extinction tens of thousands of years prior to their marine counterparts, prompting multiple hypotheses, such as volcanic winters and the depletion of the ozone layer. Recent studies exploring ancient ocean temperatures have suggested a possible link with extreme El Niño events.
The research team, utilizing computer models, assessed atmospheric conditions at the end of the Permian to validate these findings. While modern El Niño events involve warm water shifting from the western Pacific to the east, they discovered that pre-extinction El Niños were likely similar in intensity and duration to present-day events but had a much greater geographical impact due to the broader oceanic expanse of Panthalassa.
As carbon dioxide levels rose during this period, El Niños intensified and became more prolonged. The models indicated that these extreme conditions caused significant weather swings on land, resulting in the destruction of forests that could no longer absorb CO2, further exacerbating global warming and leading to even more extreme El Niños.
In contrast, marine temperature variations were less severe, allowing marine species to migrate more easily, which is why ocean extinctions progressed later as global temperatures surged. “The extreme global warming that triggered marine extinctions was intensified by the loss of these carbon-absorbing forests,” the research explains.
By the peak of this extinction event, the temperature shift during El Niños reached as much as 4°C (7.2°F), with sustained events lasting over a decade.
Uncertainty remains about future El Niño patterns; models differ on how these events will evolve as global temperatures rise. Already, recent El Niño activity has resulted in record-breaking temperatures and widespread forest fires, raising concerns about ecosystem resilience.
“The recent El Niño contributed to unprecedented temperatures worldwide and significant forest fires,” researchers highlighted. “There are concerning indicators of forest dieback in critical ecosystems like the Amazon.”
The study indicates that under certain climatic conditions, El Niño events can lead to extinctions. However, the larger oceanic basin of Panthalassa, which doesn’t exist today, facilitated those mega El Niños, making similar occurrences unlikely in the present climate context.
Experts stress the importance of understanding historical climate patterns to better anticipate future changes. They emphasize that while this research sheds light on the past extinction events, it does not provide a clear forecast for near-future El Niño impacts.
