Learning from the Past: How Past Extinctions Shed Light on Current Climate Change
By: Andrew D. France
Despite our perception that mass extinctions are a thing of the past, there remains a threat that is all too frequently ignored right in front of us. In this article, we will make comparisons between past extinctions and the current climate problem by looking at recent studies, highlighting their relevance to today’s climate crisis.
Unveiling the Capitanian Mass Extinction:
Recent studies have revealed a pattern of cause and effect that is consistent with prior historical mass extinctions. 8–10 million years before the end-Permian mass extinction, there was the Capitanian mass extinction. While not many know about it, this incident turned out to be highly catastrophic. According to scientific estimates, up to 62 percent of species may have gone extinct as a result of this event.
Massive volcano eruptions, global warming, the demise of terrestrial ecosystems, and the expansion of oxygen-deprived dead zones in the oceans are noted to be the causes of this calamity. Fossil evidence also shows that this event triggered a significant decline in marine and terrestrial life, affecting corals, mollusks, reptiles, and more.
Previously, the Capitanian mass extinction was grouped together with the end-Permian extinction. Only recently have scientists discovered that the Capitanian mass extinction is a completely separate event. “In a way, the extinction losses have been hiding in the shadow of the end-Permian extinction,” said Paul Wignall, a professor at the University of Leeds and a co-author of Song’s paper. “It wiped out a lot of generations of all the usual things in the sea,” adding, “a bunch of animals died on land,” as well.
Investigating the past:
Two separate research teams conducted in-depth analyses to understand the cause and effect of the Capitanian extinction. Huyue Song and colleagues explored mid-Permian rocks at Penglaitan in China, finding evidence of two distinct extinction pulses. Each of these pulses coincided with widespread oxygen-starved ocean regions known as “anoxic dead zones,” leading to the detriment of marine life.
The second paper, led by Kunio Kaiho, examined the second pulse of extinction, unveiling hints of soil erosion and deforestation at the time. High-temperature wildfires and volcanic eruptions were identified as potential climate disruptors, bringing on an increase in precipitation and severe soil erosion, contributing to the anoxic conditions in the oceans.
Why we should worry:
Although geological mass extinctions occurred on bigger scales and over longer periods, they share several characteristics with current human-induced climate change. The modern combustion of fossil fuels, which causes climate instability and drought-related tree die-offs, is comparable to the surge in CO2 emissions from volcanic eruptions in the past. “The Kaiho paper, the increased burning… indicates a climate that’s becoming more prone to drought,” said Wignall. “You’re losing your forests on land.”
“High-temperature wildfires, such as the recent ones witnessed in Australia, can contribute to the formation of coronene,” Kaiho told Ars, but “most… coronene comes from volcanic eruptions.” This ties volcanic eruptions to the die-off when those rocks were forming. Kaiho thinks the volcanic eruptions disrupted the climate, bringing rainfall deluges: “Global warming causes an increase in precipitation, which induces large amounts of soil erosion,” he said.
Wignall claims that the Capitanian mass extinction followed a pattern that has been seen in the majority of mass extinction events. The occurrence of anoxia, which causes ocean stagnation, huge igneous provinces, intense volcanic activity, and rapid global warming are all connected to this pattern. The Capitanian mass extinction, once overshadowed by its more famous counterpart, has emerged as a crucial event in understanding the recurring patterns of cause and effect in mass extinctions.
These recent research findings emphasize the importance of learning lessons from the past in light of climate change and its significant effects on our ecosystem. The investigation of the Capitanian extinction serves as an alarming indicator of the disastrous effects brought on by climate change and changes in terrestrial ecosystems.
It serves as a wake-up call for us to act and address the effects of climate change. The extinction of the Capitanian serves as a warning that the fate of millions of species and the condition of our planet will be decided by our actions in the present. Looking into the past gives us the knowledge we need to create a more sustainable future in which we can live in harmony with nature and preserve it for future generations.
Earth and Planetary Science Letters, 2023. DOI: doi.org/10.1016/j.epsl.2023.118128
Palaeogeography, Palaeoclimatology, Palaeoecology, 2023. DOI: doi.org/10.1016/j.palaeo.2023.111518