The collapse of tropical forests during Earth’s most catastrophic extinction event was the primary cause of the prolonged global warming that followed, according to groundbreaking new research published in Nature Communications. The Permian–Triassic Mass Extinction, also known as the “Great Dying,” occurred around 252 million years ago, resulting in the massive loss of marine species and significant declines in terrestrial plants and animals.
Scientists have long attributed the event to intense global warming triggered by volcanic activity in Siberia, known as the Siberian Traps. However, the reason why super-greenhouse conditions persisted for around five million years afterward has remained a mystery. A team of international researchers led by the University of Leeds and the China University of Geosciences in Wuhan has now shed light on this puzzle.
Through extensive field studies and innovative analyses of fossil records and rock formations, the researchers reconstructed maps of changes in plant productivity during the Permian–Triassic Mass Extinction. Their findings indicate that the demise of tropical forests and their slow recovery limited carbon sequestration, leading to high levels of CO2 in the atmosphere for an extended period.
Dr. Zhen Xu, the lead author of the study, highlighted the significance of the research, stating, “The causes of such extreme warming during this event have been long discussed, as the level of warming is far beyond any other event. Critically, this is the only high-temperature event in Earth’s history in which the tropical forest biosphere collapses, which drove our initial hypothesis.”
The researchers believe that their results demonstrate the existence of thresholds or ‘tipping points’ in Earth’s climate-carbon system, where warming can be amplified once reached. By leveraging China’s rich geological record of the Permian-Triassic Mass Extinction, the team was able to gather crucial data that supports their hypothesis.
Professor Benjamin Mills from the University of Leeds emphasized the importance of Earth’s present-day tropical forests, warning that if rapid warming were to cause their collapse, the climate may not cool even if human CO2 emissions are reduced to zero. This underscores the need to protect and preserve tropical forests to avoid irreversible changes to the carbon cycle.
In conclusion, the study’s authors stressed the urgency of blending traditional paleontological techniques with new approaches to decode the past and safeguard the future. They emphasized that the responsibility to protect Earth’s ecosystems and climate falls on all of us, urging for collaborative efforts to shape a sustainable future for the planet.
This article, based on a press release from the University of Leeds, was rewritten by Brendan Montague, an editor at The Ecologist, to highlight the importance of the research findings in understanding past extinction events and their implications for current climate challenges.
