In a groundbreaking study, new fossil evidence has shed light on the mysterious 5-million-year heatwave that followed Earth’s most catastrophic extinction event—known as the Permian-Triassic Mass Extinction or the “Great Dying.” Researchers from the University of Leeds and the China University of Geosciences have uncovered how the collapse of tropical forests, compounded by volcanic activity, contributed to an era of intense global warming. Published in Nature Communications, this study offers a chilling warning about the fragility of our current climate systems.
The Great Dying: The Catalyst for Global Climate Change
Around 252 million years ago, Earth experienced the Permian-Triassic Mass Extinction, the most severe mass extinction event in the planet’s history. A series of catastrophic events—including massive volcanic eruptions in the Siberian Traps—led to the annihilation of nearly all marine species and a significant reduction in terrestrial life. What followed was a climate disaster that lasted for millions of years. Although volcanic eruptions are widely believed to have released vast amounts of carbon dioxide (CO2) into the atmosphere, scientists were left puzzling over why Earth remained so hot long after the eruptions ceased.
For decades, researchers believed the heat was the lingering effect of volcanic activity. However, fossil evidence uncovered by an international team of scientists has now revealed that the true cause of the persistent heatwave was the collapse of tropical forests. This loss of vegetation—critical for capturing and storing carbon—further exacerbated the already intense warming, resulting in what is now described as a global “super-greenhouse” climate.
The Collapse of Tropical Forests: A Key Driver of Warming
The research team, led by Dr. Zhen Xu from the University of Leeds, analyzed fossil records and geological data to reconstruct how plant life, especially tropical forests, changed during the extinction period. Their findings suggest that the widespread loss of these forests significantly reduced Earth’s ability to absorb CO2, a process known as carbon sequestration. This failure in carbon capture allowed atmospheric CO2 levels to remain elevated, continuing the warming process for millions of years.
Professor Benjamin Mills, co-author of the study, emphasized the critical importance of Earth’s tropical forests: “There is a warning here about the importance of Earth’s present-day tropical forests.” These forests, he explained, play a vital role in stabilizing the planet’s climate by removing CO2 from the atmosphere. Without them, the climate becomes more vulnerable to extreme warming events, much like what happened during the Permian-Triassic extinction.
Understanding the Long-Term Climate Impact
Dr. Zhen Xu, who spearheaded the study, stated, “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.” After years of detailed fieldwork and data analysis, Xu and her team were able to confirm that the loss of these forests—and the resulting failure in carbon sequestration—was a key driver of the prolonged heatwave.
The implications of these findings are profound. The tropical forest collapse during the Permian-Triassic extinction event serves as a grim reminder that ecosystems are interconnected with the climate in ways that we are only beginning to understand. Once tipping points are reached—where key ecosystems like tropical forests fail—global warming can spiral out of control. This process can continue for millions of years, making it nearly impossible for the planet to cool without significant, long-term intervention.
A Chilling Warning for Modern Climate Change
Professor Mills further warned, “If rapid warming causes [tropical forests] to collapse in a similar manner, then we should not expect our climate to cool to preindustrial levels even if we stop emitting CO2. Indeed, warming could continue to accelerate in this case even if we reach zero human emissions. We will have fundamentally changed the carbon cycle in a way that can take geological timescales to recover, which has happened in Earth’s past.”
The parallels between the past and present are striking. As human activities continue to drive climate change, there is a real risk that modern tropical forests—such as those in the Amazon and Southeast Asia—could face similar collapses. This would not only exacerbate climate change but could lead to a state of irreversible global warming, making it difficult for Earth to recover, just as it did after the Great Dying.
The Importance of Preserving Tropical Forests
The implications of this research are clear: preserving tropical forests is not just about maintaining biodiversity or protecting endangered species, it is about safeguarding the future of the planet’s climate. If these forests are destroyed or degraded, the planet may lose its ability to regulate atmospheric CO2, leading to uncontrollable climate feedback loops that could spell disaster for future generations.
The research also stresses the importance of sustainable land-use practices and the urgent need for global efforts to prevent further deforestation. Protecting these ecosystems must become a central focus of both climate mitigation and adaptation strategies.
As we face the ongoing challenges of climate change, scientists like Dr. Xu and Professor Mills urge us to heed the lessons from Earth’s distant past and work proactively to prevent a similar fate. The research calls for a shift in how we think about climate resilience, emphasizing that preserving the natural systems that regulate the climate is far more cost-effective than attempting to reverse the damage once it’s done.