New Fossil Evidence Suggests Climate Tipping Point During Great Dying

In a groundbreaking study published in *Nature Communications* on July 4, 2025, a team of researchers from the University of Leeds and the China University of Geosciences in Wuhan has revealed significant findings regarding the Permian-Triassic Mass Extinction, often referred to as the "Great Dying." This extinction event, which occurred approximately 252 million years ago, is characterized by the catastrophic loss of marine life and severe declines in terrestrial biodiversity. The research indicates that the collapse of tropical forests during this period led to reduced carbon sequestration and prolonged global warming, thereby crossing critical climate tipping points.

The study, led by Dr. Zhen Xu, a researcher at the University of Leeds' School of Earth and Environment, synthesized new fossil data and geological evidence to reconstruct ancient plant productivity and climate conditions during the extinction. Dr. Xu stated, "Critically, this is the only high temperature event in Earth’s history in which the tropical forest biosphere collapses, which drove our initial hypothesis. Now, after years of fieldwork, analysis and simulations, we finally have the data which supports it."

In their analysis, the researchers utilized advanced methods to examine fossil records and past climate indicators found in various rock formations. The findings highlight that the loss of tropical vegetation severely limited the Earth's capacity to sequester carbon dioxide, leading to a super-greenhouse climate that persisted for about five million years after the extinction event. This research not only sheds light on the historical context of the Great Dying but also emphasizes the potential implications for current climate change scenarios.

Professor Benjamin Mills, also from the University of Leeds, emphasized the contemporary relevance of this research, warning that if today’s tropical forests were to collapse due to rapid climate change, the consequences could be dire. He remarked, "If rapid warming causes them 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."

The study underscores the importance of understanding climate-carbon system thresholds. As noted by the researchers, once these tipping points are crossed, the ramifications can lead to prolonged periods of intensified warming, a scenario observed during the Great Dying. The research team’s work draws upon decades of geological and paleontological studies conducted in China, which holds a comprehensive fossil record of this extinction event.

Historically, the Permian-Triassic Mass Extinction has been linked to volcanic activities in the Siberian Traps, which released substantial amounts of greenhouse gases into the atmosphere, driving temperatures higher. Despite this understanding, the reasons for the prolonged super-greenhouse conditions had remained elusive until this new study. By correlating fossil evidence with climate data, the researchers were able to provide a clearer picture of how the extinction event influenced long-term climate patterns.

The implications of this research extend beyond academic inquiry. Professors Hongfu Yin and Jianxin Yu from the China University of Geosciences stressed the need for paleontology to adopt innovative methodologies to analyze past climates in order to better inform present-day climate policy. Professor Yin stated, "Paleontology needs to embrace new techniques—from numerical modelling to interdisciplinary collaboration—to decode the past and safeguard the future."

As the world grapples with the realities of climate change, the lessons from Earth’s history serve as a sobering reminder of the delicate balance within our climate system. The research not only provides insights into the past but also emphasizes the urgent need for action to prevent a similar trajectory in the future. The study’s findings are a clarion call for ongoing research and policy action to address the pressing challenges posed by climate change, thereby ensuring a sustainable future for the planet and its inhabitants.