Ancient Tropical Forest Collapse Fueled 5-Million-Year Hothouse
The loss of carbon-sequestering plants prevented Earth from cooling after volcanic activity 252 million years ago.
Updated on Oct. 11, 2026 in Environmental
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A study into the Permian-Triassic extinction, which occurred 252 million years ago, reveals that the mass loss of tropical forests hindered Earth's ability to recover from volcanic carbon emissions. The subsequent absence of a terrestrial carbon sink trapped the planet in a five-million-year hothouse state.
Why it matters
The findings demonstrate how vegetation collapse can fundamentally break global carbon cycling mechanisms. This retrospective model shows how significantly reduced plant productivity can sustain extreme temperatures for millions of years.
Tropical plant productivity plummeted from 54 to 63 billion metric tons annually to between 13 and 20 billion in the early Triassic. This decline occurred as equatorial surface temperatures surged to between 91 and 93 degrees Fahrenheit.
The players
SCION
An Earth-system climate model used to simulate historical and future vegetation-climate interactions.
The details
Researchers mapped global plant productivity by integrating macrofossil and pollen data into the SCION Earth-system climate model. This model simulates how the loss of forest canopies, which shrank from 164 feet to a range of 2 inches to 6.5 feet, halted rock weathering and carbon burial. Without these active carbon sinks, volcanic CO2 emissions remained trapped in the atmosphere, maintaining the extreme hothouse conditions.
Timeline
252 million years ago: Pangea tropical forests collapsed during the Permian-Triassic transition.
Early Triassic: Earth remained in a five-million-year hothouse state.
2016: Researchers began field collection of fossil data across China.
2020: Researchers began work on the SCION climate simulation.
250 million years from now: Continents are projected to reassemble into Pangea Ultima.
The Tech Race
This study leverages the SCION climate model to quantify the Earth-system response to massive vegetation loss. The work provides a critical benchmark for future projections, specifically modeling how only 8 to 16 percent of the future Pangea Ultima supercontinent may remain mammal-habitable.
This research provides a foundational look at the historical relationship between terrestrial carbon sinks and surface temperatures. While the findings describe a deep-time event, they offer a data-backed baseline for understanding how vegetation loss alters planetary-scale temperature regulation.
The takeaway
The extinction event 252 million years ago highlights the necessity of massive forest systems for terrestrial carbon sequestration. Researchers continue to use models like SCION to refine predictions regarding the habitability of future reassembled supercontinents.
Further reading
Explore more findings regarding the long-term impacts of biological shifts on global climate in our Environmental section.
Source note: This article includes information reported by Earth.
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Do you trust that preserving today's tropical forests will prevent long-term global temperature increases?
