A 252-million-year-old mass extinction event, known as the Permian-Triassic mass extinction or the Great Dying, occurred when almost all life on Earth disappeared. The most catastrophic of five mass extinction events in the past 539 million years was triggered by a sudden surge in greenhouse gases resulting from massive volcanic eruptions.
These eruptions led to intense warming, causing up to 94% of marine species and 70% of terrestrial vertebrate families to be wiped out. Tropical forests, which are crucial for regulating the planet’s temperature, experienced significant declines.
Scientists had long suspected that a combination of factors contributed to the Great Dying. New research now confirms this theory by examining fossil records and reconstructing plant life before and after the mass extinction event.
A key discovery is that the decline of tropical forests created conditions that “locked” Earth in a hothouse state, allowing catastrophic ecological collapse to follow. These findings provide evidence for the concept of tipping points, where extreme climate changes can lead to irreversible ecological consequences.
The massive eruptions occurred in Siberia and released vast amounts of carbon dioxide into the atmosphere, causing temperatures to rise by 6-10°C. However, these conditions persisted for roughly five million years due to a reduction in plant growth.
Only when plants re-established themselves and the organic carbon cycle restarted did Earth start to recover from the super greenhouse state. The study highlights the importance of tropical and subtropical biomes in maintaining climate equilibrium.
The researchers suggest that such mass extinctions can occur due to rapid changes in plant life, making it challenging for ecosystems to adapt on short time scales. This underscores the devastating impact of losing these critical biomes and their role in exacerbating climate change.
Source: https://theconversation.com/around-250-million-years-ago-earth-was-near-lifeless-and-locked-in-a-hothouse-state-now-scientists-know-why-260203