The most catastrophic mass extinction event in Earth’s history, known as the Permian-Triassic mass extinction or “the Great Dying,” occurred approximately 252 million years ago, wiping out nearly all life on the planet. This devastating event is believed to have been triggered by a massive volcanic eruption in modern-day Siberia, which released large amounts of greenhouse gases into the atmosphere, causing rapid warming and extreme conditions.
Scientists have long suspected that a sudden increase in temperature was the primary cause of this mass extinction, but the question remained: why did these hot conditions persist for millions of years. A new study published today in Nature Communications has provided an answer, revealing that the decline of tropical forests locked Earth in a “hothouse state” that prevented it from cooling down.
The trigger for the Permian-Triassic mass extinction was a massive eruption of molten rock in Siberia, which released carbon dioxide into the atmosphere and led to extreme temperature increases. On land, surface temperatures rose by as much as 6°C to 10°C, making it difficult for many life forms to adapt.
However, tropical forests played a crucial role in mitigating these effects by absorbing carbon dioxide from the atmosphere. When these forests disappeared, the efficiency of the organic carbon cycle was greatly reduced, leading to prolonged “super greenhouse” conditions that persisted for five million years.
The study’s findings suggest that when Earth’s climate crosses certain “tipping points,” truly catastrophic ecological collapse can follow. The loss of tropical and subtropical plant biomes is essential to maintaining a climate equilibrium, and their disappearance can contribute to additional climate warming.
This research highlights the importance of understanding past climate change events to better comprehend and prepare for future challenges. By studying the Permian-Triassic mass extinction, scientists have gained valuable insights into the critical role that tropical forests play in regulating Earth’s temperature and mitigating the effects of extreme climate change.
Source: https://www.sciencealert.com/earth-became-a-hothouse-250-million-years-ago-and-we-finally-know-why