New Study Suggests Global Wildfires, Not Cold, Caused Dinosaur Extinction
A recent study proposes that the extinction of dinosaurs 66 million years ago was primarily caused by global wildfires, triggered by intense heat radiation from an asteroid impact, rather than a prolonged cold period.
New research challenges the long-held theory that dinosaurs perished due to a harsh, years-long winter following an asteroid impact 66 million years ago.
Instead, scientists now suggest a more devastating scenario: massive global wildfires, ignited by intense thermal radiation from the impact, may have rapidly incinerated much of life on Earth.
The asteroid, which formed the Chicxulub crater in Mexico, vaporized vast amounts of rock. This vapor condensed into molten particles called spherules that rained down, and also formed a fine silicate dust layer in the upper atmosphere. This dust layer acted like a blanket, trapping heat.
Researchers estimate this dust layer increased surface thermal radiation by up to 3.5 times, a level intense enough to kill most exposed life within hours. This heat likely ignited vegetation, leading to widespread fires. Following this initial heat blast, the dust could have caused a prolonged impact winter, completing the extinction.
The study, published in JGR Biogeosciences, points to fossil evidence in North America. However, scientists acknowledge the need for more global evidence of widespread wildfires to fully support the theory.