Dinosaur Extinction: Volcanoes Finally Ruled Out?

In a breakthrough study published in Science Advances, climate scientists from Utrecht University and the University of Manchester have brought fresh clarity to a long-standing debate: What truly ended the reign of the dinosaurs? While massive volcanic eruptions on the Indian peninsula once seemed a likely culprit, the new evidence points squarely to the Chicxulub meteorite impact as the ultimate cause.

Researchers analyzed fossilized molecules preserved in ancient peat deposits from the United States. These bacterial biomarkers, whose structures shift with temperature, allowed the team to reconstruct a detailed “temperature timeline” of Earth’s climate around 66 million years ago. Their findings show that a significant volcanic eruption occurred about 30,000 years before the meteorite impact, cooling the climate by nearly 5° Celsius as volcanic sulfur emissions blocked sunlight. However, the cooling was only temporary. By roughly 20,000 years before the impact, temperatures had rebounded to levels similar to those before the volcanic events began.

The meteorite impact near the Yucatan Peninsula triggered a cascade of disasters—wildfires, earthquakes, tsunamis, and a prolonged “impact winter” that devastated ecosystems. In contrast to the earlier volcanic phase, this singular, cataclysmic event appears to have been the primary driver behind the mass extinction that wiped out the dinosaurs.

This study not only tilts the scales in favor of the meteorite impact theory but also highlights the power of molecular fossils in decoding Earth’s climatic past. As scientists continue to refine these techniques, new insights into other pivotal moments in our planet’s history are sure to emerge.