Britannica Sources used in this answer

What environmental effects followed the Chicxulub impact?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Illustration showing various dinosaur species drawn to scale and grouped by geologic era: Late Cretaceous, Early Cretaceous, Jurassic, and Triassic. Dinosaurs range from large species like Brachiosaurus and Tyrannosaurus to smaller ones like Velociraptor and Compsognathus, with a human silhouette included for size comparison. Measurement bars at the bottom indicate 1 meter and 3 feet for scale reference. — dinosaur A selection of dinosaurs grouped by the geologic interval in which they lived.

The Chicxulub impact, which occurred approximately 66 million years ago, triggered a series of catastrophic environmental changes that contributed to a mass extinction event, eliminating about 80 percent of all species, including the dinosaurs.123

Key environmental effects included:

Atmospheric Disruption: The impact ejected massive quantities of rock debris and dust into the atmosphere, enshrouding Earth in darkness for months or even years. This global cloud blocked sunlight, causing photosynthesis to cease and leading to the collapse of food chains.234
Extreme Temperature Fluctuations: Global temperatures are estimated to have dropped by as much as 28 °C (50 °F) due to the lack of sunlight.3
Acid Rain and Ocean Acidification: The impact vaporized sulfur-rich rocks, releasing hundreds of gigatons of sulfur into the atmosphere. This created a haze of sulfuric acid, resulting in acid rain that altered the chemical composition of the oceans.3
Fires and Tsunamis: The collision triggered widespread wildfires within a 1,450-km (900-mile) radius and sparked further fires globally via ejected molten rock. Additionally, an enormous tsunami caused significant destruction along coastlines.32