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How can dust from a large asteroid impact affect the atmosphere and climate?

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Wispy cirrus clouds stretch across a bright blue sky above trees and a river at Pinawa Dam Provincial Park in Manitoba, Canada, with sunlight illuminating the scene. — Atmosphere The atmospheres of planets in the solar system are composed of various gases, particulates, and liquids. They are also dynamic places that redistribute heat and other forms of energy. On Earth, the atmosphere provides critical ingredients for living things. Here, feathery cirrus clouds drift across the deep blue sky over Pinawa Dam Provincial Park, near Pinawa, Manitoba, Canada.

When a large asteroid impacts Earth, it can inject massive quantities of dust and debris into the atmosphere, specifically reaching the stratosphere. These particles remain suspended for extended periods, significantly decreasing atmospheric transparency and blocking sunlight from reaching the surface.1

This reduction in solar radiation can persist for months or even years, leading to profound cooling of the global climate. Such dramatic environmental shifts are believed by many scientists to have been a primary driver of the mass extinction of species that occurred at the end of the Cretaceous Period approximately 66 million years ago. While smaller impacts occur more frequently, these catastrophic events are rare, though they represent a significant Earth impact hazard.12