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How can dust from a giant impact change Earth’s climate?

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The Chicxulub asteroid — Earth impact hazard An artist's rendering of the impact of a near-Earth object 66 million years ago in what is today the Caribbean region. Many scientists think that the collision of a large asteroid or comet nucleus with Earth triggered the mass extinction of dinosaurs and many other species near the end of the Cretaceous Period.

When a giant impact occurs, it can significantly alter Earth’s climate by throwing massive quantities of fine dust and debris high into the atmosphere. This material creates a global haze that blocks incoming sunlight, preventing photosynthesis for years or even decades.12

The resulting reduction in solar radiation reaching the surface leads to a prolonged depression of global temperatures, a phenomenon known as an "impact winter," where temperatures may drop by as much as 28 °C (50 °F). In addition to dust, impacts can vaporize sulfur-rich rocks, releasing hundreds of gigatons of sulfur into the atmosphere. This creates a haze of sulfuric acid, which can further cool the planet by scattering solar radiation and potentially cause acid rain, leading to widespread environmental disruption and mass extinction.123