What causes volcanic winter?

A volcanic winter happens when a big volcano erupts and covers the sky with ash, making it cold for a long time.

When a volcano erupts, it sends up ash, tiny pieces of rock and glass, into the air. This ash can go very high, even into the atmosphere where clouds live. Once there, it blocks some of the sunlight from reaching Earth. It’s like putting a blanket over the sun.

Without as much sunlight, Earth doesn’t get as warm. Think about when you're outside on a cloudy day, it feels cooler than when the sun is shining brightly. A volcanic winter is kind of like a very long, very cloudy day. The ash stays in the air for months or even years, so the cold lasts a lot longer than a regular cloudy day.

Sometimes, this can make plants and animals struggle, just like how you might feel chilly if you forget your jacket on a cool day.