The asteroid that killed the dinosaurs also baked Earth for 100,000 years. By analyzing tiny fish bones and teeth, researchers determined global CO2 levels reached 2,300 ppm following the impact. For comparison, CO2 levels recently climbed above 410 ppm for the first time in millions of years.

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The asteroid that killed the dinosaurs also baked Earth for 100,000 years. By analyzing tiny fish bones and teeth, researchers determined global CO2 levels reached 2,300 ppm following the impact. For comparison, CO2 levels recently climbed above 410 ppm for the first time in millions of years.