Large meteors or comets and high volcanism can cause widespread death {catastrophe, Earth}.
meteor
Large meteor or comet hit 65 million years ago. Iridium level is higher in that rock stratum than in other layers. Iridium is more abundant in space than on Earth. That stratum also has pressure-shocked minerals.
volcanoes
Volcanic activity was high 443 million years ago, 374 million years ago, 251 million years ago, and 201 million years ago. Volcanoes put hydrogen sulfide, sulfur dioxide, carbon dioxide, and methane into air, which cause greenhouse effect and warm air.
ocean
With ocean warming, surface absorbs less oxygen, and chemocline rises. At high enough warming, chemocline comes to surface, and hydrogen sulfide enters air. Hydrogen sulfide kills land animals and plants directly. It also attacks ozone shield, allowing more UV radiation, which kills animals and plants.
Physical Sciences>Earth Science>Planet>Temperature History
5-Earth Science-Planet-Temperature History
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Date Modified: 2022.0224