Drastic changes in climate have occurred many times in Earth's history. There is direct fossil evidence of global cooling that took place 35 million years ago, when a tropical climate shifted to a temperate one.
Natural World: Goshen Fossil Bed
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Drastic changes in climate have occurred many times in Earth's history. There is direct fossil evidence of global cooling that took place 35 million years ago, when a tropical climate shifted to a temperate one.