Fossils Offer Clues about Warmer World

More than 55 million years ago the Earth underwent a period of global warming caused by increased levels of carbon dioxide. Doctoral candidate Rosemary Bush (G09) is studying plant fossils from the Big Horn Basin in Wyoming to understand how plants responded to the relatively short period of warming. Bush grinds up fossilized leaves to look at the isotopic abundance and composition in their biomarkers to track changes in past ecosystems. “If we can understand how plants responded to climate change in the past,” Bush says, “maybe we’ll have a snowball’s chance of understanding how they’ll respond in the future.

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