Arctic Clouds Key to Modeling Eocene Paleogene Greenhouse Climate

Fifty million years ago, the Cowboy State was crawling with crocodiles. Fossil records show that crocs lounged in the shade of palm trees from southwestern Wyoming to southern Canada during the Cretaceous and Eocene. Exactly how the middle of the North American continent -- far from the warming effects of the ocean -- stayed so temperate even in winter months has long eluded scientists.

In recent decades, researchers have observed those same high-latitude regions in North America and Asia warming much faster than the rest of the world.

New work by researchers at Harvard John A. Paulson School of Engineering and Applied Science (SEAS) and the Harvard University Center for the Environment (HUCE) suggests that increased amount of low clouds in the Arctic, due to rising Arctic temperatures, could amplify winter warming in high-latitude regions. This mechanism offers a possible explanation to both past and future continental warming in winter.

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