Fossil leaves may reveal climate in last era of dinosaurs

By CHRISTINA LARSON
AP Science Writer

WASHINGTON (AP) — Ginkgo trees have survived as a species virtually unchanged for 200 million years, and patterns on their leaves may help scientists decipher ancient climates. Pores essential for photosynthesis multiply based on the level of carbon dioxide in the atmosphere. So Smithsonian scientists are growing ginkgos today in carbon-controlled greenhouses to see what CO2 levels produce ancient leaf patterns. They have studied ginkgo samples from both the last era of the dinosaurs and the beginning of the Industrial Revolution. Their goal is to better forecast the future by understanding how Earth’s systems responded to dramatic climate changes in the recent and prehistoric past.