There’s a brand new project on the Zooniverse – Fossil Atmospheres
Researchers at the Smithsonian’s National Museum of Natural History in Washington, D.C. need your help to track climate change over millions of years! 
Ginkgo trees evolved before the dinosaurs, survived three mass extinctions, and one species is still living today. They are researching how the cells of leaves on ginkgos have changed over time, and whether they can use them to learn about the ancient atmosphere of the Earth.