How Do We Know What Earth's Climate Was Like Long Ago? We Asked a NASA Scientist

How do we know what Earth's climate was like long ago? If you look closely, there are clues just about everywhere across our globe. Some are easy to see and others are more subtle. NASA climate scientist Dr. Gavin Schmidt explains.

Want even more?: https://climate.nasa.gov/faq/20/how-d...

Producers: Scott Bednar, Jessica Wilde
Editor: Daniel Salazar