This episode focuses on the methods that scientists have used to figure out Earth's climate history, as well as provide a timeline of what happened to the climate throughout history. 

Sources 

• Silver, Jerry. Global Warming and Climate Change Demystified. McGraw-Hill, 2008.
• Stevens, Fisher, director. Before the Flood. National Geographic Documentary Films, 2016.
• Herman, Gail, et al. What Is Climate Change? Penguin Workshop, an Imprint of Penguin Random House, 2018.
• Riebeek, Holli. “Paleoclimatology: A Record from the Deep.” Earth Observatory, NASA, 27 Sept. 2005, earthobservatory.nasa.gov/features/Paleoclimatology_SedimentCores/paleoclimatology_sediment_cores_2.php.