This is a preview of our upcoming episode of COSMIC JOURNEYS. Look for it in mid-October. It’s an ambitious attempt to explore the relevance of major past climate change to today. In particular, we look at the last interglacial, the Eemian, when sea levels rose to somewhere between four and eight meters higher than today. Interestingly, temperatures were only modestly higher than today and carbon dioxide levels were substantially lower. That’s an example of the many twists and turns in the tangled history of our dynamic planet.