On tonight's CBS Evening News podcast, millions of Americans head home from the holiday tonight and it's expected to be the worst travel day of the year. Also, CBS Evening News takes a rare, firsthand visit of an underwater ocean lab off the Florida Keys. The same place where scientists are studying the effects of climate change.See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.