https://www.technologyreview.com/s/610886/if-we-werent-the-first-industrial-civilization-on-earth-would-we-ever-know/?fbclid=IwAR2LQMdzALXgoOoIjba9gthfOOG3l4JHdkHQytv3WfHz3y5oRJWCc8InLd8
Fossils and objects are unlikely to survive more than a few million years. Searching for chemical traces of industrialization offers an intriguing alternative.