 atmosphere, noting the recent build up of carbon dioxide. Perhaps they are wondering if this change is due to some geological properties of our planet, or if instead it reveals inhabitants who are clever but unwise.
Related Web Pages
Searching for Pale Blue Dots
Handful of Habstars
The (Astrobiology) Canterbury Tales
Looking Down on Opportunity
Ethane Flakes Into Methane Lakes
Jellyfish-Like Creatures Fight Global Warming
Phytoplankton Cloud Dance