it's not literal. we're in a mass extinction that's only going to get worse. earth as shorthand for the environment that supports all these creatures (including us).
This is also misleading. What's disappearing is a sustainable environment suitable for humans without advanced technology and globalized trade.
Humans are living in climate-controlled environments in Phoenix, but they wouldn't last long without (fossil-fuel based) external energy sources. Or at least there wouldn't be that many.