There SHOULD be an Earth flag, with or without an anthem. Maybe it would be the first teeny baby step towards people feeling like the whole planet it a community. It could eventually lead to bigger steps to help us be neighbors rather than enemies or anyway strangers.
I’m ashamed to think about an anthem though.
Earth we love you we really do,
Even though we use up your gifts,
And coat you in filth,
We remain ever loyal to our darling plaaaaaanet.