Well, according to them it can only echo for 12 years.
They’ve cried wolf - “12 years til the end of the world” - for decades.
U.N. predicts disaster (by 2000) if global warming not checked - June 29 1989, Peter Spielman
https://www.apnews.com/bd45c372caf118ec99964ea547880cd0
UNITED NATIONS (AP) _ A senior U.N. environmental official says entire nations could be wiped off the face of the Earth by rising sea levels if the global warming trend is not reversed by the year 2000.