IIRC these «dykes» have (had) been build in 2008, when it became quite clear that due to the massive ice retreat the coast line was in direct danger from August on... (neven1.typepad.com)
But Dr. Ball is quick to point out how the world was in direct danger if we had not implemented the Montreal Protocol. (ecoshock.org)
Further on we see his conflict with Tim where he winds up locking Tim away, ultimately putting him in direct danger, yet another failure of Bruce that results from his more human side. (wolfsgamingblog.com)