At the end of the book the protagonist is the only living being on the new world which looks like "life had never existed". The world "left the dark and cold", and since he saw all people dying which meant something to him and finally is released by death itself he leaves "his tears behind".
Although I think "The Merman's children" being probably the best base for this song it always reminded me of "Elric of Melniboné" - or rather of the last part of the story, where the Chaos is about to take over the world (something that was foreseen by a lot of people, but they couldn't change it). There is even a giant in this part, who falls (= "is lost"), the earth is lifeless and dead ("the desert we called earth") and I don't think there are still whales left in the oceans at that time. Elric has to take the last step from his theater of pain - finally fulfilling his destiny, every step he took before only led him to this final one.
At the end of the book the protagonist is the only living being on the new world which looks like "life had never existed". The world "left the dark and cold", and since he saw all people dying which meant something to him and finally is released by death itself he leaves "his tears behind".