In the 22nd century AD, the earth inhabited by humans suffered irreversible damage. The glaciers melted and flooded most coastal cities. After so many years, humans still have not been able to find another habitable planet.
So humans built elevating human greenhouses on the former continent. The only 200 million humans left on the earth lingered in the greenhouses. These were undoubtedly the rich and powerful in the past. Those who failed to board the human greenhouses all died in the submerged cities. In the past two years, you could even see densely packed floating corpses on the sea through the protective cover of the greenhouses, including humans and animals. Most marine life is still swimming in the sea.
But those cold water fish have become a drop in the ocean in textbooks.
Purpose: Don't wallow in misery, someone will eventually pull you out of the darkness