Earth, 2971
The water rose by an unpredictable amount due to climate change. The Earth's surface froze over, and humans were forced to live underwater, where they could still harvest energy and grow food.
As resources began to dwindle in the year 2971, sub-aquatic spaceships were sent to a nearby wormhole to look for habitable planets. Things did not go as planned. And now the ship Argo9 has returned, thousands of years later…