Is it possible for human beings to survive under the sea or underground in the future?

It is possible to live underground or in the sea. If the depth is shallow, there is no need to wait for the future. Now there are scientific research facilities underground or in the sea where workers are stranded for a long time. However, as a living environment, underground or underwater is not an ideal living environment, and there are either health problems or risk problems such as collapse accidents.

Different from scientific research and life-threatening work, large-scale group life needs an ideal living environment. If you are a community leader, I hope your community lives in an underground or underwater city. In the event of an accident, the survival rate of all of you is slim. Would you be willing?

Of course, if life on the surface is difficult, underground or underwater will be a more realistic solution than moving to other planets.