1) With the modern level of science there is a possibility to make a life under the ground. While living under the ground people can easily be supplied with neccesary products, such as food, water, and other life-important stuff. Under the ground life can be required first of all because of the disasters, so that is one of the ways people can save themselves, furthermore people use under the grond life as a saferoom because of nuclear threat, that is why under the ground life is given a big attention .2) First of all it is a type of ground. There can be quicksand, the movement of the lithospheric plates, or under the ground water streams, that also make the building much harder. On the other hand there can be economical problems, for example, poeple could not be interesting in building under the ground cities, and there just wont be enough money to build it.3) Firstly, I think, it is a psychological problem, as it is very difficult to get along with the new surroundings, in this case you feel, that there is only ground around you, people can get crazy, or be scared. Another problem it is the lack of sunlight, as people need the sunlight for their health, in other case they can get different sicknesses.4) Sure I do. The government should build another cities that can bring some interest to people, for example cultural centers. As modern science constantly develops, soon there will be new levels of technologies that will allow avoid the greenhouse effect, mainly caused by cars and machines.
