A nation must be considered overpopulated when it is unable to provide for this population at the level on which they insist except by seriously degrading its natural and agricultural heritage, including forests, coastlines and coastal waters. An overpopulated country is not necessarily a crowded one.

Australia has one of the lowest population densities in the world. With a low population of 23 million and a land area of over 7.6 million km² its density is around 3 people per km².

Canada is under-populated because it has an advanced industrialised economy and so many valuable natural resources that it could easily provide extra people with a high standard of living.

Global population growth will decelerate markedly over the coming generation. By current projections, in fact, slightly fewer babies will be born worldwide in the year 2025 than at any point over the previous four decades. Thanks to extreme birth dearth, depopulation is now imminent for both Europe and Japan.

Answer: Disadvantages of over population: Poverty, hunger, lack of spaces, illiteracy, development of slums and over exploitation of natural resources.

The Japanese Statistics Bureau (pdf) estimates that the Japanese population will fall to just over 100 million by 2050, from around 127 million today. The United Nations estimates that Japan’s population will decline by a third from current levels, to 85 million, by 2100.

While this table contains some old data, it is clear that Japan is very safe when compared with other countries. There are only 0.99 cases in Japan for 51.04 in England and Wales, with 38.55 cases in the United States, and 20.12 in France.