(i) These areas are too rugged.
(ii) Too hot and too cold.
(iii) Settlement is difficult because Central Asia have rugged relief.
(iv) Inhospitable forests, deserts or mountainous regions.
Though China is the most populous country with 1222 million people in 1994 has reduced its birth rate in recent years. The annual growth rate of population is only 1.3 percent. India the second largest populous country in the world and has a growth rate of population about to 2.5 per cent per year.
Rapid growth of population causes environmental degradation, because biological needs of growing population are to be fulfilled. Environmental degradation is caused due to deforestation (felling of trees), soil erosion and fall in water supply.
This results in gradual decline in yields of grain. Some of the developing nations are facing drought and famine conditions. These countries need food aid and economic assistance because they are not economically fit to import essentials.
Absence of such external aid increases death rate due to malnutrition & various diseases. This is happening in certain parts of Africa.
Certain developing nations of Asia and Latin America are on the path of economic development due to spread of education especially among women: They are also getting external aid. This has resulted in low birth rate. It is hoped that these nations will achieve low birth rate in a few years. This will lead to stable population growth in a few decades.