 The human population of the world is unhumanely distributed over the earth's surface. So here we have certain factors which are controlling the distribution of the human population. One of the factors is climate, second is relief feature, third is location and the other areas are also very important in the form of factors. But these are the major factors which are controlling the human population distribution. Why climate is important? Because of the activities. Human activities related to production and services are located in those areas where the climate is suitable. We have example of Pakistan. The Pakistan's economy is controlled by agriculture because the climate and certain other physical factors like soil which is suitable for agricultural area are available for the human activities. So that's why we have human cluster there. So second important factor is the location. The location if that country is located closer to the water body, that factor is also very important because most of the trade activities and the things which are related with the regional or global level, that location is very important. The third one which is the area where we have the factor of the distribution of the human population is the relief features. The plains are suitable for human settlement as compared to the mountainous regions. Desert is not suitable because of the climatic conditions not good there. So these are the areas where we can discuss a lot of things. Now the earth human population at the beginning of the 20th century stood at about 1.5 billion. So this is the beginning of the 20th century where the human population was 1.5 billion. But by the end of that century it exceed 6 billion population. Now why because of the certain things which are favourable for the human growth or human population's growth, some factors are involved. In which you can say that with the change of technology, we have the example of the medicine. After that, life saving drugs, the things which are life saving, serilated medicine were the market. So then you have the growth which is actually in the human population. This slide shows the major clusters of the human population. Again, the latitudinal extent is an important factor. As we are going north or south, the human population is decreasing. Because these are the areas where we have the below freezing temperature. So it is one of the factors that the things are not suitable for the human clusters. And most of the clusters are present in those regions where we have the agriculture land. Like example, we have a China, then we have South Asia and the areas which are closer to the middle attitude where rainfall is available. The things which are closer to the sea sites, the sea sites, i.e. the water body and the Europe which is actually controlled by the coal mining. That is why we get human clusters here. So some are actually controlled by the resources. There were mining resources, there were power sources where fossil fuels are available or metals are available. So the human cluster is present there. So those are actually the factors which are important for the distribution of the human population. But all clusters are unevenly distributed. We have example of China, which is a vast area. If we look at all of China, then most of the region is under less than 20% per square kilometer population. But the 50% area is densely populated area because of certain opportunities and the suitability. During the 1960s and 1970s, the rate of population growth increased so fast that disasters seemed to lie ahead in the form of mass famines and global social dislocations. Since then, technologically advancement have expanded food production even faster than the population has grown. And the global population growth rate has begun to slow. But as we will see, the problem resulting from the population explosion still prevailed. Hundreds of millions of people, mostly children, remain malnourished. Many countries, mostly in the poorer part of the world, continues to have population increase with which they cannot cope. So the human population increased from 1950 to onward. Now today it is closer to the 7 billion population. Why? Because of the certain opportunities or the things which are favorable to the human growth. This may be medical sciences, genetic engineering, technology, the flow, the economic condition. So the population nowadays is closer to the 7 billion. Now here we have certain stages which are important for the growth of the world population, human population. But it is actually controlled by natural increase. What is natural increase? Natural increase is actually the birth rate and the death rate. If we are studying the crude birth rate with crude death rate, that is actually the part of the natural increase. Now in stage 1, when pre-industrial era, the growth of the population was very slow. Because the level of technology was low and there was no awareness. In the second stage, in the early industrial era, rapid growth, i.e. people in awareness society and transportation networks, communication networks, we see that the birth rate of the population was similar but the death rate was less because some life-saving drugs were marketed. In the third stage, we see that the sudden decline in the birth rate because the industrial stage was matured and the population growth was slow. Because the availability of the market was rising and the birth rate was less. In the fourth stage, the post-industrial era has become more slow because we are passing through nowadays the post-industrial era. Now in this part of the world, we have the developed economies where the population growth that is closer to the zero and the developing economies have also become less. We have example of India, we have example of China and again in Pakistan which is closer to the 2.1% annual growth percentage in the growth rate. So why because of the education, it has played an important role for the reduction in the birth rate. So the focus of the study of the population geography is on the spatial aspect of demography. Demographic issues and problems vary not only region to region but country to country. This demography is the main characteristics of the population. We call the study of demography and its issues vary from region to region. As I said, the developed world is a region and the developing world is a region and country to country. If we compare Pakistan with Afghanistan, the demographic characteristics are different because of the cultural differences, because of the economic differences.