The impact of population on the environment

With the increase of population and the progress of science and technology, on the one hand, great progress has been made in using the environment and conquering nature, but at the same time, some serious problems have been brought. This is the ecological crisis that is often learned from the news media at present. This is because people have lost control of their own development and the environment has been destroyed. The severity of destruction has affected human beings and threatened the continued existence of many other species. Many scholars who care about the living environment of human beings are deeply disturbed by this amazing fact. They loudly ask people to control themselves in order to maintain the balance between themselves and the ecological environment. Although they also realize that there are many reasons for this crisis, it is very important to reduce the population growth rate and reduce the pressure on the environment, otherwise the environmental situation will continue to deteriorate.

The population, that is, the population density of an area, is closely related to the environment. Since the Middle Ages, the change of vegetation in Central and Western Europe is a good example. In the past, farmers living in plains and valleys cut down forests, turning relatively flat areas into fertile farmland and forming densely populated agricultural areas. However, between the edge of the agricultural area and the agricultural area are hills and low mountains, where dense forests grow and are preserved because they are not suitable for farming. Because forest vegetation is closely related to hilly terrain, people living in hilly areas of Central and Western Europe often regard the word forest as a region with rugged terrain. The expansion and contraction of forest area in this area is closely related to the increase and decrease of population. During the period of war, epidemic disease and famine, the population decreased, and the forests on the hills expanded to low-lying and plain areas; During the period of social stability and population growth, the forest area will shrink. 1337- 1453, the century-long war between Britain and France greatly reduced the population and greatly expanded the forest area. In France, there is a saying among farmers: "The British brought the forest to France". This is also the case in the northeastern United States. After the first immigrants arrived, they cut down forests and cultivated farmland. At that time, agriculture developed at the speed of deforestation, so that a large area of forests disappeared. However, since the 20th century, many farmers have left the countryside and turned to cities, and the forest has also expanded to farmland, and the forest area is gradually expanding.

The above example is only the relationship between the change of population and production mode and the growth and decline of forest area, and there is no major change in the forest environment that affects its own survival. In Cuba, the Spanish burned forests as fertilizer to grow coffee for profit, which led to more serious consequences. They didn't expect the heavy rain to wash away all the bare soil without forest cover, leaving only bare rocks. Not only can coffee not grow, but the forest is also difficult to recover.

The consequences of human destruction of forests are serious, and grasslands are also affected by human activities to a considerable extent. Some evidences show that since the Roman period, the area of the desert has gradually expanded due to overgrazing on the short grass grassland on the edge of the Sahara desert. There is a similar situation in China, and some deserts in southern Inner Mongolia are also caused by unreasonable reclamation in history. In the past, it was often said that "the desert moved south" was actually improper large-scale reclamation in some places, which contributed to the expansion of desert area.

The above examples fully show that population growth has brought heavy pressure on the environment and led to a serious ecological crisis. In fact, this conclusion is not entirely correct. In terms of people's consumption, the living standards of people in industrialized countries are relatively high, and they consume much more materials than those in developing countries. For example, per capita energy consumption in the United States 10 ton/person-year (1980) and meat consumption 108 kg/person-year. This figure is not several times or ten times higher than that of developing countries, but dozens of times. Generally speaking, the population of the United States accounts for about 5% of the world population and consumes about 40% of the world's resources every year. Therefore, every additional person in the United States will have a much greater impact on the world environment than every additional person in developing countries.