Talk about the social problems caused by the rapid growth of the world population.

Excessive population growth will not only cause traffic jams, poor living conditions, employment difficulties, hunger and poverty, but also cause a series of problems such as increased environmental pollution, deterioration of ecological environment, reduction of various land resources such as forests, grasslands and cultivated land, and natural resources such as water resources and mineral resources (especially the sharp decline in per capita ownership).

1. Grain production

From 1950 to 1984, the growth rate of world grain output far exceeded the growth rate of population, but since then, the growth rate of grain output has lagged behind the growth rate of population. According to the statistics of the United States Department of Agriculture, the per capita grain output has decreased by 7% (0.5% per year). Since 1984, the growth rate of world grain output has slowed down, because of the shortage of new cultivated land and the decrease of irrigation.

Because agriculture has reclaimed undeveloped arable land, the increase of grain output in the future will almost completely depend on improving the productivity of existing land. Unfortunately, it's getting harder and harder. When the per capita arable land is reduced, the per capita irrigation amount is reduced, and the crop yield is reduced due to excessive use of chemical fertilizers, the world agriculture is facing the challenge of reversing this decline.

2. Cultivated land

Since the middle of this century, the grain production area-usually synonymous with cultivated land-has increased by 65,438+09%, while the world population has increased by 65,438+032%. Population growth degrades cultivated land, reduces output and even uses it for other purposes. With the decrease of per capita grain area, more and more countries are in danger of losing their self-sufficiency in grain.

The situation of the four countries with the fastest population growth in the world is very obvious. He explained this development trend. 1960- 1998, the per capita arable land in Pakistan, Nigeria, Ethiopia and Iran decreased by 40-50%. It is predicted that it will be further reduced to 60-70% by 205O, which is only a conservative estimate under the assumption that cultivated land will not be reduced. In this way, the total population of the above four countries will be above 1 100 million, while the per capita cultivated land area is only 300-600 square meters, which is less than 1/4 of the per capita cultivated land area in 1950.

3. Fresh water

The expanding shortage of water resources may be the most neglected resource problem in the contemporary world, but in areas where the population is still growing, the per capita fresh water supply is decreasing.

The dryness of rivers and the decline of groundwater level are considered as evidence of water shortage. For example, the Nile, Yellow River and Colorado River are almost empty. At present, the groundwater level in all continents of the world, including major grain-producing areas, is declining, and the groundwater aquifers in the southern Great Plains of the United States, the North China Plain of China and most parts of India are increasingly exhausted.

The International Water Resources Management Institute predicts that in 50 years, some countries with a population of about 654.38 billion will face absolute water shortage. These countries will definitely reduce agricultural water consumption to meet the water demand of residents and industries. China and India are two big irrigated agricultural countries in the world, which will greatly reduce irrigation water consumption.

4. Marine fishing

Since 1950, the human intake of seafood has increased by five times, making the catch of most fishery resources reach or exceed its tolerable limit. Marine biologists believe that the annual catch of global marine waters cannot be much higher than 93 million tons.

At the end of the 20th century, overfishing has become a common practice, and it is no exception. Among the 65,438+05 major marine fishing areas in the world, 65,438+065,438+0 fishing grounds have lost their catch. Atlantic cod has been the main food for western Europeans for a long time, and its catch has dropped by 70% from the peak of 1968. Starting with 1977.

With the depletion of marine fishery resources, the demand for seafood in the future can only be met by aquaculture. When the world turned to aquaculture to meet the demand, fish began to compete with livestock and poultry for feed, such as grain, soybean meal, fish meal and so on.

In the first half of the next century, some species will probably become extinct in the world, and the quality of the caught seafood will also decline, but its price will remain high, and the contradiction between countries competing for fishery resources will intensify. Compared with the highest per capita catch of 65,438+0,988 (65,438+07.2 kg (37.8 lbs)), the annual per capita catch in the future will decrease by roughly the same amount with the population growth, and will drop to 2050.

5. Meat products

In some traditional low-wage people, when people's income begins to increase, they should first diversify their diets, which requires more animal products.

Since 1950, the growth rate of meat products in the world is almost twice that of population. The growth of meat products was initially concentrated in western industrialized countries and Japan, but it has also increased rapidly in East Asia, the Middle East and Latin America in the past 20 years. Beef, pork and poultry account for the vast majority of the world's meat consumption.

According to the statistics of the United States Department of Agriculture, it is estimated that 37% of the world grain output 1998 187 billion tons will be used for raising livestock and poultry and producing milk, eggs and meat products. Now, grain is used to feed poultry and livestock, which is the main grain reserve in the case of world food crisis.

It is predicted that the total consumption of meat food in the world will increase from 65,438+2110 million tons in 1997 to 51300,000 tons in 2050, and the pressure on world food supply, environment and resources will increase.

6. Nature reserves

From Buenos Aires to Bangkok, the population growth of major cities in the world is amazing, which leads to the unplanned expansion and pollution of cities and threatens the nature reserves around the urban areas. In all continents of the world, human encroachment not only reduces the scale of nature reserves, but also reduces their quality.

In countries where the rapid population growth exceeds the carrying capacity of local natural resources, protected areas become particularly vulnerable. Although in industrialized countries, protected areas are synonymous with camping, picnics and country picnics, most national parks, forests and protected areas in Asia, Africa and Latin America have always been inhabited by local people or used for natural resources.

In many industrialized countries, the growth of immigrant population also endangers nature reserves. For example, as millions of new immigrants move to western Florida, Everglades National Park will be in danger of being destroyed.

It is like the tip of the iceberg that a large number of long-awaited immigrants move to a scenic spot where the cost of a few immigrants is high. With the increase of immigrant population, the current calm and tranquility of the reserve will be broken, and the rich and colorful natural environment and human landscape will disappear.

7. Forests

Compared with most periods of human history, the global forest area decreases with the increase of population. However, in the 20th century, the global forest area decreased by about 75%.

In Latin America, grazing is the single most important reason for deforestation. In addition, overgrazing and excessive firewood collection-usually caused by population growth-have degraded 65,438+05% of the world's vast virgin forests.

Tracing back to the deforestation caused by wood demand in recent ten years, it is closely related to the increase of per capita wood consumption. Since 196 1, the number of paper and paperboard per capita in the world has doubled.

The reduction of forest area leads to the decline of forest functions, including the living environment of wildlife, carbon storage (the key to regulating climate), soil erosion control, water storage across rainy and dry seasons, and rainfall regulation.

8. Biodiversity

In modern human life, species disappear at a natural rate of 100 ~ 1000 times, which is the largest period of animal and plant extinction since the extinction of dinosaurs at the end of Yum! 65 million years ago. The root cause of species extinction is that the increase of population density leads to the deterioration of the natural environment in which animals and plants live.

The natural environment in coastal areas is particularly suitable for biological reproduction, but it is also very fragile. More than 60% of the world's population lives in this area. For example, coastal wetlands breed two-thirds of the world's commercially caught fish, and the biodiversity density of coral reefs ranks second in the world after tropical rainforests. However, the gradual invasion of human beings and its pollution have made the environment in coastal areas worse and worse: it is roughly estimated that the salt marshes and mangrove swamps in 1/2 of the world have disappeared or been completely changed, and two-thirds of the coral reefs in the world have been degraded, among which 10 arc is "unrecognizable". As the coastal migration continues-in less than 30 years, coastal residents may account for 75% of the world's population-the environmental pressure they generate is possible.

9. Climate change

In the past half century, the growth rate of carbon emissions from fossil fuel combustion is almost twice that of population growth, which makes the concentration of carbon dioxide, the main greenhouse gas in the atmosphere, increase by 30% compared with the pre-industrial period.

The carbon emissions of fossil fuels account for about 3/4 of the total carbon emissions in the world. Therefore, where the economy is active and the corresponding energy consumption grows fastest, regional carbon emissions tend to increase. As China's fast-growing economy relies heavily on coal and other carbon-rich energy resources, it is predicted that the growth rate of carbon emissions in China will be three times faster than the population growth rate in the next 50 years.

According to the government's estimation of the Subcommittee on Climate Change and the US Department of Energy, the carbon emissions of developing countries will triple in the next half century, while those of industrialized countries will increase by 30%. Although the annual carbon emissions of industrialized countries are still twice that of developing countries, by 2020, the latter will surpass the former.

10 energy

In the past 50 years, the growth rate of global energy demand is twice that of population. By 2050, developing countries will consume more energy due to the increase of population and the affluence of life.

When the per capita energy consumption remains high, even if the population growth rate is very low, it may have a significant impact on the total energy demand. For example, by 2050, it is estimated that there will be 75 million new people in the United States, and its energy demand will increase to about the sum of current energy consumption in Africa and Latin America.

The world's per capita oil production reached the highest level in 1979, and then decreased by 23%. It is predicted that global oil production will reach the highest limit by 20 1 1 in 2025, which indicates that as long as oil remains the leading fuel in the world, oil prices will still rise sharply in the future.

In the next 50 years, the region with the largest increase in energy demand will be the most economically active region: in Asia, although the population growth is only 50%, energy consumption will increase by 36 1%. In Latin America and Africa, energy consumption is expected to increase by 340% and 326% respectively. The above three areas are facing great pressure from energy resources such as forests, fossil fuel reserves and water resources.

1 1. Waste

Because the world's new population will reach 3.4 billion in the next half century, the impact of waste discharge on the regional and global environment is likely to be more serious, and the hope of providing an available sanitary environment in the near and medium term is very slim.

The growth of population has increased the trouble of social garbage disposal-garbage, sewage and industrial garbage must be disposed of. Even in areas where the population is basically stable, the waste in many industrialized countries is usually increasing. In the next few decades, many developing countries will have rapid economic development and rapid population growth at the same time, and the mountainous garbage that is difficult to handle is likely to challenge the city and state management agencies. Economy will affect the quality of life.

12. Employment

Since 1950, the world labor force population has increased by more than 1 100 million-from10.2 billion to 2.7 billion-faster than the growth rate of employment creation. Future population growth will increase the demand for labor (through economic activities and commodity demand), which will certainly promote labor supply. When the population growth makes the supply and demand of labor force unbalanced, wages will be excessively reduced, and the workload will not increase because of the surplus labor force.

Since today's children are tomorrow's workforce, the interaction between population growth and employment is most sensitive in countries with a large number of young people. Countries with more than half of the population under the age of 25, such as Poland, Mexico, Indonesia and Zambia, will feel the importance of this labor tide. In addition to giving people a sense of self-esteem and self-reliance, employment is also the key to obtaining food, housing, medical services and education.

13. Income

In developing countries and regions with the largest population decline, income growth is the fastest, including South Korea, Taiwan Province Province of China, China, Indonesia and Malaysia. Most African countries that neglect family planning are troubled by a large number of young people who really need education and employment.

If all countries in the world can't turn their economies to the track of environmental sustainability and low population growth at the same time, economic recession will be inevitable.

14. House

The final result of population growth exceeding housing supply is that some people can return to their homes. According to the estimation of the United Nations, there are at least 654.38 billion homeless people in the world, which is roughly equivalent to the population of Mexico. Including squatters and other unsafe or temporary residences, the total number of women is as high as 654.38 billion.

If the global population growth cannot be controlled, the number of homeless people may increase alarmingly.

education

In countries where the proportion of children's age population is increasing, the basic pressure on educational institutions will be heavy. Most of the 10 countries with the fastest population growth in the world are in Africa and the Middle East, and their child-age population will increase by 93% on average in the next 50 years. By 2040, the school-age population in Africa will increase by 75%.

If educational organizations in various countries begin to emphasize lifelong learning in view of the rapid changes in the world in the 2 1 century, then adult education needs to be widely carried out, even affecting those countries with decreasing child populations.

16. City

Modern cities have developed rapidly: the permanent population of London has increased from 6.5438+0.30 million to 8 million in the past 654.38+0.30 years, while Mexico City has achieved this leap in only 30 years. In short, the world's urban population is increasing at a rate of1100,000 per week. The growth of urban population, including the natural growth of urban population, the migration of rural population and the expansion of villages and towns, is absorbed by the expansion of existing cities.

If the current urban population growth momentum continues, 6.5 billion people will live in cities by 2050.