What is the population of the earth? What is the area? What's the population of America? What is the area? What's the population of China? What is the area?

In the past two hundred years, the world population has increased faster and faster. 1830 The world population exceeded 10 billion, and the world population increased from the first 10 billion to the second 10 billion used 100 (1830 ~ 1930) After that, it took only 30 years (1930 ~ 1960), and the world population jumped to 3 billion. Then after 15 years (1960 ~ 1975), the world population reached 4 billion. After 12 years (1975 ~ 1987), the world population exceeded 5 billion. From 65438 to 0999, the world population reached 6 billion.

There are more and more people, but there is only one earth. Many people are worried about the ability of the earth to carry people.

Joel E.Cohen, an American demographer, published a monograph "How many people can the earth support" in 1996, summarizing the research on the earth's carrying capacity in the past 400 years. Up to now, as many as 65 evaluation reports have been published. The difference between these two estimates is amazing, from the lowest less than 654.38+0 billion to the highest over 654.38+0 trillion.

In contrast, Chinese scholars' estimation of China's population capacity is relatively conservative. As early as before liberation, some scholars in China suggested that the total population of China was 400 million. 1948 Some people even suggested that 200 million is the best. It is the first time that Mr. Sun Benwen clearly put forward and demonstrated the population development goal of "How many people should there be in China". 1957 published "800 million population is the most suitable population in China", which became the pioneering work of China's moderate population research. Later, many scholars studied this hot issue, including Tian Xueyuan, Chen Yuguang, Song Jian, Song Zicheng, China Academy of Sciences Natural Resources Comprehensive Investigation Committee, Hu Angang, Cao Mingkui, etc. Have come up with their own conjectural data. Except Hu Angang, who seriously considered the population structure itself, other scholars basically speculated from the perspective of earth resources (such as food and fresh water). The most ridiculous thing is the opinion of Li Xiaoping, Institute of Population Studies, China Academy of Social Sciences. He thinks that the population of China should drop to about 300 million in 200 years. I have refuted this fallacy in Xinhua News Agency's International Herald TribuneNo.18 (published on June 5, 200418). Song Jian had the greatest influence on the population development in China, because his population cybernetics was the theoretical basis of strict family planning in China since 1980s. 198 1 year, Song Jian and others came to the conclusion that the moderate population of China should not exceed 700 million, and 700 million was regarded as the ultimate goal and the best plan of population development in China.

At present, the so-called1600 million population ceiling is the conclusion reached by the Family Planning Commission on the basis of synthesizing the opinions of many scholars: the maximum population capacity in China is about1500 million or about1600 million, and exceeding1800 million to 2 billion may cause a disastrous blow to China's social and economic development (Chen Wei/Meng China Study on Population Capacity and Moderate Population). See how much labor and land were needed to support the same people at that time. Now and in the future, many people will be able to get rid of the land and engage in industrial production. If hybrid rice, plastic film and plastic shed were not popularized in Yuan Longping 30 years ago, a large number of farmers would still be tied to the land and unable to work in cities.

Looking at Oriental Weekly, "Who can assert the warning line of cultivated land in China?" The article points out that the popularity of plastic film and greenhouse has brought revolutionary influence to agriculture in China. Since the 1990s, plastic films and plastic greenhouses have spread rapidly. At present, the coverage area of plastic greenhouses and plastic films in China exceeds 200 million mu. In the severe winter, frozen snow fell, but in the plastic greenhouses in the north and south, green crops showed great vitality.

In the west of China, there are many cold and humid areas, and the time for planting crops every year is very limited. In the long winter, even grass can't survive in the land of northwest, Tibet, Inner Mongolia and many other places. But everything changed after the popularity of greenhouses. Plastic greenhouses allow Qinghai, Tibet and other places with an altitude of about 5,000 meters to grow crops in many places where crops have not been planted before. Not only can crops be planted, but also high and stable yields can be achieved. For example, the yield per mu of cucumber is 4000 Jin, and the yield per mu of pepper is 1800 Jin. Agricultural products can be produced all year round on all the land as long as greenhouses are built. Qinghai, Ningxia, Gansu and other provinces (autonomous regions) rely on plastic greenhouses. Now, this is not a place to import vegetables, but a place to export vegetables, which is an important base for exporting vegetables.

Far eastern economic review said that farmers in China have shaken the world market. In large coastal areas of China, traditional grain growing areas are gradually giving way to orchards and vegetable greenhouses. When the plane looked out from the porthole before landing at Shanghai airport, passengers often mistakenly thought that it was a vast sea under their feet, but it was actually a plastic vegetable greenhouse stretching for miles. Fresh China broccoli is replacing California products and appearing in lunch boxes in Tokyo. In 1980s, the world's largest apple producer was the United States, but now China's apple production is four times that of the United States. China's arable land accounts for only 7% of the world's total, but China's output of melons and vegetables now accounts for half of the world's, which is six times that of India and 12 times that of the United States. 1995 China's output is only 1/3 of the global market.

The so-called war is a battle for information. In the past, the population was small and the population was robbed into slavery. Grab the land in the back. The so-called resource dispute in the future is mainly about energy and water resources. As long as these two resources are not lacking, it shows that science and technology still have great potential. In theory, the sun provides a lot of energy for the earth every day. How can the earth be short of energy? There is more water on the earth than on land. How can there be water shortage? When the energy is solved, other problems will be easy to handle. For example, if the mountains are turned into flat land, the water from Tibet may flow into Xinjiang (considering the geological scruples before the water transfer on the western line, there are many options to choose from if the energy is cheap). After the Tibetan water is transferred to the Tarim desert, it will not flow into the sea quickly, but will only evaporate in Tarim to form water vapor. These water vapor will form rainfall in Tianshan and Kunlun mountains on the edge of Tarim basin, and the rainfall will flow into the basin and evaporate again. In this way, due to the continuous introduction of hidden water, the total water volume will continue to increase until the local total water volume is extremely rich and the water price becomes very low. Northwest China will become an important economic center of China, and Shaanxi, Henan and Shanxi, the traditional treasures of Chinese civilization, will regain their former glory.

Solar energy is almost inexhaustible, but unfortunately it is not storable. Hydrogen is just a carrier, which converts the energy that cannot be stored into the energy that can be stored safely. Now scientists in major countries (including almost all automobile and airplane factories) are studying the use of hydrogen as energy, which will be very cheap and obtained directly from water. The scientific and technological breakthrough of hydrogen is considered as a scientific and technological breakthrough that can eliminate war. This year, an international conference on hydrogen energy was held in Beijing, and the People's Daily also introduced some popular science knowledge (hydrogen energy is the most reliable energy to ensure the long-term development of China/GB/Guandian/1035/2294772.html, and then discuss the credibility of hydrogen energy/GB/Guandian/1036/25/kloc-. Now the United States has the ability to reduce the cost of hydrogen batteries, but automobile manufacturers are all oil-fueled production lines. If the oil price does not rise too much, there is no need to transform the production line into a hydrogen battery. This is also the reason why the Organization of Petroleum Exporting Countries does not dare to raise oil prices excessively. This major breakthrough in hydrogen energy is expected to be realized in the next 30 years (and at any time), when energy will become quite cheap. American scientists predict that with the surplus hydropower in the west, almost inexhaustible hydrogen energy can be extracted from water at a low price. Just as we laughed at the ancient times when we didn't need coal or oil, so later generations laughed at us for begging with golden rice bowls.

One of the reasons for the rapid development of coastal areas is that shipping is relatively cheap, but if energy is very cheap, the importance of expressways will increase, air transportation will become the main means of transportation, and the gap between the mainland and coastal areas will narrow.

The seemingly exhausted resources actually have unlimited potential. If it is a big earth, we will only recycle a little land resources on the fur, and the wider ocean is almost virgin land. According to the predictable technical conditions, there is no problem for the earth to feed tens of billions of people, but the key point is that human beings may never reach 654.38+0 billion people.

Helium 3 is an isotope of helium and can react with deuterium in nuclear fusion. The fusion process has low radioactivity, easy control of reaction process, environmental protection and safety. However, the total reserves of helium 3 on the earth do not exceed several hundred kilograms. There are about 500 million tons of helium 3 on the moon, which can last for thousands of years if it is used as an alternative energy source for human beings. Humans only need to launch two or three spaceships with a load of 10 tons every year, and they can transport a large amount of helium-3 from the moon for all mankind to use as an alternative energy source 1 year, and its transportation cost is only one tenth of the current nuclear power generation. If human beings begin to carry out the plan of extracting helium 3 from the moon now, about 30 to 40 years later, human beings will realize the exploitation of helium 3 from the wild of the moon and transport it back to the ground. However, according to the current development momentum of hydrogen energy, it is not necessary for human beings to mine helium 3 from the moon in the future.

Humans have struggled with wild animals for millions of years, but we have only got rid of the threat of wild animals for decades. Beasts can't photosynthesis, so why should we make room for them? I don't object to the proper protection of wild animals, but first of all, people should be the center. The extinction of wild animals has lost the gene pool available to human beings, but only one child has given the father and mother 23 chromosomes a chance to express themselves, while the other half has lost the opportunity to express themselves, which is no less than the extinction of rare species for human beings' own rich and colorful gene resources.

Even at the current level of science and technology, China can only support 654.38+08 billion people, so don't worry, because China has liberalized family planning, China's population structure, economic structure and fertility desire can barely reduce 654.38+05 billion people, and then it will not reach 654.38+08 billion. Because of corn, potatoes and sweet potatoes, the global population capacity has increased dozens of times. In the past two hundred years, the development of science and technology has only accelerated. Has the technological level reached its limit? With the development of seed, fertilizer, agricultural machinery and other technologies, the population capacity will continue to increase. From a static point of view, there may be a population ceiling in a certain period of time, but the key point is that with the current fertility will and population growth rate, population growth will never reach that bearing capacity limit. Globally, when the population of 1960 was 3 billion, the average living standard was higher than that of 1930 when the population was 2 billion. 1975 When the population is 4 billion, the average living standard is higher than 1960; 1987 When the population is 5 billion, the living standard is higher than 1975. 1999 The world population reached 6 billion, and the average living standard was higher than 1987. From the perspective of China, the living standard of 1980 with a population of1000 million was higher than that of 1970 with a population of 830 million. 1989 When the population reaches 1 1 100 million, the living standard is higher than1980; Now the population is1300 million, and the living standard (including housing conditions) is higher than 1989. Since the quality of life is constantly improving, it shows that scientific and technological progress and economic growth are faster than population growth. Due to the progress of science and technology, the population problem is often "there is no doubt that there is no road, there is another village." Who is qualified to assert the population ceiling of China? Who can assert the population ceiling of China?

"Fear of human beings is usually a false alarm", and fear of overpopulation is "quiet inside", much ado about nothing. Too optimistic will pay a high price, too pessimistic will pay a higher price.