Tip: When did the Indian population surpass China?
At present, the population of India is139.6 billion. In the census from 200 1 to 20 1, the population of India increased by 17.7%, that is, 1.865438+ in1.
The earth on which human beings live: How many people can it carry?
From 50,000 years ago to 6,543.8+0,000 years ago, the global population was only a few million, but by 654.38+0.800, the global population had reached 65.438+0 billion, and by 654.38+0.920, the population had exceeded 2 billion!
However, from 1920s to now, the global population is close to 7.9 billion, and it will soon exceed 8 billion. From the curve, just like a spaceship approaching the speed of light, the curve of mass increase effect suddenly rises, and a little time change will produce great changes. According to the prediction of United Nations population experts, the population of the earth will exceed 654.38+000 billion by 2050!
The earth with a diameter of 1.27 million kilometers and a surface area of more than 5 1 10,000 square kilometers is definitely an astronomical figure for small human beings, but modern human aircraft can circle the earth once in a day. If it is a satellite in low earth orbit, it can circle in an hour and a half.
Human beings need to consume resources to survive on the earth, and the output of the earth is limited, because human beings always need to consume energy from birth to death, which comes from biomass energy generated by the earth, that is, solar energy stored in the earth's ecosystem. So how many people can the total * * * feed on the earth?
In 20 12, the United Nations Commission on Population and Development released the largest sustainable population list on the earth, with the most typical estimate of 8 billion, while the smallest scale was 2 billion and the largest scale was 1024 billion, which was quite different. What caused this order of magnitude difference?
The per capita resource consumption rate is the key.
According to Science.com 22017, the food consumption level of an ordinary American middle class is 3.3 times of the living standard and 250 times of the living standard of clean water. If all human beings in the world live like the ordinary middle class in the United States, the carrying capacity of the earth will not exceed 2 billion!
American garbage is world-famous. Jerry Guo is a famous UP owner. He once talked about the garbage problem in America. He found a few trash cans at random in the supermarket, and the whole bucket of bread, dessert and roast chicken was dumped, which was really heartbreaking. These are all foods produced by grain production and complicated processes, and the reason for dumping them is that they are not fresh.
The waste of energy is even more shocking. For example, a statistic in 20 19 shows that the average annual electricity consumption of Americans is 12000 kwh, with 5,000 liters of gasoline, which is more than twice that of the British (5,000 kwh), 2.5 times that of China and 3 times that of the world! You can imagine what a scourge Americans are on earth.
In recent years, all kinds of waste in the United States have increased. (Growth of all kinds of solid waste)
Of course, if the poor areas in Africa only have enough food every day, considering the future progress of agricultural technology and the comprehensive and effective utilization of the earth's soil fertility, then the limit of the earth's carrying capacity is 1024 billion, but this figure seems to be of little significance. After all, no one wants to live like a canned sardine.
It is difficult to comprehensively evaluate the population carrying capacity. For example, we are now facing a very headache, that is, educational resources. High-end high-quality educational resources are limited, and everyone is striving for these high-quality resources. However, people in underdeveloped areas are scrambling to fill their stomachs every day.
According to the prediction of David Satterthwaite, a senior researcher at the Institute for International Environment and Development in London, it is predicted that most of the growth in the next two decades will occur in the urban centers of current low-income and middle-income countries, such as the rapidly expanding Mexico City, Tehran, Mumbai and New Delhi, India, and some low-income countries in Africa.
Mumbai Slum-Dharavi
These cities are facing huge problems. For example, Mexico City, which is located in the sediments of ancient lakes in the plateau basin, has an annual subsidence rate of more than 0.5 meters because of groundwater pumping by residents, and the subsidence in Tehran, Iran is also due to excessive use of groundwater.
Mexico City
Another problem is pollution discharge. Although India ranked third in emissions in 20 19, accounting for 6% of the global pollution emissions, their emissions are "high quality", because a large amount of soot is discharged into the atmosphere without desulfurization, which is much more serious than simply discharging carbon dioxide.
Sulfur dioxide pollution in India
The problem under global warming: it is no longer life, but survival!
There are several landmark events in the rapid population expansion. One is the industrial revolution. From small-scale production to industrialization, various means of production began to enter the era of large-scale industrial production. This process is revolutionary in promoting the global economy.
The other is the progress of medical technology. From the end of the eighteenth century to the end of the twentieth century, the death rate at birth dropped by more than one order of magnitude, and the average life expectancy of the population increased by more than thirty years, which are the key supports for population growth.
The other is the progress of agricultural technology, such as the use of chemical fertilizers and the development of intensive agriculture. Population expansion and food and clothing are the key points. Without the support of food, even the best technology can't feed a huge population.
But another fact is before mankind. Since the industrial revolution, the global temperature has risen to1.65,438+05℃. If emissions are not controlled, the temperature will rise by more than 2.5℃-3℃ by 2 100, which will make the earth's ecology invincible, the polar ice sheet will melt, the sea level will rise, and the greenhouse effect will be unstoppable.
So what species will replace humans this time? Of course, scientists have also proposed new solutions. For example, let's stop screwing around on earth. There are so many resources on asteroids. Why don't we go there to find them and colonize the planets in space and the solar system?
Further reading: How many people have been on the earth?
1On October 23rd, an interesting article was published on the PRB website. According to the human traces discovered by archaeologists in various periods and the estimation of technological progress, the total population that has appeared in the history of the earth is counted. The data is/kloc-0.08 billion, and the current population of the earth is close to 7.9 billion, which means that there are already about/kloc-0.00 billion people on the earth.
This extends to a very interesting question. It is said that human souls will be reincarnated, so where do these extra souls come from?