How many people can be fed on Earth? Explain why

Up to 200 billion The Earth is too small

The Earth can feed 800 billion people.

The rapid growth of the world's population is accompanied by the rapid development of the global social economy. Two thousand years ago, the population of the planet was less than 100 million, but by 1650 the total population had doubled. After another 200 years, the population doubled again, and by 1830 it had exceeded 1 billion people.

Since then, the interval between the doubling of the population has become shorter and shorter, from 1 billion to 2 billion, in only 100 years, and from 2 billion to 4 billion, it has taken only 45 years. Since the beginning of the 20th century, the world's population has shown a first-class growth: the global population has reached 6 billion in June 1999, about four times the global population in 1900 and twice the global population in 1960.

The limits of our population

According to the estimation of the National Conditions Analysis Research Group of the Chinese Academy of Sciences, China's population carrying capacity should be controlled at a maximum of about 1.6 billion, and the most suitable population should be about 700 million. That is to say, 1.6 billion or 1.7 billion is a lifeline for the Chinese population.

According to the carrying capacity of the ecosystem, scientists propose that the ideal carrying capacity of China's ecology should be 700 million to 1 billion people.

It is mainly based on the following five points: according to the grain production, it should not exceed 100 million people; According to the ideal load of energy, it should not exceed 100 million people; According to land resources, it should not exceed 1 billion people; According to fresh water**, it should not exceed 100 million people; According to animal protein**, it should not exceed 100 million people.

Opinions differ on the carrying capacity of the Earth's population. There are roughly three main points of view:

1. Pessimists believe that the earth is already overpopulated.

2. Optimists believe that with the progress of science and technology and the continuous development of new resources, the carrying capacity of the earth should be unlimited.

3. The centrists believe that the limit of the earth's carrying capacity is 10 billion people!

The earth's resources can live for 10 billion people for 100 years, and for 8 billion people to live for 300 years. If the growth rate of new resources is certain.

Resources are divided into renewable and non-renewable two, the total amount of non-renewable resources (such as coal, oil) is certain, set to x, renewable resources (such as pin bridge hydro energy, wind energy) in essence ** in the sun's loss of sensitive and violent irradiation, so the annual increase in the amount of dust to a certain amount, set to y, according to the title:

100*100=x+100*y

80*300=x+300*y

Solution: x=3000, y=70

If the annual consumption is equal to the new increment, then x will never decrease, and the resources will be available for use forever, so that there will be enough to feed 7 billion people.