In spring, there are more sandstorms in the north, which are caused by the destruction of vegetation and desertification. The largest desert in the world is the Sahara desert, which is located in Africa, accounting for 30% of Africa’s land area. From this we can see the scale of this desert. The desert is a place of death. Where can you cross the earth? But no one can cross the Sahara desert. As long as you dare to go deep, it’s hard to think of it. In history, there are many adventurers who go to Taobao in the desert, less than one percent of them can come back, which shows the ruthlessness of the desert.
Someone may ask: How did such a huge desert come into being? Is it natural? Of course not. As early as 8000 years ago, the Sahara desert was an oasis, with flowers and trees, clear water and countless birds flying in the forest and grassland. It was a beautiful scenery.
At this time, people gradually began to live on this land. They saw the rich forest resources here, began to cut down a large number of trees to build houses, raised a large number of cattle and sheep, and ate the grass here without any plan. In this way, we just cut down trees, cattle and sheep eat grass, regardless of planting. Under the vicious circle, the forest has been cut down and the grass has been eaten up. Without the green vegetation, a large amount of loess has been blown away by the strong wind, and the sand has been left. After about 1000 years, it has completely become a big desert.
In fact, the formation of deserts is caused by man-made destruction of the environment. Human beings do not know how to make rational use of the resources formed by the earth after countless years. Driven by interests and greed, they frantically ask for the resources from nature. Sooner or later, it will be used up. Once the earth’s resources are used up, it will face despair.
Why is the rapid development of space technology? The reason is that scientists have foreseen the future of the earth. Hawking once said that the time left for human is less than 100 years. Within 100 years, human beings must emigrate to other planets to survive. Hawking said that it is obvious that the consumption rate of the earth’s resources is amazing, and the global population is increasing year by year.
With the progress of space science and technology, only when human beings enter the interstellar civilization can they have the ability to develop the resources of other planets, so that human beings will not be trapped after the earth’s resources are exhausted in the future. Only by exploiting outer space resources and going out of the earth can human beings develop in a longer term. But there is not much time left for human beings. Now we are racing against time to find a planet suitable for human survival before the earth’s resources are exhausted and the environment is destroyed, or to transform a planet, and then immigrate.
Now scientists are focusing on Mars, because Mars is close to us and relatively easy to transform. Mars may be the second home of human beings in the future.