Mars immigrants and Saharan immigrants

As we all know, observing the position of the earth from space, we can see a beautiful blue planet, which is what the earth looks like in space. This is because 7 1% of the earth's surface area is occupied by the ocean, and less than 30% is for human habitation. However, not all areas on land are suitable for human survival. According to the statistics of scientists, nearly 17% of the land is closed to humans due to climate and topography, and this area is still increasing rapidly. 、

In the uninhabitable area of 17%, 10.3% is occupied by desert. We all know that the desert climate is dry and lacks water resources, so these places are not suitable for human survival. In recent decades, with human activities, a large number of greenhouse gases have been produced, the temperature of the earth has increased year by year, and the climate has become worse and worse. Many areas on the earth that were prone to drought are developing towards desertification, and even many areas are swallowed up by desert.

In addition, due to the unreasonable use of land by human beings, the fertility of many lands is rapidly losing, and the desertification of the earth's land is becoming more and more serious. Desertification of land will also make the climate in this area very bad. In this case, mankind had to leave the original land and began to migrate to other areas. But the erosion of wind and sand will also lead to the rapid spread of desertification areas, so in fact, the land suitable for human habitation has been shrinking in recent decades.

Although human beings are now controlling the spread of desertification by planting trees and returning farmland to forests, this method is actually very slow compared with the erosion speed of sandstorms. And we also know that many countries are keen to explore outer space now, and are even preparing for human beings to explore alien territories. But it takes at least 1 century to establish a base on the moon or immigrate to Mars.