（Purely personal perceptions, not necessarily correct ！）

Surfaces of the earth covers an area of 510 million square kilometers, but lands only occupy 149 million square kilometers, which accounts for 29.2% of the total earth surface areas.  However, these lands also include the Arctic and Antarctic, deserts, dense forests and polluted areas that are not suitable for human habitation. As global warming becomes more and more serious, glaciers will melt and land areas will further shrink. Studies have shown that each time sea level rises for 50 meters, land areas in the world reduce by 60%. If the Arctic ice cap disintegrated, global sea level will rise for nearly seven meters. If all Arctic and Antarctic ice caps melts, sea levels will rise by nearly 70 meters. All these are happening now and the trend has already been formed. And it will increase exponentially. If so, there will be no way to control it.

Carbon dioxide is a big cause of global warming. Carbon dioxide emitted by human beings reached in 2012 reached 39.1 billion tons. In 1850, which is at the end of the first Industrial Revolution, the discharge amount of carbon dioxide was 198 million tons, which has an increases of nearly 200 times.

It is easy to discharge carbon dioxide, but it is hard to get rid of it. We can only rely on the self-repair system of the earth. It is time for human beings to wake up when so many abnormal climates and more and more extreme weather appeared.

In fact, global warming is only one factor leading to the decline of land resources. In additional to global warming, desertification, soil erosion and land pollution are also leading factors.

According to statistics, land desertification occur inlands of 60,000 square kilometersin the world every year. As many as 5 to 7 square kilometers of lands are lost due to desertification every year and almost 11 hectares of lands are lost each minute.

Because of the serious destruction of forests, soil erosion becomes increasingly serious. According to data of 2010, one-third of the world’s lands is severely eroded and more than 60 billion tons of fertile topsoil are lost every year, including more than 25 billion tons of arable soil. 2.99 billion hectares of cropland all over the world are suffering from soil degradation and nutrient deficiency, which accounts for 23 percent of the total land areas.

Lands are also seriously polluted because where there are people, there are different degrees of pollution. Soil pollution statistics released in 2021 showed that 19.4% of China’s cultivated lands were polluted to different degrees. That is to say, about 370 million mu cultivated lands needed soil improvement and treatment. This can be revealed in the current high incidence of cancers.