（Purely personal perceptions, not necessarily correct ！）
Data from 2020 shows that the total global forest area is now 4.06 billion hectares, accounting for nearly 31% of the total land areas. Since 1990, a total of 420 million hectares have been destroyed, but thanks to significant reductions in deforestation, large-scale afforestation and natural growth of forested land in some countries, the net loss amounts to 178 million hectares. The situation is even more critical for tropical rainforests, which are an important part of forest resources. The tropical rainforest is the world’s largest biological gene pool and is habitat to more than half of the world’s plant and animal species. It is also a huge reservoir for carbon biocycling and storage activities, with the Amazon rainforest alone producing 1/3 of the world’s oxygen. Since the tropical rainforests are located mainly between the North and South Tropic of Cancer, of which are mostly developing countries. Due to their poverty and rapid population growth, an important part of the planet is destroying by deforestation. The top three countries in the world with tropical rainforests, Brazil, the Democratic Republic of Congo (DRC) and Indonesia, are all at historical lows in terms of forest cover.
Once the tropical rainforest is destroyed, it is impossible for humans to restore it. Because the soil of tropical rainforests is very poor, vegetation mainly depends on the dry branches and fallen leaves. There are many trees that are hundreds or thousands of years old. If the trees are cut down in large numbers, it will not be able to produce dry branches and fallen leaves, coupled with frequent rain, nutrients can not be stored, the remaining vegetation will slowly die. Therefore, the tropical rainforest is like the mineral resource, once destroyed, it disappears.
According to studies, more than 20% of the world’s tropical rainforests have been completely lost in the last 100 years, and another 10% are suffering from heat, drought and fire.