（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. Nowadays, 12 million hectares of forest are lost each year worldwide, which means that on average 20 hectares of forest are lost every minute. 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. 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.
The consequences of the sharp decline in forest resources are very serious.
- Oasis will become desert. At present, the global desertification land area has reached 36 million square kilometers, accounting for 1/4 of the total land area, becoming the “biggest killer” of global ecology, and is still expanding at a rate of 50,000 to 70,000 square kilometers each year; the world is affected by desertification in more than 110 countries, and 1 billion people are directly threatened. It means that 1/4 of the earth’s land has basically lost the conditions for human survival, and 1/6 of the population is endangered.
- Soil and water will be lost in large quantities. According to statistics, one-third of the world’s land is severely eroded, and about 60 billion tons of fertile topsoil is lost every year, including more than 25 billion tons of arable soil. The global area of arable land with soil fertility decline and nutrient deficiency has reached 2.99 billion hectares, accounting for 23% of the total land area.
- Drought and water shortage will be more serious. It is measured that each hectare of forest can store about 1,000 cubic meters of precipitation, 10,000 hectares of forest water storage is equivalent to 10 million cubic meters of reservoir capacity. At present, 60% of the continental area of freshwater resources and more than 80 countries lack of water, including water shortage is serious in more than 40 countries, 1.5 billion people are in shortage of drinking water.
- It will cause frequent flooding. A large number of facts show that forests have a strong function of retaining precipitation, regulating runoff and mitigating flooding. With its large crown canopy, deep layer of dry branches and fallen leaves and well-developed root system, forest can play a good role in regulating precipitation.
- It will cause species extinction. There are at least 50 million species on Earth by preliminary count, more than half of which inhabit and thrive in forests. Due to the massive destruction of global forests and the deterioration of the marine environment, the extinction rate of existing species is 1,000 times faster than the natural extinction rate.
- It will aggravate global warming, increase the number of extreme weather events and accelerate the melting of glaciers in the North and South Poles. Forests have a role in absorbing carbon dioxide and releasing oxygen. Each hectare of forest produces an average of 10 tons of dry matter, absorbs 16 tons of carbon dioxide and releases 12 tons of oxygen each year. Since the Amazon rainforest fires and the Australian forest fires in 2019, the number of extreme weather events has increased significantly.
Thus, the role of forests for people and the environment is far greater than their timber value.