Terrestrial Marine Pollution
（Purely personal perceptions, not necessarily correct ！）
It is estimated that up to 95% of food comes from soil, but it takes about 300 years or more for the earth’s surface to form a 1 cm thick soil. Seven spoons of lead will pollute one hectare of land and 200,000 cubic meters of water. In 2012, the global annual output of municipal solid waste was about 1.3 billion tons. In 2018, the global use of synthetic nitrogen fertilizer was as high as 109 million tons. Since plastic was invented, at least 8.3 billion tons have been produced as of 2017. A third of the world’s soils are now moderately or highly degraded, according to the Food and Agriculture Organization. Only in China, 19.4% of its cultivated land area is polluted to varying degrees, and the incidence of cancer is increasing greatly.
About 420 billion m³ of sewage is discharged into rivers, lakes and seas every year in the world, polluting 5.5 trillion m³ of fresh water, which is equivalent to more than 14% of the total global runoff. At present, about 1 billion people in developing countries drink unclean water, and more than 25 million people die from drinking unclean water every year, while averaging 5,000 children die from it every day in the world.