(1) The atmospheric environment is deteriorating. The main manifestations are: increase and intensification of climate disasters, global warming, melting of glaciers, corresponding rise in sea level, coastal lowlands are threatened by seawater inundation; atmospheric composition changes that are not conducive to humans, carbon dioxide increases, and the concentration of the ozone layer that alleviates ultraviolet radiation The hole in the ozone layer above the earth's two poles is getting bigger and bigger, and a variety of ingredients harmful to humans are also increasing. According to a 1997 report by the Ridge National Laboratory in the United States, the concentration of carbon dioxide in the atmosphere has increased by 30% since the industrial revolution, methane has doubled, and nitrogen oxides have increased by 15%. Carbon dioxide, methane, and nitrogen oxides are all gases that can produce a greenhouse effect, and an increase in their concentration causes temperatures to rise.

These changes in the atmosphere have natural causes. Volcanic eruptions and forest fires can send pollutants into the atmosphere. However, human use of fossil fuels such as coal and oil releases carbon dioxide, methane, nitrogen oxides, sulfur dioxide and other harmful gases and dust, which pollutes the atmosphere more seriously. Burning coal produces the most pollutants. The resulting poisonous fog and acid rain are outstanding manifestations of air pollution. The "murderous smog" first appeared in Belgium in 1930, and enveloped London four times from 1948 to 1962. The concentration of sulfur dioxide and dust in the smog far exceeded what people could bear, causing a total of more than 6,000 deaths. Although such records are rare, polluted air generally fills the spaces of many industrial and mining areas and cities.

Ordinary rainwater often contains trace amounts of carbonic acid. The polluted atmosphere has increased components such as sulfur dioxide and nitrogen oxides, making the rainwater more acidic. Now people define rainwater with a pH value below 5.6 as Acid rain. It looks like ordinary rainwater, but the acidic substances contained in it enter the soil and water on the land surface. The organisms that rely on these water and soil for survival are adversely affected, especially the destruction of forests. The pH first recorded as acid rain was 5.9 in 1939 (the pH of pure water is 7). By the 1950s, the pH value of acid rain had dropped to 3-5, with a record low of 2.1, which is about as acidic as vinegar or even more acidic. It shows that with the development of industry, the air is becoming more and more polluted. Since the atmosphere containing pollutants is flowing, it can travel across the ocean. The acidic components emitted by Japan can travel to the United States and form acid rain. It is not surprising that the acid rain in Canada originates from the United States. Scientists have determined that two-thirds of the sulfur dioxide gas gathering over Sweden and Norway comes from industrial areas in the United Kingdom and Germany.

The rapid development of my country's economy has also caused the area covered by acid rain to expand rapidly. By 1999, it had become the third largest acid rain area in the world after Europe and North America. my country still uses coal as the main fuel. A cause of serious air pollution.

The damage caused by air pollution is extremely widespread. In many cases, it does not appear in the form of poisonous fog, acid rain, etc., but all kinds of organisms are often affected by it, and the damage to forests and crops is particularly significant. Frequent breathing of polluted air is also a threat to human health, especially respiratory diseases, which increase. Living in a severely polluted air environment for a long time is like chronic poisoning.

The ozone in the atmosphere cannot make ends meet and its concentration is decreasing. Scientists first discovered in 1985: In September and October 1984, the concentration of ozone in the ozone layer over Antarctica dropped by 40% compared with the mid-1970s. It could no longer fully block excessive ultraviolet rays, creating this special circle that protects life. The emergence of "holes" threatens the survival of phytoplankton in the Antarctic ocean. According to a report by the World Meteorological Organization: In 1994, it was found that the ozone content in the stratosphere over the Arctic region also decreased, and in some months was 25-30% lower than in the 1960s. The hole in the ozone layer over Antarctica is still expanding. In September 1998, it set a historical record with an area of ??25 million km2. *

Why does the ozone layer have a "hole"? Many scientists believe that it is the result of the use of Freon as a refrigerant and other uses. Freon is composed of carbon, chlorine, and fluorine. After the chlorine ions are released into the atmosphere, they can repeatedly destroy ozone molecules and remain in their original state. Therefore, even though the amount is very small, it can reduce ozone molecules to the point of forming a "hole." Chinese scientists recently proposed that the role of Freon alone is not enough. The flow of particles from the solar wind is concentrated toward the geomagnetic poles under the action of the geomagnetic field and destroys the ozone molecules there. This is the main reason. (Yang Xuexiang, 1999) In any case, artificially sending chlorine ions into the atmosphere is ultimately a harmful behavior.

In the atmosphere, matter is loosely distributed and moves rapidly. The slightest external interference may break the original balance. Therefore, the impact of human activities on the atmospheric environment cannot be underestimated.

There are about 100 kinds of pollutants in the atmosphere that have caused harm or been noticed by people. Among them, the ones that have a wide range of impacts and pose a greater threat to the human environment mainly include hydrocarbons, carbon monoxide, nitrogen oxides, Sulfur oxides, hydrogen sulfide, fluoride, photochemical oxidants and particulate matter, etc.

(2) The hydrosphere is seriously polluted

The biggest problem in the hydrosphere is the shortage of fresh water resources and uneven geographical distribution, which has become an obstacle to the sustainable development of some countries and regions (see Chapter Chapter 12), and the pollution of the hydrosphere has threatened the survival of mankind.