Ecological balance is a dynamic balance. Once disturbed by natural and man-made factors, it exceeds the self-regulation ability of the ecosystem, and cannot be restored to its original stable state, the structure and function of the ecosystem are destroyed, and the input and output of matter and energy are unbalanced, resulting in system component defects (such as the reduction of biodiversity, etc.). ), structural changes (such as sudden increase or decrease of animal population, changes in food chain, etc. ), the energy flow is blocked and the material circulation is interrupted, which is generally called ecological imbalance and serious ecological disaster.

Edit this section of the greenhouse effect-the mystery of the earth's heat.

Greenhouse effect refers to the phenomenon that high greenhouse gases such as carbon dioxide, nitrous oxide, methane and freon are discharged into the atmosphere in large quantities, which makes the global temperature rise. At present, the global annual emission of CO2 into the atmosphere is about 23 billion tons. It has increased by 20% compared with the beginning of the 20th century. Up to now, it is still increasing at the rate of 0.5% per year, which will inevitably lead to global warming, ecosystem destruction and sea level rise. According to statistics, it is estimated that the global sea level will rise by about 20cm by 2030 and 65cm by the end of this century, which seriously threatens low-lying islands and coastal areas.

Edit this paragraph ozone layer destruction-Nu Wa's descendants need to mend the sky.

The ozone layer is a gas layer with high ozone concentration in the upper atmosphere, which can prevent excessive solar ultraviolet rays from irradiating the earth's surface and effectively protect the normal growth of all living things on the ground. The destruction of the ozone layer is mainly achieved through the chain reaction that Freon, a chemical widely used in modern life, enters the stratosphere and decomposes into atomic chlorine under the action of ultraviolet rays. Recent studies have shown that the ozone content in the lower stratosphere 15-20km over Antarctica has decreased by 40%-50%, and the ozone loss may be as high as 95% at some heights. Ozone depletion has also occurred in the stratosphere of the Arctic. The destruction of ozone layer will increase the radiation intensity of ultraviolet β wave. According to statistical analysis, ozone concentration decreased 1%, skin cancer increased by 4%, and the incidence of cataract increased by 0.6%. By the beginning of this century, the ozone layer over the middle of the earth had decreased by 5%- 10%, which increased the number of skin cancer patients by 26%.

Edit this paragraph Land degradation and desertification-hotbed of desert.

Land degradation and desertification refers to the process of land quality degradation and gradual desertification due to the interaction of human factors such as grazing, farming and deforestation and a series of natural factors. 15% of the global land area has been degraded to varying degrees due to human activities. In land degradation, water erosion accounts for 55.7%, wind erosion accounts for 28%, chemical phenomena (salinization, liquefaction and pollution) account for 12. 1%, and physical phenomena (waterlogging and subsidence) account for 4.2%. The average annual rate of soil erosion is about 0.5-2 tons per hectare. The world loses 6.5438+500,000 square hectares of irrigated land every year. 70% of agricultural arid and semi-arid land has been desertified, most seriously in North America, Africa, South America and Asia. In the past 20 years, the number of hungry refugees in the world has increased from 460 million to 550 million due to land degradation and desertification.

Pollution and transfer of waste materials in this section-sequela of industrial civilization

The pollution and transfer of waste refers to the waste gas, waste liquid and solid waste discharged into nature or other countries by industrial production and residents' life, which seriously pollutes the air, rivers, lakes, oceans and land environment and harms human health. At present, there are about 7 1800 chemical products on the market, of which about 35,000 are harmful to human health and ecosystem, and more than 500 are carcinogenic, teratogenic and catastrophic. According to the research, a 1 battery can pollute 60 liters of water, making ten square meters of land lose its use value, and its pollution can last for 20 years. Plastic bags can exist for 450 years in the natural state. Acid rain, the contemporary "death in the air", has been recognized for its influence and erosion on forest soil, lakes and various buildings. The transfer of hazardous waste often becomes a political event of international exchange. The illegal dumping of hazardous wastes by developed countries into the ocean and developing countries has caused great harm to developing countries, directly leading to environmental pollution in receiving areas and the health impact of residents. According to statistics, China's urban garbage has accumulated more than 6 billion tons over the years, occupying 500 million square meters of land, and the annual output of urban garbage per capita has reached 440 kilograms.

Edit this part of the forest area reduction-the earth's lung ulcer

Forest is known as "the lung of the earth" and "the general dispatching room of nature", which has a great regulating effect on the environment. Due to a large number of imports from developed countries and land reclamation, logging and grazing in developing countries, the forest area has been greatly reduced. According to Greenpeace's estimation, 80% of the world's virgin forests have been destroyed since 100. According to the latest report of FAO, the forest coverage rate of the earth is only 26.6% if calculated by the total land area. Forest reduction leads to soil erosion, frequent floods, global warming and species extinction. Humans who blindly claim the earth have pushed the earth to a very dangerous situation.

Edit this paragraph: biodiversity is decreasing-humans will suffer from "autism"

The decrease of biodiversity refers to the continuous disappearance of all biological species, including animals, plants and microorganisms, due to the loss of ecological environment, over-exploitation of resources, environmental pollution and the introduction of exotic species. It is estimated that there are about 30 million species on the earth. 724 species have become extinct since 1600. At present, 3,956 species are endangered, 3,647 endangered and 7,240 rare. Most experts believe that14 of the living things on the earth may face the danger of extinction in the next 20-30 years. In 1990-2020, 5%- 15% of the species in the world may be extinct, that is, there will be 40- 140 species every day. The existence of biodiversity plays an irreplaceable role in the evolution and protection of biosphere life support system.

Depletion of water resources in this paragraph-a crisis faced by human society

Water is the source of life. Water seems to be everywhere. However, the shortage of drinking water threatens the survival of mankind. At present, the global annual water consumption has reached 7 trillion cubic meters. In addition, the discharge of industrial wastewater, the abuse of chemical fertilizers, the random dumping of garbage and the sharp increase of domestic sewage have turned rivers into sewers and lakes into sewage fields. Deforestation caused a lot of water evaporation and loss, and drinking water decreased sharply. Water shortage has sounded the alarm for mankind. According to the water quality monitoring project of Global Environmental Monitoring System, about 10% of the monitored rivers in the world are polluted, and the biochemical oxygen demand (BOD) value exceeds 6.5 mg/L, and the water bodies are polluted by nitrogen and phosphorus. The average phosphorus content of polluted rivers is 2.5 times that of unpolluted rivers. According to United Nations statistics, there are more than 100 countries and regions in the world in urgent need of domestic water, among which 43 countries are seriously short of water, endangering the survival of 2 billion people, mainly in Africa and the Middle East. Many scientists predict that water will become the scarcest resource for human beings in 2 1 century. As people hope, don't let human tears become the last drop of water on the earth.

Edit this nuclear pollution-an unavoidable shadow

Nuclear pollution refers to reflective pollution caused by nuclear leakage or even nuclear explosion due to various reasons. It has a wide range of hazards, extremely serious damage to surrounding organisms, long duration and complex post-treatment risks. For example,1April 1986, a nuclear accident occurred at the Chernobyl nuclear power plant in the former Soviet Union, and130,000 people were evacuated, resulting in economic losses of1500 million dollars.

Edit this paragraph of marine pollution-deadly blue land

The ocean is known as "the frontier of national defense, the channel of trade, the treasure house of resources, the hometown of sex and rain, and the cradle of life". However, she is being seriously polluted. Common marine pollution mainly includes crude oil pollution, floating object pollution, organic pollution and the red tide and Kuroshio caused by it. Marine pollution directly leads to the deterioration of marine environment and the decrease of biological species.

Edit this paragraph of noise pollution-the cry that there will never be peace.

High-intensity noise produced by industrial machinery, construction machinery, automobiles, airplanes, etc. has caused great damage to human living environment and seriously affected human health.

The population explosion has overwhelmed the earth; Environmental pollution makes it scarred; Ecological imbalance made her lose her former glory; Species extinction endangers the whole biosphere. Facing the endless pollution, the river is crying, the spring is moaning and the sea is roaring. Forests disappear, streams sing, grasslands degenerate and dust flies. Our earth is overloaded; Our home is on the verge of decline, and the alarm of human beings is sounded by themselves, so it is urgent to save nature, ecology, environment and the earth. Otherwise, the end of mankind will be a cup of homemade poisoned wine.

Causes of environmental pollution

Generally speaking, environmental pollution can be the result of human activities and natural activities, or the result of the interaction of these two activities. For example, volcanic eruption releases a lot of harmful gases such as dust and sulfur dioxide into the atmosphere, which also pollutes the atmospheric environment. But usually, environmental pollution is more caused by human activities, especially social and economic activities. What we usually refer to is the environmental pollution caused by such human activities. The reason why human activities cause environmental pollution is because

Because there is a fundamental difference between human beings and other creatures: in addition to their own production, human beings also carry out larger-scale mass production, which all other creatures do not have. Because of this, the intensity of human activities is far greater than that of other creatures. For example, in the use of water in the ecosystem, other organisms only use the amount that meets their survival requirements, and humans don't know how many times more water is used than other organisms, so that some local ecosystems are not enough. The emission source of pollutants is called pollution.

Source. The situation of various pollution sources will be described in the fourth section.

Environmental pollution can be classified from different angles. According to the type of environmental pollution system or its leading elements, it can be divided into air pollution, water pollution, soil pollution and so on. According to the social field where pollution sources are located, they can be divided into industrial pollution, agricultural pollution and traffic pollution. According to the form or nature of pollutants, they can be divided into waste gas pollution, waste water pollution, solid waste pollution and noise pollution.

Dyeing, radiation pollution, etc.