Information about the location and extent of damage to the earth.

At present, the top ten environmental problems that threaten human survival are:

global warming

With the increase of population and the continuous expansion of the scale of human production activities, greenhouse gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), chlorofluorocarbons (CFCs), carbon tetrachloride (CCl4) and carbon monoxide (CO) are released into the atmosphere, resulting in changes in atmospheric composition. The air quality is affected and the climate is getting warmer. Due to global warming, it will have various effects on the world. Higher temperatures can melt polar glaciers, and the sea level will rise by 6 cm every 10 year, which will flood some coastal areas. Global warming may also affect the changes of rainfall and atmospheric circulation, making the climate abnormal and prone to droughts and floods, which may lead to changes and destruction of ecosystems. Global climate change will have a series of significant impacts on human life.

(b) depletion and destruction of the ozone layer

In the stratosphere, which is 0/0 ~ 50 kilometers away from the earth's surface, 90% of the ozone gas on the earth is concentrated, and the ozone concentration is the highest at 25 kilometers away from the ground, forming an ozone concentration layer with a thickness of about 3 mm, which is called the ozone layer. It can absorb ultraviolet rays from the sun to protect life on earth from excessive ultraviolet rays, and store energy in the upper atmosphere to adjust the climate. However, the ozone layer is a very fragile atmosphere. If some ozone-destroying gases enter, they will react with ozone and the ozone layer will be destroyed. The destruction of ozone layer will increase the intensity of ultraviolet radiation on the ground and bring great harm to life on earth.

Studies have shown that ultraviolet rays can destroy biological protein and genetic material deoxyribonucleic acid, leading to cell death; Increase the incidence of human skin cancer; Injury to the eyes, leading to cataracts and blindness; Inhibit the growth of soybeans, melons, vegetables and other plants. , and penetrate the water layer at the depth of 10 meter, killing plankton and microorganisms, thus endangering the food chain of aquatic organisms and the source of free oxygen, affecting the ecological balance and the self-purification ability of water bodies.

Reduction in biodiversity

More than 30% species will be extinct within 50 years.

The Convention on Biological Diversity points out that biodiversity "refers to all kinds of organisms from all sources, including terrestrial, marine and other aquatic ecosystems and their ecological complexes; It includes diversity within species, between species and between ecosystems. " In the long process of biological evolution, some new species will be produced, and some species will disappear with the change of ecological environment conditions. Therefore, biodiversity is constantly changing. In the past century, due to the rapid increase of population, unreasonable exploitation of resources by human beings and environmental pollution, all kinds of creatures and their ecosystems on the earth have been greatly impacted and biodiversity has been greatly destroyed.

Some scholars estimate that at least 50,000 species are extinct in the world every year, and an average of 140 species are extinct every day. It is predicted that by the beginning of the 20th century, the global wildlife loss will reach 15% ~ 30% of the total. In China, due to the pressure of population growth and economic development, the unreasonable utilization and destruction of biological resources have also caused great losses to biodiversity. It is estimated that about 5,000 species of plants are on the verge of extinction in recent years, accounting for about 20% of the total number of higher plants in China. About 398 species of vertebrates are also endangered, accounting for 7.7% of the total number of vertebrates in China. Therefore, it is also an important task for us to protect and save biodiversity and the living conditions on which these creatures depend.

(D) the spread of acid rain

Acid rain refers to rain, snow or other forms of precipitation whose PH value is lower than 5.6 in atmospheric precipitation. This is a manifestation of air pollution. The influence of acid rain on human environment is various. Acid rain falling into rivers and lakes will hinder the growth of fish and shrimp in water, leading to the reduction or extinction of fish and shrimp; Acid rain also causes soil acidification, destroys soil nutrition, makes soil barren, damages plant growth, reduces crop yield and damages forest growth. In addition, acid rain will corrode building materials. Relevant data show that in recent ten years, some historical sites in acid rain areas, especially stone carvings, stone carvings or bronze statues, have been destroyed for more than a hundred years, or even more than a thousand years. There are three major acid rain areas in the world. The acid rain area in South China is the only one that has not been treated.

(e) sharp decline in forests.

If the forest disappears, what can we leave?

On today's earth, our green barrier forest is disappearing at an average rate of 4000 square kilometers per year. The reduction of forest destroys its function of water conservation, leading to species reduction, soil erosion and reduction of carbon dioxide absorption, which further intensifies the greenhouse effect.

(vi) Land desertification

Do not let the drought spread again.

The global land area accounts for 60%, of which desert and desertification account for 29%. Every year, 6 million hectares of land become desert. The annual economic loss is $42.3 billion. There are 5 billion hectares of arid and semi-arid land in the world, of which 3.3 billion hectares are threatened by desertification. As a result, 6 million hectares of farmland and 9 million hectares of pastoral areas lose productivity every year. The valleys of Tigris and Euphrates rivers, the cradles of human civilization, have changed from fertile soil to desert. The Yellow River and Yellow River in China have serious soil erosion.

(7) Air pollution

How can such an environment survive?

The main factors of air pollution are suspended particles, carbon monoxide, ozone, carbon dioxide, nitrogen oxides and lead. Air pollution causes 300,000-700,000 people to die prematurely every year due to smog pollution, 25 million children suffer from chronic laryngitis, and 4-7 million rural women and children get sick.

(8) Water pollution

So is water still the source of life?

Water is what we need most in our daily life, and it is also one of the most contacted substances in the world. However, now even water has become a dangerous thing.

(9) Marine pollution

blush

Human activities have increased nitrogen and phosphorus in coastal waters by 50%-200%; Excessive nutrients lead to a large number of coastal algae growth; Red tides occur in the Baltic Sea, the North Sea, the Black Sea and the East Sea of China. Marine pollution leads to frequent red tides, destroying mangroves, coral reefs and seaweeds, resulting in a sharp decline in fish and shrimp in the offshore area and heavy losses in fisheries.

⑽ Transboundary movement of hazardous wastes

Hazardous waste refers to waste with chemical activity or toxic, explosive, corrosive and other harmful characteristics to human living environment, except radioactive waste. The United States stipulates in the Law of Resource Protection and Recovery that the so-called hazardous waste refers to a mixture of solid waste and several solids, which may lead to or lead to an increase in human mortality or serious incurable diseases or disabilities because of its high quantity and concentration. In some countries, capitalists or economic agents of production units arbitrarily discharge all kinds of harmful substances into nature in pursuit of high profits, seriously polluting the environment, especially air and water, causing social harm, causing many diseases and seriously threatening the health and life of the broad masses of people. There are many kinds of water pollution, among which Minamata disease is one of the world-famous public hazards in Japan. Minamata disease first occurred in Minamata Town, Kumamoto Prefecture, Kyushu, Japan in 1953. At that time, it was called Minamata disease because the cause was unknown.

1950, in the fishing village near Minamata Bay, some cats were found to have unsteady gait, cramped and paralyzed, and finally jumped into the water and drowned. Locals call them "suicide cats". 1953, a strange disease was found in Minamata town. At first, he just had slurred speech, unsteady gait, facial dementia, deafness, blindness and numbness. Finally, he lost his nerve, fell asleep for a while, became excited for a while, bent down and screamed and died. At 1956, more than 50 people with the same symptoms were found in this area. Through the investigation of the disease, it was not until 1962 that Minamata disease was determined to be caused by environmental pollution of mercury, especially chronic methylmercury poisoning caused by eating contaminated fish and shellfish. This is caused by methylmercuric chloride discharged from the factory in Minamata town, which pollutes the sea area and poisons fish and shellfish. 1963 after minamata town, a large number of suicide cats and dogs appeared in Niigata prefecture, Japan. 1973, Minamata disease occurred again in Youming Town and other places along the southern coast of Youming Sea. It is reported that the number of these three cases is above 900. In fact, the number of victims in Japan far exceeds this figure, and there are about 1 10,000 victims in Minamata alone.

Mercury, commonly called mercury, is widely used in many industrial sectors. Mercury and its compounds are harmful substances, especially the alkyl compounds of mercury are more toxic. Mercury and its compounds can enter the human body through the respiratory system or digestive system. After inorganic mercury enters human body, the highest mercury concentration is in kidney and liver. The accumulation of organic mercury in human brain is the most significant, followed by liver and kidney. The clinical symptoms after mercury poisoning are very similar to Minamata disease.

In addition to mercury, there are phenols, cyanogens, chromium, arsenic and some heavy metal salts that cause water pollution. These substances are discharged from factories and scientific research units, causing serious water pollution. As a result, harm to human beings has occurred from time to time at home and abroad. Therefore, in the process of developing the national economy and accelerating the four modernizations, we must pay attention to protecting the environment on which human beings depend, preventing pollution, and enabling human beings to survive and develop in a beautiful and comfortable environment.

Black storm: A kind of sandstorm. The dust raised by strong wind forms a sand wall, and the visibility is almost zero.

Since18th century, a large number of immigrants came to the western plains of the United States, which led to three black storms in 1930s. 1A storm in May, 934, which lasted for three days and nights, blew from the west coast to the east coast, forming a gray-yellow dust belt with a length of 2,400 kilometers from east to west, a width of 2,400 kilometers from north to south and a height of 3,400 kilometers. The storm moved eastward at a speed of more than 100 km per hour, sweeping across the North American continent, sandstorms and dark days. In Kazakhstan in Central Asia, a large number of wasteland was reclaimed in 1950s, resulting in a large area of soil. Wind erosion, similar to the dust storm in the 1930s in the United States, has also occurred. In the desert of1160,000 square kilometers in the north of China, 39% is desertification caused by sandstorms caused by human factors.

Sandstorm is a sudden and high-intensity sandstorm disaster. The direct economic loss caused by this in China is as high as 4.5 billion yuan every year. Northwest China, including Xinjiang, Gansu, Qinghai and Ningxia, as well as central and western Shaanxi and Inner Mongolia, are sandstorm-prone areas in China. 1On May 5, 1993, a severe sandstorm caused huge losses in parts of Gansu, Ningxia and Inner Mongolia, with 85 people killed, 264 disabled and 3/kloc-0 missing, resulting in a direct economic loss of 725 million yuan. Seriously affect the economic development of these areas.