Protect the environment, protect the environment and design a blackboard newspaper.

I. Global water resources and water pollution

The total amount of water on the earth is estimated to be about 13.7× 109m3, of which 97.3% is ocean water, which cannot be directly used by human beings. Fresh water accounts for only 2.7%, and most of it exists in ice sheets, glaciers and groundwater at a depth of more than 750 meters in the north and south poles of the earth. The freshwater resources that can be easily utilized are only a small part of rivers, lakes and groundwater, which is less than 1% of freshwater resources. It can be seen that the fresh water resources that can be directly used by human beings and easily obtained are very limited. China's per capita fresh water resources are 2700m3, which is only 28% of the world's per capita fresh water resources.

With the increasing population of the world and the rapid development of industrial and agricultural production, the demand for water is increasing, but the utilization and distribution of water resources are extremely unbalanced, and the available water resources are out of proportion to the population distribution. At the same time, when using water resources, human beings directly discharge untreated wastewater and waste into water bodies, causing man-made water pollution. Therefore, the shortage of water resources has become a serious problem in China.

At present, with the rapid development of industry, agriculture and transportation, a large number of "three wastes" enter water bodies without treatment, and the urbanization process is too fast, which makes rivers and lakes in China generally polluted, among which "Three Rivers" (Liaohe, Haihe and Huaihe) and "Three Lakes" (Taihu, Chaohu and Dianchi) are the most serious. This makes the already serious shortage of water resources in China worse.

Second, the destruction of forests has caused environmental disasters.

Forest is the main body of terrestrial ecosystem, which is directly related to the global ecological environment and human survival and development. In the new historical era, saving forests will still become the main theme of the world.

The death of green

In the early days of human history, there were about 7.6 billion hectares of forests on the earth, and nearly two-thirds of the land was covered with "green clothes". However, since man invented the axe, the forest has been cut down continuously. By the beginning of the 20th century, there were only about 4.89 billion hectares of forests left on the earth. However, human beings have not stopped plundering the forest. By the1980s, according to FAO statistics, nearly half of the world's forest losses, of which 66% were in Central America, followed by 52% in Central Africa and 38% in Southeast Asia.

1990 A report from Helsinki described the consequences of deforestation in some countries as follows: "In Borneo, which Indonesia belongs to, deforestation has caused local workers to leave the forests where they have lived for centuries. Then, the local government put the urban poor on the forgotten land, where thousands of new residents burned the land to farm. As a result, it caused one of the biggest natural disasters in the history of the world: forest fire destroyed more than 22,000 square kilometers of forest. After the fire, Indonesia's climate and ecological environment were affected and agricultural harvest decreased. "

1997, fires are frequent in Indonesia. From July to mid-October, about 19 14000 hectares of forest were burned. According to the Secretary-General of the Ministry of Forestry of Indonesia, about 654.38 million+600,000 hectares of forests in Indonesia are destroyed every year.

This is the case abroad. What about our country?

In the early 1950s, there were more than 9 million mu of subtropical forests in Xishuangbanna, which had been reduced by more than 3 million mu in the 1990s. In the early 1950s, the area of natural forests in Hainan Island was 6.5438+0.8 million mu, while the statistical data of 6.5438+0.984 showed that there were only 3.7 million mu of natural forests in the whole island.

In 1930s, the forest coverage rate in the upper reaches of the Yangtze River reached 30%, but it dropped to 10% in 1960s and 8% in 1990s. The forest coverage rate in Yunnan Province was 50% in 1949, but only 25% in 1980.

The continuous destruction of forests has led to a serious ecological disaster in China. There were three floods in Sichuan Province in the 1950s, five in the 1960s, six in the 1970s, and 10 in the 1980s and 1998 in the Yangtze River valley, which people may remember vividly.

Facing the serious ecological disaster caused by forest destruction, mankind finally realized that protecting forests should be a long-term national survival policy.

According to the statistics of FAO, in 1980, there were artificial forests in the world1380,000 hectares, accounting for 3.6% of the total woodland area and 4.9% of the total forest area. In 1990, the world's artificial forests have exceeded1500,000 hectares. However, although some countries have made efforts in afforestation, it is still very difficult to make up for the global forests that disappear every year. At present, as far as the global ecological situation is concerned, the speed of artificial planting is far behind the speed of natural forest destruction. Therefore, mankind is still facing a serious forest crisis in 2 1 century.

The desert is not far from us.

Desertification is considered as one of the biggest challenges facing mankind in the field of environment. On the first day of 2 1 century, a sandstorm came unexpectedly and swept through the capital Beijing. This reminds us once again that the past debt to the environment is far from over, and the desert is coming to us step by step.

At present, the area of desert, Gobi and desertification in the world accounts for more than 1/5 of the land area, which brings direct economic losses to mankind as high as $26 billion every year.

Since the 20th century, due to over-cultivation, deforestation and land reclamation, the land has become more and more barren. Overgrazing destroys vegetation and intensifies soil erosion. Every continent in the world loses 24 billion tons of topsoil every year. In the past 20 years, the area of topsoil loss in the world is equivalent to the total area of cultivated land in the United States. In addition, 500,000 hectares of land in the world are degraded every year due to improper irrigation. As a global environmental problem, desertification has attracted more and more attention. Facing the global desertification crisis, it was not until September of 1977 that mankind suddenly woke up and sat in the conference hall of Nairobi, Kenya, for the first time to discuss the plan to prevent and control the desert.

From 1950s to 1970s, the desertification land in China expanded at an average annual rate of 1.56 square kilometers. In 1980s, desertification land expanded by 265,438+000 square kilometers every year. By the end of 1990s, the desertified land had expanded at an average annual rate of 2,460 square kilometers, which was equivalent to losing the land area of a medium-sized county in one year.

Protecting the environment and improving the ecology have become the consensus of the international community. 1992 The United Nations Conference on Environment and Development listed combating desertification as a priority area for international action. 1993 10, the negotiating committee for the United Nations Convention to Combat Desertification in Those Countries Experiencing Serious Drought and/or Desert, Particularly in Africa (hereinafter referred to as the United Nations Convention to Combat Desertification) was established in new york.

1994 10 The Ministry of Forestry signed the United Nations Convention to Combat Desertification in Paris on behalf of the government of China.

1997 the first conference of the parties to the United nations convention to combat desertification was held in 10, and a set of international cooperation mechanisms was established, which promoted and promoted the cooperation of the international community in combating desertification.

However, in order to slow down the spread of desertification and improve desertified land, it is estimated that the total cost will be $65.438 billion+$465.438 billion. So far, no government has allocated enough funds to realize this plan. It seems that combating desertification will be the common task of all mankind in 2 1 century.

Green hope

In the past 20 centuries, human beings have created and are creating many unprecedented ecological projects on the earth. After a "black storm" in 1934, President Roosevelt issued an order to build a shelter forest, allocating 75 million dollars to build a shelter forest. From 1935 to 1942, this "grassland shelterbelt project" planted 217 million trees, with a total length of 20,000 kilometers, protecting more than 30,000 farms from storms. Since then, trees have been planted one after another every year. By 1990, the total length of shelter forest has reached 269,000 kilometers, with a total area of 650,000 hectares.

"Stalin's plan to transform nature" began at 1948, which created huge shelterbelts in some grassland areas and forest grassland areas in the former Soviet Union and Europe. From 1949 to 1965, it is planned to build 5.7 million hectares of various types of shelterbelts. According to the survey statistics, from 1949 to 1953, 2.87 million hectares of all kinds of shelterbelts were built, and by 1985, about 5.5 million hectares of shelterbelts had been built in the whole Soviet Union. Therefore, "Stalin's plan to transform nature" is considered as a "major historical event" in the 1950s of the former Soviet Union.

In addition to the above two huge ecological projects, the Green Dam project in Algeria is also an ecological construction project that attracts worldwide attention. In the early 1970s, a large-scale Green Dam project began to be built. Green Dam, also known as green belt, is mainly built in the northeast of Algeria, and it is also a transnational project of Morocco, Algeria, Tunisia, Libya and Egypt. Up to 1986, the Green Dam Project has planted more than 7 billion pine trees with a total area of 350,000 hectares, and the whole project will continue into the 20th century.

Shelterbelt projects in Northeast China, Northwest China and North China are the most ecological projects in the world. The "Three North" shelterbelt system project implemented by 1978 has opened the curtain of forestry ecological engineering construction in China. Subsequently, the state successively launched key forestry projects such as shelterbelt construction in the middle and upper reaches of the Yangtze River. By the end of 1999, 28.269 million hectares, 6133,000 hectares and 3154,000 hectares had been afforested in the Three North Shelterbelt, the Shelterbelt in the Middle and Upper Reaches of the Yangtze River and the Taihang Mountain Greening Project respectively. The construction of coastal shelterbelt system basically closed the coastal backbone forest belt of 6.5438+0.8 million kilometers nationwide; Plain greening project, 850 counties (cities) have basically reached the greening standard, and the national forest network area has reached 3410.9 million hectares; The national sand control project has completed 8 million hectares of sand control and development, and 6.67 million hectares of afforestation and grass planting; The construction of shelter forest system in the middle reaches of the Yellow River, Huaitai, Pearl River and Liaohe River basins has also made gratifying achievements. Ten key ecological projects in forestry, especially the "Three North" shelterbelt project, have significantly improved the ecological environment in some areas of China, slowed down the deterioration trend of the ecological environment in China, and played an important role in promoting the economic and social development of the project area.

Laozi said: man should abide by the law, heaven should abide by the law, and Tao should be natural. At the arrival of the 2 1 century, looking forward to the future, let us live in harmony with nature and make a contribution to the protection of the ecological environment.