1, change species (intentionally or unintentionally causing species to disappear or introduce species)
For example, in 1859, a farmer brought 25 rabbits from England to Australia, which caused serious damage to the Australian ecosystem because there were no natural enemies.
For another example, 1906, Kaba forest in Arizona, USA, killed carnivores to protect deer, which led to a large number of deer breeding, and finally there was no food and it was on the verge of extinction.
2, the change of environmental factors (a large number of pollutants into the environment)
3. The destruction of the information exchange system (destroying pheromones released by organisms to drive away natural enemies, repel different species, attract the opposite sex, etc.). ).
Second, there are natural factors and human factors that destroy the ecological balance. Natural factors such as floods, droughts, earthquakes, typhoons, landslides and tsunamis. The destruction of ecological balance caused by natural factors is called the first environmental problem. The destruction of ecological balance caused by human factors is called the second environmental problem. Human factors are the main cause of ecological imbalance. Human factors mainly include the following three aspects: (1) changing environmental factors. For example, human production and life activities produce a lot of waste gas, waste water, garbage and so on. , continuously discharged into the environment; Unreasonable or predatory use of natural resources by human beings, such as blind land reclamation, deforestation, excessive reclamation of water surface, overloading of grassland, etc., will worsen environmental quality, have short-term or long-term effects, and make the ecological balance unbalanced. (2) changing biological species. In the ecosystem, blindly adding a species may destroy the ecological balance. For example, the Welland Canal, which was dug by the United States in 1929, connected the internal drainage with the ocean, causing octopus to enter the internal drainage, reducing the annual output of trout from 20 million kilograms to 5,000 kilograms, seriously damaging the inland aquatic resources. Reducing one species in the ecosystem may also destroy the ecological balance. In 1950s, China killed a large number of sparrows, which caused serious pests in some areas. The reason is that sparrows, the natural enemies of pests, have been killed, and pests have lost their natural inhibitors. (3) Damage to the biological information system. Only through mutual information contact can organisms maintain their own clusters and reproduce normally. Man-made release of a substance into the environment interferes with or destroys the information connection between organisms, which may lead to imbalance or destruction of ecological balance. For example, many insects in nature induce male adults of the same species to mate by secreting and releasing sex pheromones. If the pollutants discharged into the atmosphere can react with them, the sex pheromones of female insects will lose their physiological activity of attracting male insects, which will inevitably affect the mating and reproduction of insects and eventually lead to the decline or even disappearance of the population.
Third, paying attention to protecting the environment while pursuing its own development can be said to be a great progress of mankind.
In ancient times, the relationship between man and nature was unequal. Human beings are weak, limited by nature everywhere, but unable to change nature. Therefore, it has become a rare quality for human beings to regard nature as an enemy and the world as an enemy. The spirit of fools has been praised for thousands of years.
With the advent of the industrial age and the continuous improvement of human science and technology, the relationship between man and nature has been reversed, and man has become a strong man, while "gentle nature" has become an easily injured object. High-purity chemicals, such as pesticides, paints and detergents, pose a great threat to the natural environment; Large-scale energy consumption has changed the composition of the atmosphere, thus changing the climate of the earth; With the improvement of sanitary conditions and the sharp increase of population, human activities have destroyed a large number of forests and wetland resources on the earth. As a result, "gentle nature" has become "ferocious nature", and everything imposed on it by human beings will eventually be returned to human beings. In areas where water and soil are polluted by high-purity chemicals, the incidence of deformed children and terminal diseases is much higher than that of normal people; Once the oil resources are exhausted, the quality of human life and the normal operation of society will inevitably encounter problems; Abnormal climate will inevitably bring floods or droughts, and famine will also be accompanied by various natural disasters. "Cruel nature" will make human beings weak again, and the relationship between human beings and nature will return to the starting point.
In order to change this situation, human beings must protect "gentle nature" and prevent it from deteriorating. Protecting the environment is to protect human beings themselves, which is valuable knowledge after industrialization and extreme expansion of self-confidence.
Countries all over the world are also aware of this problem. 10 years ago, 178 leaders gathered in the Brazilian city of Rio de Janeiro to discuss environmental protection. The leaders plan to protect the earth's environment, reduce greenhouse gas emissions and promote the welfare and development of mankind. 1997, 160 countries signed the Kyoto protocol aimed at reducing carbon dioxide emissions in Kyoto, Japan. However, the United States, the largest emitter of carbon dioxide, refused to implement it because emission reduction hindered economic development. Last year, at the Earth Summit held in Johannesburg, South Africa, world leaders and scientists continued to discuss plans to improve the environment.
10 years have passed, although mankind has made some progress in protecting the environment, the differences are still serious. What is the state of the earth now? What attitude should we take to meet the future?
7 gratifying progress
Awareness of environmental protection is increasing.
After long-term publicity, environmental awareness has been accepted by many people and governments, and people have begun to care about the impact of human activities on nature, hoping that this impact will not worsen the natural environment. Governments began to deal with environmental problems through cooperation. The Rio de Janeiro Summit on 1992, the Kyoto Climate Conference on 1997, and the Johannesburg Summit last year all reflected the strengthening of the world's environmental awareness. Although the United States refuses to implement the Kyoto Protocol for its own benefit, which has caused great damage to future transnational environmental cooperation, the progress of international environmental protection efforts is an irreversible trend.
The clean car came out.
Hybrid electric vehicles have come out and run on the roads of Japan, Western Europe and the United States, which can greatly reduce carbon dioxide emissions. The inventor of the "Super Car" company in Colorado, USA, is developing a zero-emission car. One of the cars is designed to use hydrogen as fuel. The inventor claims that it is unnecessary to bring drinking water when driving this car for a holiday, because it emits 100% pure water. The prospect of electric vehicles is also very promising, and it is likely to become the next generation of personal mobility tools.
Ban 12 "environmental killer"
At the United Nations General Assembly held in Stockholm, Sweden in 20001year, it was decided to restrict the use of 12 chemicals containing carbon and chlorine preparations worldwide. This move is to protect air, water and soil resources from pollution. The meeting called for limiting or completely eliminating persistent organic pollutants such as chlorine, DDT pesticides and PCBs pesticides. 1987, the agreement prohibiting the use of chlorofluorocarbons has played a role, and the destruction of the earth's ozone layer has slowed down.
Develop eco-tourism
The International Ecotourism Association, headquartered in the United States, describes ecotourism as "responsible tourism that protects the environment and supports the welfare of local people". Eco-tourism and its profits have become an important channel to support the financial revenue sources of developing countries around the world, and it is growing rapidly at an annual rate of 30%. The natural environment, like cultural traditions, has become an important driving force to attract tourists. But environmentalists are still worried that the market economy function of ecotourism is far greater than the significance of protecting the environment.
Corporate environmental protection movement
Large companies are increasingly aware that environmental protection can help them attract more customers. Xerox's "Waste-Free Plan" recycled 80% of the harmless solid waste produced by its factory in 2002. It also took out more than 60,000 tons of buried electronic waste and recycled it. This move by Xerox can save millions of dollars every year. Xerox's sustainable development method has been welcomed by environmental groups. Many large companies are also aware of the great role of environmental recycling. Shell, IBM and other world-renowned companies have launched their own "clean plan".
More environmentally friendly buildings
The most important standard of environmental protection building is to reduce energy consumption. Some houses in Europe began to install tiles to absorb solar energy, while "Trench" company in California began to install high-performance insulating glass on the roof of the office. The environmental protection design of the chesapeake bay Foundation headquarters office building in Annapolis, Maryland, USA is even better. The toilets in the office building are flushed with collected rainwater through a special water storage device. Use solar panels to power the office. Compared with ordinary buildings of the same area, this office building consumes only one-third of electricity and one-tenth of pure water.
Reduce the harm of acid rain
The United States and Europe have proved that the reduction of sulfur dioxide and nitrogen dioxide emissions has greatly improved the earth's surface environment. In 1980s, developed countries began to control the emission of sulfur dioxide to reduce the great harm of acid rain to the environment. They began to ban factories from using carbon as fuel, and instead used cleaner energy sources such as natural gas and purified carbon to generate electricity. Cars have also been modified, using higher gasoline grades, and the emission of nitrogen dioxide after combustion is greatly reduced. The harm of acid rain in the United States and western Europe has been greatly reduced. Take Britain as an example. In the past 15 years, the harm of acid rain has been reduced by half.
Seven worrying signs
Earth warming
Scientists have warned that increasing greenhouse gas emissions will make the climate change sharply and the sea level rise. According to the statistical report of the National Meteorological Administration, the average temperature in the three months from 20011to 2002 1 was the highest since 1895. Similarly, the global average temperature in these three months is also the highest since 1895. The direct threat of rising temperature is rising sea level, which will also lead to other extreme weather phenomena and natural disasters.
Unrestricted demand for oil.
There are many rivers on the earth, but there is one river that we don't realize, and that is the river formed by oil. Every day, the river formed by oil surrounds us, and the flow rate of this river is 1 100 cubic meter per second. Since 1990s, the world oil consumption has increased by 14% and is still increasing. Of the 24 billion tons of carbon dioxide released into the atmosphere every year, 40% comes from the combustion of oil. In human history, the content of greenhouse gases in the atmosphere is the highest in 420 thousand years. Two-thirds of the world's oil reserves are concentrated in the Middle East, which has also become the most important factor of political and economic instability in this region. Sometimes, people will think that God loves the Middle East too much and has given it such a concentrated and rich liquid gold, but although oil is good, it has also brought endless conflicts and disputes to the region. Before the fuel consumption is exhausted, such conflicts and disputes seem endless.
Disappearing wetlands
Many people actually don't know the importance of wetlands. Wetlands provide habitats for fish, many birds and amphibians, and become an important part of the ecosystem. In addition, wetlands have a strong ability to digest pollutants. However, worldwide, the area of wetlands is shrinking rapidly. Wetlands are doomed from the Amazon basin to Iraq. The root of the disappearance of wetlands is human agricultural activities, water conservancy activities and other development activities. Reclaim more arable land, build more dams and make wetlands disappear gradually. Scientists estimate that the area of wetlands has decreased by 50% in the past century. 3 1 years ago, 132 countries signed the Wetland Protection Treaty in Iran. But in fact, the binding force and function of the treaty are quite limited.
Super dams are increasing.
People think that building super dams shows their ability to transform nature. It is true that dams transform nature and provide electricity, but they also bring many adverse effects to the environment. The dam changed the natural flow direction of the river and the direction of natural flood discharge. Dams form unnatural reservoirs on the ground, which affects the natural distribution of fish. 1950, there were about 5,000 dams in the world, but by 2000, the number of super dams had soared to 45,000, and the scale was getting bigger and bigger, playing an increasingly important role in transforming nature. On average, two dams with a height exceeding15m are built every day, and most of the new dams are located in developing countries. Some dams are180m high and1500m wide. The cost of building such a dam is staggering. In order to flood a large area of land, countless species have to choose another habitat.
Fewer and fewer coral reefs
Of all marine life, a quarter of the habitats are coral reefs. But in the past 50 years, the number of coral reefs has decreased by 27%. Only in 1998, the number of coral reefs in the world suddenly decreased by 16%. The most direct cause of coral reef death is the warming of the sea. Of course, the increase of solar radiation in the ocean and the savage fishing methods of fishermen are also important reasons for the disappearance of coral reefs.
Overfishing
Human science and technology have made the speed and quantity of fishing exceed the natural replenishment capacity of the ocean. As a result, the number of many fish has dropped sharply, and even endangered. At present, the total amount of fish in the ocean is decreasing at the rate of 1% per year. Scientists propose to designate specific sea areas as protected areas, stop fishing and give nature time and opportunity to save again. But humans seem unwilling to give nature such an opportunity. Restricting fishing will directly affect fishermen's income and quality of life. The fish market only pays attention to price and profit, and never considers species protection.
Disposal of nuclear waste
In 2003, more than 440 commercial nuclear reactors in the world will produce 1 1000 tons of nuclear waste. How to deal with these nuclear wastes poses a difficult problem to mankind. First of all, these nuclear wastes are likely to leak. Secondly, these nuclear wastes are likely to be obtained by terrorists and used for terrible purposes. There are more than 100 nuclear reactors in the United States, which produce about 25% of the world's total nuclear waste, while there are more nuclear waste dumps, including 1, 3 1. * * * More than 1 100 million people live near the nuclear dump 100 km. No matter where nuclear waste is transported, it will inevitably cause pollution to the local area. The more nuclear energy is used, the more similar pollution will occur. While enjoying the super power of nuclear energy, human beings must never forget the hidden worry of nuclear waste.
Seven shocked voices
"At present, people's awareness of protecting the earth's resources is unprecedented, but the large-scale and extensive destruction of wildlife habitats has not slowed down. I am encouraged by the scientific and technological achievements of mankind, but the destruction of species diversity by these scientific and technological achievements makes me desperate. "
E.O. Wilson, a social biologist at Harvard University.
"In terms of environmental protection, marine protection is relatively backward. Because human beings have always thought that the ocean is so huge and rich, it is hard to imagine how human activities will affect such a behemoth. Unfortunately, we have caused irreparable damage to the ocean. "
Jane? Lubchenko, marine ecologist, University of Oregon, USA
"We must admit that in the past 10 years, human understanding of atmospheric chemical composition has improved a lot. Now almost everyone knows the word "greenhouse gas", and also knows that the exhaust gas emitted by factories and cars causes global warming. However, people are still ignorant of other hazards of' greenhouse gases', just like 10 years ago. "
Shirley? Roland, atmospheric chemist, University of California, Avon.
"When humans grow crops, they also destroy the topsoil of the soil. A large amount of topsoil was scraped up and then washed into the sea with the river. In the ocean, pesticides and insecticides are constantly accumulating, which is increasingly harmful to marine ecology. The key to solving this problem is that human beings should change the types of crops planted and have a variety of deeply planted plants, which is conducive to soil and water conservation. "
Wes? Jackson, a crop geneticist, said: "Greenhouse gases have increased the atmospheric temperature and ocean water temperature." Once the water temperature of the ocean rises, it will be a global disaster, because the movement of ocean currents will make the water temperature of the oceans all over the world as high. "
Richard? Barber, Duke University marine cartographer.
"Synthetic chemicals not only bring convenience to human life, but also interfere with hormones. Synthetic chemicals are everywhere on the earth, affecting the reproduction and development of human beings and all wild animals. But no country can ban synthetic chemicals from appearing in shopping malls, and we will continue to bear the side effects they bring. "
—— Ke Erpeng, Director of Wildlife and Pollutants Department of WWF
"On the issue of human attitude towards nature, the' Earth Summit' can be said to be a turning point. I hope people can realize that the protection of species diversity and the protection of natural environment such as wetlands and forests will affect the future operation mechanism of the earth. "
Hal? Munny, an environmental biologist at Stanford University, said
Seven well-meaning warnings
"If human beings continue their current behavior without making any changes, then by the end of 2 1 century, the species on the earth will be reduced by half. If these data can't change human behavior, what else can warn humans? "
E.O. Wilson, a social biologist at Harvard University.
"When asked,' What do you get from nature?' At that time, most people's answers were food, fiber, drugs and genes. But most people don't know about other services provided by the ecosystem. It purifies air and water, regulates climate, enriches barren soil and controls pests and pathogens. Only when we lose these services will we realize their value. "
Jane? Lubchenko, marine ecologist, University of Oregon, USA
"The El Ni? o phenomenon has raised people's vigilance, but no one can say when the next El Ni? o will come again. No one knows whether its consequences are gradual or sudden. If it is a mutation, it is naturally not prepared to give human beings any chance. "
Shirley? Roland, atmospheric chemist, University of California, Avon.
"The relationship between agriculture and wildlife has always been concerned, but the relationship between agriculture and the ocean has not received enough attention. It has been warned before that the wild world will be destroyed if agriculture is not controlled. Now I want to warn that if agriculture is not controlled, the ocean will be finished. "
Wes? Crop geneticist Jackson, "100 years ago, when a hurricane hit human beings, people at that time would only ask the government,' What the hell is going on?' Now, the government has been able to predict hurricanes, understand the intensity and direction of hurricanes, and minimize people's losses. /kloc-what we need after 0/00 years is that the government should also understand other extreme natural disasters. "
Richard? Barber, Duke University marine cartographer.
"Now there is enough evidence to prove that chemicals can enter the uterus, affecting the development of the human brain and the formation and function of the immune system. Humans need smart descendants and wise decision makers. "
—— Ke Erpeng, Director of Wildlife and Pollutants Department of WWF
"History has proved that the opinions of a few people can awaken the attention of the public and then change the direction of social development. Now that scientists are United as never before, we will present more and clearer evidence to make the public and policy makers change their minds. "
Hal? Munny, an environmental biologist at Stanford University, said
7 ecological paradise
kruger national park
Kruger National Park, located in South Africa, consists of endless prairies and bushes, and is the place with the largest concentration of mammals in the world. The history of Kruger National Park can be traced back to 1898. At that time, it was a hunting area. For the convenience of hunting, there were 147 kinds of wild mammals, including cheetah and white rhinoceros. There are more than 500 kinds of birds. Later, in a rather innovative concept at that time, Kruger was called the national park for short.
Tubataha Coral Reef National Park
This is an ecological reserve located on the remote coast of the Pacific Ocean, aiming at protecting marine fish. Tubataha Reef National Park was established in 1988, with the aim of limiting local uncontrolled fishing activities. Tubataha Reef National Park covers an area of 330 square kilometers, where more than 450 kinds of marine fish live comfortably. In Tubataha Reef National Park, any fishing activity is illegal. Unfortunately, there are few such marine protected areas in the world.
Prespa park
Prespa Park is a transnational nature reserve, which was established in 2000. In 2000, Albania, Greece and Macedonia signed an agreement to establish a nature reserve among the three countries. Prespa Park mainly protects the wetland resources in this area. There are more than 160 kinds of birds living here, and hundreds of other birds pass by here or will stay here for a short time. Now Prespa Park has become the last paradise for many rare birds.
Bahuay Ason National Park
The Bahia Sone National Park in Peru is the largest forest reserve in the world. Bahia Sonene National Park covers an area of 1 1,000 square kilometers, where there are dense forests. In the reserve, all acts of sabotage are strictly prohibited. In addition, Bahia Sonene National Park also protects the water resources of the three rivers flowing through the park, and fishing in these rivers has been banned since 2000. In this green world, there are more than 200 species of mammals, more than 900 species of birds and 1200 species of butterflies.
Nahani National Park
The Nahani National Park in the northwest of Canada covers an area of 4,760 square kilometers and protects the most rugged and natural land in Canada. Nahani National Park has no roads and no traces of human activities. There are many natural wonders here, including the natural grand canyon and the magnificent waterfall with a drop of 92 meters (the drop of this waterfall is twice that of the world-famous Niagara Falls). However, the Canadian government prohibits the development of the natural beauty here as a tourist resource, and only about 900 explorers enter Nahani National Park every year. Nahani National Park, founded in 1976 and 1978, was selected as a world natural heritage by the United Nations. Among many national parks and nature reserves, Nahani National Park is unique.
Royal Chitwan National Park
The Royal Chitwan National Park, located on the border between Nepal and India, is a very distinctive nature reserve in South Asia. Here, crocodiles swim freely in the river, and rare mammals including Bengal tigers also live here. Since the establishment of 1973, Royal Chitwan National Park, which belongs to the Royal Nepalese, has become a local tourism project, and the number of tourists has increased from 1000 per year in 973 to more than 1000 per year now. But this is not a good thing for nature reserves, but fortunately, the species and number of mammals here are increasing year by year.
Gualugo triangle
Goualougo Triangle is a protected area, which successfully combines commerce and nature conservation. This famous forest reserve in Africa is also a stage for big logging companies to perform. Logging companies have proved to the world that they don't always play the role of saboteurs. In fact, in the Goualougo Triangle, when logging companies gain benefits, the regeneration of forest resources is also guaranteed. Goualougo Triangle is the largest nature reserve in the Democratic Republic of Congo, where the density of gorillas and chimpanzees is the highest in the world.