1. Impact on climate
As the temperature rises, it is expected that the incidence of floods, droughts, fires and heat waves will also increase in some areas.
-IPCC 1995 report
If this situation continues and develops further, the whole territory of some countries will eventually become uninhabitable.
-Mutton
No one can say for sure how serious the harm caused by releasing more carbon dioxide and greenhouse gases into the atmosphere in the future will be. Scientists are estimating the harm caused by climate change. According to the current technical level, the formation and digestion mechanism of carbon dioxide in the atmosphere can only be clarified in 2004, and how the greenhouse effect is produced can be clarified. Only in 2006 can the sea level rise caused by global warming be accurately predicted. However, it will not be until 2050 that we can really understand all this. Obviously, scientists and politicians will not wait for further results before taking preventive measures. The present observation and research results should be made public, so that people will not have to swallow the bitter fruit after 50 years.
The greenhouse effect has been working since the formation of the earth. If there is no greenhouse effect, the surface of the earth will be extremely cold, the temperature will drop to MINUS 20 degrees Celsius, the ocean will freeze and life will not form. Therefore, we are not faced with the problem of whether there is a greenhouse effect, but the problem that human beings emit a lot of greenhouse gases into the atmosphere by burning fossil fuels, which leads to the greenhouse effect and the rapid change of the earth's climate.
What impact will the greenhouse effect have? Academician Huang said: "Due to the burning of fossil fuels and the deforestation of a large number of forests, the concentration of carbon dioxide in the earth's atmosphere has increased. Due to the greenhouse effect of carbon dioxide and other gases, the global average ground temperature has increased by about 0.3-0.6 degrees Celsius in the past 100 years, and it is expected to increase by 1-3 degrees Celsius in 2030. "
When the global average temperature rises 1 celsius, great changes will occur: sea level rises, glaciers in mountainous areas retreat, and the snow area shrinks. As the global temperature rises, it will lead to unbalanced precipitation, with precipitation increasing in some areas and decreasing in some areas. For example, in the Sahel region of West Africa, severe drought began at 1965; Since 1965, the precipitation in North China has decreased year after year. Compared with 1950s, the precipitation in North China decreased by 1/3, and the water resources decreased by 1/2. The drought-stricken area in China is about 400 million mu every year. In normal years, irrigation areas in China lack 30 billion cubic meters of water every year, and cities lack 6 billion cubic meters of water.
Due to the rising temperature, the global sea level has been rising at a rate of 1-2 mm per year in the past 100 years. It is predicted that the sea level will continue to rise by 30-50 cm by 2050, which will flood a large number of low-lying areas along the coast. In addition, due to climate change, climate disasters such as drought, flood and low temperature have intensified, resulting in global economic losses of more than tens of billions of dollars every year.
Therefore, the prediction of global climate change has not only become an important international scientific research topic, but also become the basis for our government to formulate policies and make economic construction decisions. Especially at the United Nations Conference on Environment and Development in June 1992, many countries signed the Framework Convention on Climate Change, and held the first Conference of the Parties in March 1995, which shows that global climate change has become an important scientific and environmental policy issue that our government must consider in order to promote its social and economic sustainable development.
As early as 1987, climate analysis showed that the increasing famine in African countries such as Ethiopia, Sudan and Somalia was consistent with the drastic changes in rainfall patterns. According to Agence France-Presse reported on April 27th, the Ogaden region in southern Ethiopia is a semi-desolate region, inhabited by about 3 million nomads. It hasn't rained for three years, and cows, sheep and even camels are dying of thirst. 1984- 1985 drought, nearly1100,000 people died. Now, 8 million people are waiting for emergency food aid. Comparing the climate measurement data of the past century and a half with the great changes of precipitation pattern in recent decades, the conclusion is that "the precipitation has not changed until the 1950s, and in the 1950s, after a relatively large rainfall period, the rainfall in North Africa and the Middle East has been greatly reduced." In the past 40 years, droughts have continued and appeared more frequently. During the same period, "precipitation in Europe increased significantly". The trend of temperature change in these 40 years is one of the factors that cause repeated and lasting famine. Researchers worry that this trend is only an early result of global warming.
According to the data of the Spanish Meteorological Bureau, the beginning of 2000 was the driest winter in Spain since 1947. It is impossible to restore a large amount of planting area, and the situation will get worse in the coming months. The reservoir capacity is only 50%, and 80% of the water consumption has been used for agriculture. In fact, at present, 1 person in every seven Europeans cannot drink tap water. UNESCO said: "Water shortage will be one of the main problems in the next 25 years, so we must immediately change the current habits that lead to the deterioration of the ecosystem."
Climate expert Lamb said, "If this situation continues and develops further, the whole land of some countries will eventually become uninhabitable." . Although climatologists are still reluctant to clearly link global warming with these disasters, it does not affect an inevitable conclusion that no matter what the causes of climate change are, there are still some fragile societies suffering greatly from the changes in climate patterns in modern and affluent global civilization. At present, other parts of the world can't come up with a real solution to the suffering people except tinkering. Moreover, although almost all the scientific circles in the world are shouting loudly that the current model of human civilization is causing great changes in the climate conditions of the earth, and the consequences are likely to be several times that experienced by mankind in the past 10000 years, we are still at a loss as to the main causes of the disasters that are forming.
In fact, this result has been clearly felt now, as stated in the IPCC 1995 report: "As the temperature rises, it is expected that the incidence of floods, droughts, fires and heat waves in some areas will also increase."
2. Glacier melting
Even if the glacial meltwater dries up within 60 to 100 years, the scope of this ecological disaster will be shocking.
"Hasning said.
If the global warming trend is not controlled, nearly 20% of Bangladesh may be flooded in 15.
-Saida Chowdhury
1998 is the hottest year on record in the history of the eastern United States. This year, 2850 square kilometers of Antarctic ice sheet broke away from Wilkins and Larsen ice shelves. Other parts of the huge Antarctic ice sheet are also fully retreating.
Castaing Mountain is the only mountain in hot Asia with perennial snow on its top. However, in recent centuries, the glaciers in Casta have obviously shrunk, resulting in an increase of about 100 meters of snow line.
In addition to the ice sheets in polar regions, Himalayan glaciers are the largest part of ice bodies in the world, with a total of about 6,543,800+0.5 million glaciers. The meltwater of these glaciers is the source of the Indus and Ganges rivers, the oldest rivers in the world. If the water sources of these two rivers are exhausted or gradually reduced to a trickle, the basic elements of agricultural society will be completely destroyed.
In recent years, due to the emission of "greenhouse" gas and the generally recognized greenhouse effect, it has been observed that the alpine glaciers from Patagonia to Switzerland are melting. In South Asia, the question is not whether glaciers are melting, but how fast they are melting. Although many adverse effects of global warming may not become very serious before the end of 2 1 century, glacial meltwater in Nepal, India, Pakistan, China and Bhutan may soon bring people trouble.
A research report of the International Snow and Ice Commission (ICSI) pointed out: "The glaciers in the Himalayas are retreating faster than anywhere else in the world. If the current melting rate continues, these glaciers are likely to disappear before 2035. " Said Ha Bosco Wong, head of the International Snow and Ice Commission, said: "Even if the meltwater of glaciers dries up within 60 to 100 years, the scope of this ecological disaster will be shocking."
Glaciers in the eastern Himalayas in the Ganges River basin have melted the most, and those distributed on the "roof of the world" from Bhutan to Kashmir have retreated the fastest. Take the 3-mile-long barna Glacier as an example. This glacier is one of many glaciers formed by the collision between the Indian subcontinent and the Asian continent 40-50 million years ago. Starting from 1990, it retreated half a mile. After the severe sub-arctic winter in 1997, scientists had predicted that this glacier would expand, but it retreated further in the summer of 1998.
Saida Chowdhury, Minister of Environment and Forests of Bangladesh, pointed out: "If the global warming trend is not controlled, nearly 20% of Bangladesh may be flooded in 15."
Ruby Lun, a researcher and climate expert at the Northwest Pacific National Laboratory in Washington State, found that the snowfall in the mountains of Oregon and Washington State from late/kloc-0 to late March next year will be transformed into rainfall, thus raising the average snow line of more than 900 meters to 1250 meters. This will not only turn the ski resorts in the central Cascade Mountains into mud, but also bring great disaster to the farmers on the east side of the arid mountains, because these farmers rely on the melting snow and ice on the mountains in spring to irrigate their apple trees and wheat.
This disease is rampant.
As the climate warms, some tropical diseases will spread to colder regions. The higher altitude environment is also more and more conducive to the survival of mosquitoes, plasmodium and other microorganisms it carries.
Paul Epstein
Paul Perstein of the Institute of New and Recurrent Diseases of Harvard University noticed that plants also moved with the snow line, and plants on mountain peaks all over the world were moving upwards. With the warming of mountain peaks, the higher altitude environment is more and more conducive to the survival of mosquitoes and microorganisms such as plasmodium.
After 1985, infectious malaria appeared in Gaohaibo area of Rwanda, Zambia, Ethiopia, Swatulan and Madagascar. 1988 An epidemic in the highlands of Madagascar killed more than 654.38+10,000 people. Irving Jay Yuan-sen, a meteorological impact expert in Greenpeace, believes that the increase in temperature and rainfall, coupled with the increase in drug resistance, has led to the prevalence of these diseases.
Climate is the key factor for the upward and outward spread of diseases such as malaria, yellow fever and dengue fever, because it not only affects the habitat of pests and diseases, but also affects the infectivity of diseases themselves. Anopheles mosquitoes that transmit malaria usually need an average temperature of 15.5 degrees Celsius to survive in winter. Activity and infection requirements of plasmodium 17.75℃. If the average temperature rises by 2.5 to 3.7565,438+07.75 degrees Celsius, the spread speed of dengue fever will double. At the same time, there are Aedes mosquitoes carrying yellow fever and dengue fever, both of which were previously confined to the latitude of about 35 degrees on both sides of the equator. Global warming will expand its activities to new york, Chicago, Beijing, Istanbul and Madrid.
This is not sensational. 1In July, 1999, West Nile virus landed in the western hemisphere for the first time and attacked new york City, which greatly shocked citizens and medical and health institutions. The authorities used helicopters and ground personnel to spray pesticides on a large area in the city to eliminate disasters and diseases. Epidemiologists and health experts who have been tracking the disease for a long time blame the outbreak of the disease on the impact of large-scale and long-term changes in the global climate on the local climate. Experts pay more and more attention to the impact of global warming on human health, and remind people that they should learn from the outbreak of new diseases and their relationship with climate change. According to the report of 2000 1 month, after the influenza epidemic occurred in California and Arizona on the west coast, it occurred in 19 states including new york, Pennsylvania, New Jersey, Virginia, Maryland and Washington, D.C.. The last influenza was caused by a virus called "Sydney influenza A", and the mortality rate caused by influenza is on the rise in the United States. According to the data of one week 122 American cities, the number of people who died of influenza or pneumonia accounted for 7.8% of the total deaths. This is no less than a warning to the world's major carbon dioxide emitters in 2000.
Since 1987, tropical infectious diseases such as West Nile virus, malaria and yellow fever have broken out in Florida, Mississippi, Texas, Arizona, California and Colorado in the United States, which has repeatedly confirmed experts' scientific inference that some tropical diseases will spread to colder regions due to climate warming.
4. New Ice Age
At present, the extinction rate of species has "reached half of the level of a mass extinction in geological history".
David Tillman
Another study on global warming is even more surprising. As the Arctic ice sheet melts, rainfall increases and wind types change, a large amount of fresh water is flowing into the North Atlantic, thus destroying the Gulf Stream. It is these warm currents that bring warm surface water from the Caribbean to the northwest of Europe, making Europe a warm climate. Once the Mexican warm current is cut off due to global warming, the temperature in northwest Europe may drop by as much as 5-8 degrees Celsius, and Europe may face a new ice age!
The research was conducted by the Scottish Marine Laboratory in Aberdeen, which analyzed more than 65,438+07,000 salinity measurements from Orchid Islands to Faroe Islands waters since 65,438+0893. In the past 20 years, the salinity and concentration of deep seawater flowing to the south have become smaller and smaller, which indicates that more fresh water has flowed into the region from the North Atlantic. These new data fully prove the computer model designed by German scientists about three years ago for the first time.
To understand the seriousness of this problem, in the words of Edward O. Wilson, a biologist at Harvard University, the current extinction rate has "reached half the level of a mass extinction in geological history".
The content of carbon dioxide in the atmosphere is rising sharply, and the world population will reach 654.38+000 billion before 2050. David Tillman of the University of Minnesota said: "Our world is moving towards replacing the existing free natural resources with man-made facilities. However, we haven't mastered the knowledge about natural ecosystems. In the Permian extinction 245 million years ago, 96% of species became extinct. Later, with the emergence of many new species, the earth finally recovered its rich population, but this process has gone through 100 million years. Wilson said: "Some people think that nature will revive everything that human beings have destroyed." As the saying goes, "As long as there is enough time, everything can happen." Maybe nature can really restore everything, but this long process is meaningless to modern human beings anyway.
Mark Twain once said that the most touching feature of the weather is its change. 1 After many centuries, we are still trying to predict the weather accurately, but we have little effect in controlling the climate. However, the damage to the environment is unprecedented.
Michael Michella, director of the American Global Change Research Program, said that maybe one day humans will have to seriously consider doing a completely different climate experiment. Global warming is caused by burning chemical fuels and emitting excessive greenhouse gases. One way to solve this problem is to set a huge mirror in space to deflect the resolution of sunlight. However, as Ronnie Arbiza, director of environmental prediction at Rutgers University in New Jersey, said, "The idea of controlling climate exists only in science fiction". We must do our best to control the climate in science fiction.
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