First of all, we know that carbon dioxide can prevent the surface heat from radiating into space and has the function of regulating the earth's temperature. Without carbon dioxide, the average annual temperature of the earth would be 20℃ lower than it is now. However, carbon dioxide is also the main cause of the greenhouse effect. On July 4th, 1988, an influential American magazine, Happiness, published an article, which attracted worldwide attention. The author believes that there will be a very bad climate in the 20th century, the temperature will rise higher and faster than ever before, the global climate will be chaotic and abnormal, and the world economy will be greatly affected. The main reason for the above situation is the burning of fossil fuels such as coal, oil and gasoline. The carbon dioxide produced by the combustion accumulates rapidly in the atmosphere, which is much less than that of carbon dioxide, but the same harmful gases such as chlorofluorocarbons also increase rapidly. In the earth's atmosphere, these gases play the role of greenhouse glass, allowing sunlight to enter and leaving heat. They absorb, rather than reflect, infrared radiation that can generate heat, thus increasing the temperature of the earth. Especially in recent decades, due to the rapid increase of population and the rapid development of industry, the carbon dioxide produced by breathing and burning coal, oil and natural gas has far exceeded the past level. According to statistics and calculations, the carbon emitted into the atmosphere by global combustion has been increasing slowly for six consecutive years, reaching 5.925 billion tons in 1994. . On the other hand, due to deforestation, a large number of farmland has been built into cities and factories, destroying vegetation and reducing the conditions for converting carbon dioxide into organic matter. The added carbon in the atmosphere is also between1.1-360 million tons. In addition, the surface water area is gradually shrinking, the precipitation is greatly reduced, the conditions for absorbing and dissolving carbon dioxide are reduced, the dynamic balance of carbon dioxide generation and transformation is destroyed, and the carbon dioxide content in the atmosphere is increased year by year. Since the middle of18th century, carbon dioxide and other greenhouse gases in water have reached an unprecedented concentration in the past160,000 years. The increase of carbon dioxide content in the air changed the temperature of the earth. This is the greenhouse effect. Of course, besides carbon dioxide, there are other gases that can cause the greenhouse effect. Among them, carbon dioxide accounts for about 75%, chlorofluoroalkanes account for about 15% ~ 20%, and there are more than 30 kinds of methane and nitric oxide. )
Understand the causes of the greenhouse effect, many of which are caused by human destruction. Due to the economic development, a large number of factories have been built, which has also brought about the consequences of a large number of polluted gases being discharged into the atmosphere. The demand for wood in production has led to the reduction of large areas of forests ... while civilization is progressing, the greenhouse effect is also intensifying. ...
Let's discuss the harm of the greenhouse effect again.
The greenhouse effect has the remarkable characteristics of wide influence range, complex restrictive factors and serious consequences. Global climate change is the direct result of the greenhouse effect. Therefore, the greenhouse effect is a major environmental problem facing mankind, which has attracted great attention from governments and scientists all over the world and has become the focus of attention and research by scientists and environmental workers. The impact of the greenhouse effect on the ecological environment mainly includes the following aspects.
I. Impact of sea level
Global warming has the following two effects on the ocean, leading to sea level rise.
(1) Global warming will cause the water temperature in the marine mixed layer to rise, and the thermal expansion energy generated by warming will significantly cause the sea level to rise;
(2) The rise of air temperature and seawater temperature will lead to a large number of melting polar ice sheets, and the melted ice sheets will enter the ocean, contributing to the rise of sea level. If the temperature rises sharply in the future, it will have a great impact on the polar regions. By then, polar glaciers and ice sheets will melt in large quantities, and their contribution to sea level rise will far exceed the contribution of thermal expansion of mixed layers. In the next century, the average speed of global sea level rise will be about 6 ″ per 10 year. It is predicted that the sea level will rise by 20 cm by 2030 and 65 cm by the end of the next century. This change in sea level will bring the following impacts and disasters to coastal areas:
(1) Submerged coastal land, resulting in waste of land resources, especially coastal cities and cultivated land resources.
(2) the reduction of fresh water resources and reserves.
(3) The living environment of marine organisms has been changed, and a large number of them have died or been forced to migrate, which has brought some damage to the fishery.
(4) beaches and coasts will be eroded;
5] The groundwater level rises, leading to soil salinization;
[6] seawater intrusion and flood intensification;
Once port equipment and coastal buildings are damaged, shipping will be affected;
(8) Coastal aquaculture will be affected;
Levies damage the water supply and drainage system;
⑽ The temperature zone changes, the cold and hot zone expands, and the temperate zone shrinks, causing damage to agriculture.
Second, the impact on agriculture.
The most obvious impact is in agriculture. With the increase of carbon dioxide concentration, the stomata (stomata through which gas and water vapor pass) of plants can receive the same amount of carbon dioxide as long as they are opened a little smaller, so that the water lost by evaporation of plants is reduced, and as a result, plants will grow bigger. The faster the crops grow, the faster the nutrients in the soil are absorbed, and farmers have to buy more chemical fertilizers. The quality of grain may decrease with the increase of carbon dioxide, because the carbon content of leaves may increase and the nitrogen content may decrease. In the greenhouse effect, pests and diseases are easy to spread, but the greenhouse effect will cause a series of environmental and climate problems, such as pest reproduction, increased drought, etc., which will fundamentally worsen the growing environment of crops, thus causing serious harm and being quite unfavorable to agriculture. Due to the increase of temperature, the start time of pest development may be advanced, and the reproductive generation of pests will also increase within one year. Under the new suitable environmental conditions, the population of some pests will increase exponentially, leading to an increase in the probability of repeated damage to farmland. On the other hand, with the warming of winter, pests and diseases are more likely to overwinter, and the sources of pests and diseases increase. More seriously, migratory pests of many main crops are more widely distributed and more harmful than today, and the anti-season breeding area of armyworm is greatly expanded. Due to the decrease of temperature difference between north and south, the initial peak period of migratory pests such as armyworm and rice planthopper will be advanced in spring, and the migration period to the south in autumn will be delayed, which will prolong the damage time. In addition, the migration path of migratory pests in spring and autumn will also affect the distribution area of their concentrated harm. Climate warming will change the geographical distribution of crop pathogens and spread diseases and insect pests. The extraordinary growth of weeds means that a large number of pesticides and herbicides have to be applied, which will aggravate environmental pollution. This requires more pesticide control. The pesticide industry means that our environmental pollution will be very serious.
The influence of greenhouse effect on plants is mainly manifested in two aspects: the influence of increasing co2 content on plant photosynthesis; Effects of climate warming on plants. Co2 is the basic raw material of plant photosynthesis. When the co2 content increases, the productivity of plants can be improved to some extent. As the temperature rises, some originally cold areas will become suitable for crop growth and expand the plant growth area, which is beneficial.
Third, the impact on forestry and animal husbandry.
Global warming has many effects on forestry and animal husbandry. The increase of carbon dioxide concentration will enhance the photosynthesis of natural vegetation, and the increase of temperature will prolong the growth period, so the yield of vegetation will increase; With the increase of temperature, the vegetation belt will move northward, that is, cold temperate forests or temperate grasslands will replace the current northern forests, while subtropical forests will be replaced by tropical forests; With the change of temperature and precipitation, the species of trees and grasses are likely to change, especially grasses. If an inferior grass can better adapt to the changed environment and quickly grow and occupy the grassland, it is likely to greatly reduce the productivity of the grassland. As the temperature rises, if there is no corresponding increase in precipitation, the air humidity may decrease, which increases the possibility of fire. At the same time, warm winter can reduce the overwintering mortality of pests, thus increasing the threat of pests.
Fourth, the impact on human health.
(1) Global warming directly leads to ultra-high temperature in some areas in summer, because heart disease and various respiratory diseases cause many deaths every year, among which newborns and the elderly are the most dangerous.
(2) Global warming leads to the increase of ozone concentration. Ozone in the lower air is a very dangerous pollutant, which can destroy lung tissue and lead to asthma or other lung diseases.
(3) Global warming leads to the spread of some infectious diseases. When a mosquito bites a person with an infectious virus, the virus will follow the blood into the mosquito to start reproduction, and then enter a healthy person through the next bite to complete the spread of the virus. In a certain temperature range, with the increase of temperature, the reproduction rate and bite rate of mosquitoes are greatly improved, and the reproduction and maturity rate of viruses in their bodies will also increase. The rising temperature at night and in winter greatly prolongs the life span and active area of mosquitoes, and increases the incidence of malignant infectious diseases such as malaria, scarlet fever, jaundice and encephalitis.
(4) Global warming will cause different natural disasters in different regions, which will directly lead to the reduction of grain production, threaten the hunger and malnutrition of local residents, and accelerate the spread of some water-borne viruses, such as encephalitis, dysentery and high fever.
The influence of verbs (abbreviation of verb) on climate.
Because greenhouse gases (carbon dioxide, methane, water vapor, etc. ) enhance the atmospheric inverse radiation, the global temperature will generally rise, making the tropical area almost uninhabitable; Strong convective weather is getting worse and worse. Strong convective weather such as hurricanes, tornadoes, hail, thunderstorms and strong winds occur frequently; The melting of the north and south poles affects ocean currents and changes the temperature of seawater, thus making the continental climate abnormal; Generally speaking, abnormal climate will lead to a series of disastrous weather, including drought, flood, lightning, hurricane, storm surge, sandstorm, frost and snowstorm. In turn, geological disasters such as mudslides and land subsidence are triggered.
Sixth, glaciers melt.
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 polar ice sheets, Himalayan glaciers are the largest part of ice bodies in the world, with about1.5000 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. Icebergs in the Arctic and Antarctic will melt greatly, leading to a sharp rise in sea level, and some island countries and coastal cities will be submerged, including several famous international cities: new york, Shanghai, Tokyo and Sydney.
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 Ice and Snow Committee, said: "Even if the meltwater of glaciers dries up within 60 to 100 years, the scope of this ecological disaster will be shocking."
Effects of Global Warming on Biodiversity
Global warming is not a new phenomenon. In the past 2 million years, the earth has experienced 10 cycles of alternating cold and warm. During the warm period, the polar ice sheet melted, the sea level was higher than today, and the species distribution extended to the polar regions and migrated to high altitude areas. On the contrary, during the transformation to Xinhua News Agency, the ice sheet expanded, the sea level dropped, and species moved to the equator and low altitude areas. There is no doubt that many species will go extinct in this process of repeated changes, and the existing species are the products of these changes. Can species adapt to past changes, but can they adapt to the future climate changed by human activities? This is an open question. But what is certain is that the natural fluctuation of latitude and longitude of global warming caused by human factors in the past is much faster, so the impact of this change on biodiversity will be enormous.
(1) Impact on temperate biodiversity As the temperature continues to rise, the north temperate zone and the south temperate zone will expand to the poles. Climate change will inevitably lead to species migration. However, according to the speed table of natural diffusion, many species seem to be unable to keep up with the rapid climate change at high migration speed. It is clear by comparing the species mobility of deciduous broad-leaved forests in eastern North America. After the recent Pleistocene Ice Age, the temperature rose and the trees moved back to North America at the speed of 10 ~ 40 km/world. According to the estimation that the temperature will rise 1.5 ~ 4.5℃ in 2 1 century, trees will move 5000 ~ 10000 km to the north. Obviously, it is impossible to spread at a speed of dozens of times in the natural state. Moreover, habitat fragmentation caused by human activities can only reduce species mobility. Therefore, many species with limited distribution or poor diffusion ability will undoubtedly go extinct during migration. Only widely distributed and easily diffused species can establish their own communities in new habitats.
(2) Impact on biodiversity of tropical rain forest. Tropical rainforests have the greatest species diversity. Although the impact of global temperature change on the tropics is far less than that on the temperate zone. However, climate warming will lead to changes in tropical rainfall and rainfall time, and forest fires and hurricanes will also become frequent. These factors will have a great influence on species composition and plant reproduction time, thus changing the structural composition of tropical rain forest.
(3) Impact on biodiversity of coastal wetlands and coral reefs Wetlands and coral reefs are ecosystems with rich biodiversity, but they will also be threatened by climate warming. Rising temperatures will melt alpine glaciers and shrink Antarctic ice. In the next 50 ~ 100 years, the sea level will rise by 0.2 ~ 0.9 meters or even higher. Sea level rise will inundate wetland communities in coastal areas. The sea level is changing so fast that many biological species have no time to migrate to suitable areas with the rise of sea water. In particular, houses, roads and flood control dams built in wetland areas will become direct obstacles to species migration.
Sea level rise is very harmful to coral reef species. Because corals have strict requirements on the combination of seawater illumination and water flow. If the sea water rises at the budgeted rate, even the fastest growing corals can't adapt to this change. In addition, the rising temperature of seawater will also do great harm to corals. This will cause a large number of corals to sink and die.
Generally speaking, there are two sources of greenhouse gases in the atmosphere: nature and human activities. The concentration of various greenhouse gases in the atmosphere increases, which leads to the strengthening of the greenhouse effect, and carbon dioxide is the most important gas that causes the greenhouse effect. The increase of greenhouse effect will lead to global warming, which will affect water resources, agriculture, animal husbandry and forestry. Sea level rise will flood many coastal cities and lowlands; It will make some areas dry and aggravate desertification; Biodiversity is decreasing. In a word, the change of global ecosystem will eventually affect human health and survival.
From these, we will see what harm the greenhouse effect will bring us. Are you scared? Worried? Can humans survive? We must take necessary measures to reduce the harm caused by the greenhouse effect.
Because the greenhouse effect is mainly caused by the excessive burning of coal, oil and natural gas in modern industrial society, these fuels will release a lot of carbon dioxide gas into the atmosphere after burning. Therefore, it is imperative to reduce carbon dioxide emissions. In order to reduce the excessive carbon dioxide in the atmosphere, on the one hand, people need to save electricity as much as possible (because power generation needs to burn coal) and drive less cars. On the other hand, protect forests and oceans, for example, don't cut down forests and prevent the oceans from being polluted, so as to protect the survival of plankton. We can also protect green plants by planting trees, reducing the use of disposable wooden chopsticks, saving paper (paper wood) and not trampling on the lawn, so that they can absorb more carbon dioxide to help slow down the greenhouse effect.
Although we can't come up with an effective solution so far, the next best thing is to try our best to curb the growth of emissions, and we can't leave it to fate.
First, the tentative target is 2050. If the current situation continues, it is estimated that the average temperature of the earth will rise by more than two degrees by combining the effects of various greenhouse gases. Once the temperature rises so sharply, the earth's climate will change dramatically.
So now human beings should try their best to take countermeasures and try their best to curb the upward trend. At present, international public opinion is constantly calling for this direction, and research institutions in various countries have also put forward various specific countermeasures.
Unfortunately, after carefully studying various schemes, so far, no one countermeasure has been found to solve the problem alone. Therefore, it is necessary for us to explore all the possibilities and comprehensively consider the effects of these countermeasures.
First, a total ban on chlorofluorocarbons.
Fluorocarbon is the abbreviation of chlorofluorocarbon, which is the general name of various nonflammable organic solvents such as fluorine and chlorine. It is an excellent cleaning agent for electronic products after welding and assembly. However, because it is not biodegradable and its specific gravity is very light, it will destroy the ozone protective layer around the earth after gradually rising and accumulating, which will attack the earth's ecological environment by cosmic rays and cause great crisis.
Second, measures to protect forests
Today, the global forests that depend on tropical rainforests for their livelihood are being seriously damaged by human beings. On the one hand, the effective countermeasures are to stop this uncontrolled forest destruction as soon as possible, on the other hand, to implement large-scale afforestation and strive to promote forest regeneration. At present, the carbon dioxide released into the atmosphere due to forest destruction is estimated to be about 1 ~ 2gt. Annual carbon emissions. If countries seriously promote the plan of controlling logging and forest regeneration, by 2050, the whole biosphere may absorb carbon dioxide equivalent to 0.7gt. carbon every year.
Third, the improvement of automobile fuel use.
Japanese cars have been upgraded in this respect, greatly improving the fuel consumption in the past. In the United States and other places, perhaps because of the rich oil layers, there is no obvious improvement in fuel-saving design, and the fuel consumption is still too high. Therefore, the cars produced in this area have full play in improving fuel design. Fourth, improve energy efficiency in other occasions.
Is to improve energy efficiency in other occasions. In today's human life, a lot of energy is used everywhere, especially in the heating and cooling equipment of houses and offices. Therefore, there is still room for substantial improvement in improving energy efficiency.
Five, the production and consumption of fossil fuels, tax in proportion.
In this way, manufacturers and consumers can be urged to be vigilant when using energy and avoid unnecessary waste. Its tax revenue can be used for forest protection and the development of alternative energy sources.
Once any fossil fuel is burned, it will emit carbon dioxide. However, its emissions will vary according to the types of fossil fuels. Because the main component of natural gas is methane, its carbon dioxide emission is lower than that of coal and oil. Similarly, in order to generate 1000 calories, coal must emit carbon dioxide equivalent to 0.098 grams of carbon; This is 0.085 grams of oil. If you switch to natural gas, you only need to discharge 0.056 g.
When we decide to do this project, the members of our group should first check the information to understand the causes, harm and corresponding countermeasures of the greenhouse effect and understand the project from different aspects. At the same time, we have gained a lot, not only knowing a lot of knowledge that we didn't know before, but also understanding the importance of the environment to us and the earth. From now on, we will pay attention to our own behavior, and strive to start from small things, protect the environment and care for the earth.