Is it getting cold this year?

That kind of weather is unlikely to appear the day after tomorrow. That's from the movie. Scientists have no final answer about whether the global climate is getting lower or higher. But many people agree with the greenhouse effect.

Greenhouse effect (Spanish Efecto Invernadero) refers to the heat insulation effect caused by the lack of heat exchange between the enclosed space transmitting sunlight and the outside world, that is, the short-wave radiation of the sun can penetrate into the ground through the atmosphere, but the long and short radiation released after the ground warms is absorbed by substances such as carbon dioxide in the atmosphere, thus producing the effect of atmospheric warming. Carbon dioxide in the atmosphere is like a thick layer of glass, which makes the earth a big greenhouse. It is estimated that if there is no atmosphere, the average surface temperature will drop to -23℃, while the actual average surface temperature is 15℃, which means that the greenhouse effect will increase the surface temperature by 38℃.

The greenhouse effect, also known as the "greenhouse effect", is a common name for the atmospheric heat preservation effect. The increase of carbon dioxide concentration in the atmosphere prevents the loss of heat on the earth and makes the earth feel the rise of temperature. This is the famous "greenhouse effect". Destroy the normal relationship between the atmosphere and the ground, absorb the infrared radiation released by the earth, just like a "greenhouse", and the gas that raises the temperature of the earth is called "greenhouse gas". Carbon dioxide is the largest greenhouse gas, accounting for about 0.03% of the total capacity of the atmosphere. Many other trace gases also produce greenhouse effect, some of which are stronger than carbon dioxide.

The atmosphere can make the short-wave radiation of the sun reach the ground, but the long-wave radiation emitted by the ground is absorbed by the atmosphere, which raises the temperature of the ground and the lower atmosphere. Because its function is similar to the greenhouse for cultivating crops, it is named the greenhouse effect. If this effect does not exist in the atmosphere, the surface temperature will drop by about 330℃ or more. On the other hand, if the greenhouse effect continues to strengthen, the global temperature will continue to rise year by year. Since the industrial revolution, carbon dioxide and other heat-absorbing greenhouse gases emitted into the atmosphere by human beings have increased year by year, and the greenhouse effect of the atmosphere has also been enhanced, which has caused a series of serious problems such as global warming and attracted the attention of all countries in the world.

In addition to carbon dioxide, methane, ozone, chlorofluorocarbons, water vapor and other gases that play an important role in the greenhouse effect. With the rapid increase of population and the rapid development of industry, the carbon dioxide discharged into the atmosphere has also increased accordingly; Because of a large number of deforestation, the carbon dioxide that forests should absorb in the atmosphere has not been absorbed, and the greenhouse effect has been continuously enhanced because of the gradual increase of carbon dioxide. According to analysis, in the past two hundred years, the concentration of carbon dioxide has increased by 25%, and the average temperature of the earth has increased by 0.5℃. It is predicted that by the middle of the next century, the average temperature on the earth's surface will rise by 1.5-4.5℃, especially in the middle and high latitudes.

The air contains carbon dioxide, which has remained basically unchanged for a long time in the past. This is because the carbon dioxide in the atmosphere is always in a dynamic equilibrium state of "increasing while consuming". 80% of carbon dioxide in the atmosphere comes from the breathing of people, animals and plants, and 20% comes from the burning of fuel. 75% of carbon dioxide scattered in the atmosphere is absorbed by groundwater and atmospheric precipitation such as oceans, lakes and rivers and dissolved in water. Another 5% of carbon dioxide is converted into organic matter through plant photosynthesis and stored. This is why carbon dioxide accounts for 0.03% (volume fraction) of air composition for many years.

However, 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. 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. 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. The increase of carbon dioxide content in the air changed the temperature of the earth.

In the air, nitrogen and oxygen account for the highest proportion, and both of them can transmit visible light and infrared radiation. But carbon dioxide can't. It cannot penetrate infrared radiation. Therefore, 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. But if the carbon dioxide content is too high, it will make the earth seem to be in a pot, and the temperature will gradually rise, forming a "greenhouse effect." Besides carbon dioxide, there are other gases that can also 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.

If the carbon dioxide content doubles, the global temperature will increase by 3℃ ~ 5℃, and the polar regions may increase by 10℃, and the climate will be obviously warmer. Rising temperature will lead to increased rainfall in some areas, drought in some areas, increased intensity and frequency of hurricanes and intensified natural disasters. What is even more worrying is that due to the rising temperature, glaciers in polar regions will melt and sea levels will rise, and many coastal cities, islands or low-lying areas will face the threat of rising sea water or even be swallowed up by sea water. In the late 1960s, a drought lasted for six years in the pastoral areas of sub-Saharan Africa. Due to lack of food and pasture, livestock were slaughtered, and more than 6.5438+0.5 million people died of hunger.

This is a typical example of the "greenhouse effect" bringing disaster to mankind. Therefore, we must effectively control the increase of carbon dioxide content, control population growth, use fuel scientifically, strengthen afforestation, green the earth, and prevent global disasters caused by the greenhouse effect.

Scientists predict that the global average temperature will rise by 1 times for every increase of carbon dioxide in the atmosphere in the future, and the temperature increase in polar regions will be about three times higher than the average. Therefore, rising temperatures will inevitably melt polar ice, leading to rising sea levels. Sea level rise has a very serious impact on human society. If the sea level rises 1 m, the land directly affected is about 5× 106 km2, the population is about 1 billion, and the cultivated land accounts for about 1/3 of the total cultivated land area in the world. If extreme storm surge and salt water intrusion are taken into account, the coastal areas below 5 meters above sea level will be affected, and the population and grain output of these areas account for about 1/2 of the world. Some coastal cities may move inland, and most coastal plains will be salinized or swamped, which is not suitable for grain production. At the same time, it will also cause disasters to the middle and lower reaches of the river. Seawater intrusion will cause the river water level to rise, sediment deposition to accelerate, flood threat to intensify, and the downstream environment of the river to deteriorate sharply. The greenhouse effect and global warming have attracted worldwide attention. At present, the international convention on climate change is being promoted, and reducing carbon dioxide emissions has become the general trend.

Scientists predict that if I start cutting trees moderately now, global warming will be reduced by 5% by 2050.

Greenhouse has two characteristics: the temperature is higher than that outside, and it does not dissipate heat. Glass greenhouses and vegetable greenhouses that can be seen in life are typical greenhouses. Glass or transparent plastic film is used as a greenhouse, so that sunlight can directly shine into the greenhouse and heat the indoor air, and the glass or transparent plastic film can prevent the indoor hot air from emitting outward, thus keeping the indoor temperature higher than the outside and providing conditions conducive to the rapid growth of plants.

result

1) the increase of pests and diseases on the earth;

2) sea level rise;

3) Abnormal climate, increasing ocean storms;

4) The land is dry and the desertification area increases.

Scientists predict that if the earth's surface temperature continues to rise at the current rate, by 2050, the global temperature will rise by 2-4 degrees Celsius, polar icebergs will melt greatly, resulting in 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.

The greenhouse effect will make prehistoric deadly viruses threaten human beings.

American scientists have recently warned that due to the melting of Arctic ice due to global temperature rise, prehistoric deadly viruses frozen for more than100000 years may reappear, leading to global epidemic panic and seriously threatening human life.

Scientists at Syracuse University in New York pointed out in the latest issue of Scientist magazine that they had discovered a plant virus TOMV earlier. Because it is widely spread in the atmosphere, it is inferred that this virus has also been found in the Arctic ice sheet. So the researchers extracted four pieces of ice from Greenland, ranging in age from 5 million years to 6.5438+0.4 million years, and found the TOMV virus in the ice. Researchers say that the surface of the virus is surrounded by a solid protein, so it can survive in adversity.

This new discovery makes researchers believe that a series of epidemic viruses such as influenza, polio and smallpox may be hidden deep in the ice. At present, human beings have no resistance to these primitive viruses. When the global temperature rises and the ice melts, these viruses buried in the ice for thousands of years or more may resurface and form an epidemic. Scientists say that although they don't know the survival hope of these viruses or the chance to adapt to the ground environment again, they certainly can't rule out the possibility of the virus coming back.

origin

The greenhouse effect is mainly caused by the excessive burning of coal, oil and natural gas in modern industrial society, which releases a lot of carbon dioxide gas into the atmosphere after burning.

Carbon dioxide gas has the functions of heat absorption and heat insulation. The result of its increase in the atmosphere is the formation of an invisible glass cover, which prevents the heat radiated by the sun to the earth from spreading to outer space, and as a result, the surface of the earth becomes hot. Therefore, carbon dioxide is also called greenhouse gas.

Human activities and nature also emit other greenhouse gases, such as chlorofluorocarbons (CFCs), methane, low-level ozone and nitrogen oxides. On earth, plankton in the ocean and forests on land, especially tropical rainforests, can absorb a lot of carbon dioxide.

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.

New theory

Since 1975, the average temperature of the earth's surface has increased by 0.9 degrees Fahrenheit, and global warming caused by greenhouse effect has become the focus of world attention. The academia has always recognized that carbon dioxide produced by the burning of coal, oil and natural gas is the chief culprit of global warming. However, after decades of observation and research, Dr. james hanson from Goddard Institute of Space Studies in the United States put forward a new view that greenhouse gases are mainly carbon dust and other substances, not carbon dioxide.

Carbon particle dust is a kind of solid particulate matter, which is mainly caused by the low carbon utilization rate when burning high-carbon fuels such as coal and diesel. It not only wastes resources, but also causes environmental pollution. A large number of carbon particles gather in the troposphere, which leads to the accumulation of clouds, and the accumulation of clouds is the beginning of the greenhouse effect, because 40% to 90% of the ground heat comes from the atmospheric reverse radiation generated by clouds. The thicker the clouds, the less heat will spread out, and the hotter the earth will be.

Dr. Hansen recorded the changes in the contents of various greenhouse gases, and found that the content of carbon dioxide nearly tripled between 1950 and 1970, but decreased from 1970s to the end of 1990s. It is difficult to explain the worsening global warming phenomenon with the current popular theory.

Dr. Hansen believes that in addition to carbon dust, there are other gaseous substances that can cause the greenhouse effect, such as ozone in the troposphere (normal ozone should be concentrated in the stratosphere), methane and highly toxic chlorofluorocarbons. However, the control of these pollution sources is relatively difficult. Fortunately, the content of non-carbon dioxide greenhouse gases has decreased in recent decades. If the contents of methane and ozone in the troposphere can also be reduced year by year, the change of the average temperature on the earth's surface will be almost zero in the next 50 years.

Carbon dust is not inevitable. With the continuous improvement of the quality of internal combustion engine, even the appearance of vehicles without internal combustion engine can reduce the residual carbon particles. If Dr. Hansen's theory can be established, it will bring new hope for the earth to cool down and hope that the earth will have a fever as soon as possible.

Before the industrial revolution, the content of carbon dioxide in the atmosphere was 280ppm. According to the current growth rate, by 2 100, the content of carbon dioxide will increase to 550ppm, that is, it will almost double. Many meteorologists all over the world are trying to study how much the global average temperature will rise by 2 100 after the carbon dioxide content doubles.

At present, the concrete method is to design a numerical model to calculate according to the laws of atmospheric movement and physical state change. However, due to people's imperfect understanding of the law of atmospheric motion change, the calculation results of each model are often very different by using different simplified calculation methods. Therefore, in the 1980s, the American Academy of Sciences organized an evaluation committee to study and comprehensively evaluate the results of these models, and finally came to the conclusion that the global average temperature would increase by 3℃ after CO2 doubling, that is, 1.5℃, that is, 1.5℃-4.5℃. This is the figure used in the first report of the United Nations Intergovernmental Panel on Climate Change, the most authoritative organization on this issue.

In recent years, the simulation ability of climate model has been greatly improved, mainly considering the role of aerosols (tiny particles suspended in the air) in the atmosphere. Because when burning fossil fuels, it will release CO2, and at the same time, it will release huge aerosols such as sulfides. This aerosol will prevent some sunlight from reaching the ground, thus reducing the ground temperature and playing a role in cooling down. The IPCC estimated it to be -0.5 W/m2. That is, 1/3 is equivalent to the warming effect of CO2 (1.56W/m2), which is slightly greater than that of methane (+0.47W/m2). Mainly based on this improvement, in the second report published in 1996, IPCC changed the warming value of global average temperature after CO2 doubling of 2 100 from 1.5℃-4.5℃ to 1.0℃-3.5℃. The assessment report also pointed out that due to the huge thermal inertia of the ocean, the warming value of 2 100 will only be about 50%-90%.

However, the results of model calculation also show that the global average warming 1.0℃-3.5℃ is unevenly distributed around the world, but there is no or almost no warming in equatorial and tropical areas, and the warming is mainly concentrated in high latitudes, with the amount reaching 6℃-8℃ or even more. This will cause another serious consequence, that is, the ice sheets at the poles and Greenland will melt, causing sea levels to rise. The permafrost zone of the high-latitude continent in the northern hemisphere will also melt or thin, resulting in a large area of swamp. In addition, the volume expansion of seawater after ocean warming will also lead to sea level rise. In the first assessment report of IPCC, it is predicted that the sea level will rise by 70- 150 cm (corresponding temperature rise 1.5℃-4.5℃), and in the second assessment report, it will be 20% lower than the first assessment result (corresponding temperature rise 1.0℃-3.5℃). The IPCC's second assessment report also pointed out that the global sea level has risen by10-25cm since the end of 19, because the global average temperature has risen by 0.3℃-0.6℃.

The rise of global sea level will directly flood the coastal lowlands with dense population and developed industry and agriculture, with very serious consequences. 1995165438+1At the second Conference of the Parties to the United Nations Framework Convention on Climate Change held in Berlin in October, 44 small island countries formed the Alliance of Small Island States and called for the right to exist.

In addition, it is pointed out that the increase of CO2 will not only lead to global warming, but also lead to the adjustment of global atmospheric circulation and the expansion of climatic zones to the polar regions. The precipitation in mid-latitude areas, including northern China, will decrease, and evaporation will increase as the temperature rises, so the climate will become drier. The adjustment of atmospheric circulation, in addition to mid-latitude drought, may also cause climate anomalies and disasters in other parts of the world. For example, the intensity of typhoons at low latitudes will increase, and the source of typhoons will expand northward. Rising temperature will also cause and aggravate the epidemic of infectious diseases. Take malaria as an example. In the past five years, the incidence of malaria in the world has quadrupled. At present, about 500 million people in the world suffer from malaria every year, and more than 2 million of them die.

However, the greenhouse effect is not all bad. Because the coldest high latitudes have the greatest warming, agricultural areas will be greatly promoted to the polar regions. The increase of CO2 is also beneficial to the photosynthesis of plants and directly increases the yield of organic matter. It is also pointed out that in the historical period of China and the world, the warm period is mostly a prosperous period with more precipitation and shrinking arid areas, and so on.

Of course, there are also different views on the issue of atmospheric greenhouse effect. For example, some scientists used to think that the current numerical model is immature and the calculation results are too exaggerated; A rise of 0.3℃-0.6℃ in a hundred years is a normal climate change, which cannot be proved to be caused by the atmospheric greenhouse effect, and so on. Of course, this is a minority opinion.

However, the indisputable fact is that the concentration of CO2 in the atmosphere and the global temperature are increasing rapidly, and the increase of greenhouse gases will lead to global warming. If we wait until the problem is clearly perceived by human beings, it will often be difficult to reverse it, and it will be too late. Therefore, we must attach great importance to it now in order to take countermeasures to protect the atmospheric environment on which human beings depend.

Countermeasures

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.

Therefore, for today's plan, it is nothing more than doing everything possible to take countermeasures and try 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.

In fact, the whole world is working hard in this direction, and this situation is most likely to be realized. If this can be achieved, it is predicted that global warming can be suppressed by about 3% by 2050.

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. In this way, the greenhouse effect can be reduced by about 7%.

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. The reduction of fossil fuel consumption caused by this effort is estimated to reduce the greenhouse effect by about 5% by 2050.

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, and it is estimated that it will inhibit global warming by about 8% by 2050.

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.

Therefore, it is suggested to increase taxes in the order of natural gas, oil and coal. For example, in production, coal with high carbon dioxide emissions should be taxed at $0.50/10 billion joules in energy, while natural gas is only taxed at $0.23. In other words, the higher the carbon dioxide emissions, the heavier the tax on fossil fuels. As for consumption, the tax rate is set at 23% for coal and 0/3% for natural gas.

Of course, this is the only idea at this stage. But if put into practice, it is expected to provide about 5% inhibition on global warming by 2050.

6. Encourage the use of natural gas as the main energy source at present.

Because natural gas emits less carbon dioxide. Recently, Japanese cities generally use natural gas instead of liquefied gas, and this case is to further promote this movement. However, the effect of inhibiting warming is not too great, only about 1% at most.

Seven, steam locomotive exhaust restrictions.

Because the exhaust gas of cars and locomotives contains a lot of nitrogen oxides and carbon monoxide, it is hoped to reduce its emissions. Although this method can not directly reduce carbon dioxide, it can produce the effect of inhibiting other greenhouse gases such as ozone and methane. It is estimated that by 2050, it will share about 2% of the global warming suppression.

Eight, encourage the use of solar energy.

For example, promoting the so-called "sunshine plan" and so on. This kind of effort can relatively reduce the consumption of fossil fuels, so it has a direct effect on reducing the greenhouse effect. However, even if this plan is actively promoted, it will only inhibit the temperature rise to about 4% by 2050. Its effect does not seem to be as expected.

Nine. Develop alternative energy sources

Using biomass energy as a new clean energy. That is, the organic matter produced by plants through photosynthesis is used as fuel to replace the existing high-pollution energy sources such as oil.

Burning biomass energy will also produce carbon dioxide, which is the same as fossil fuel, but biomass can continuously absorb carbon dioxide from nature as raw materials, so it can become renewable energy and be recycled repeatedly to achieve the effect of inhibiting the growth of carbon dioxide concentration.