What is the Global Warming Greenhouse Effect?

The greenhouse effect, also known as the "flower house effect," is a popular name for the effects of atmospheric insulation. The atmosphere can make the solar short-wave radiation reach the ground, but a large amount of long-wave heat radiation emitted outward after the surface is heated is absorbed by the atmosphere, which increases the temperature of the ground and the lower atmosphere. Because its role is similar to that of a greenhouse for growing crops, it is named a greenhouse effect. Since the Industrial Revolution, the endothermic greenhouse gases such as carbon dioxide emitted by humans into the atmosphere have increased year by year, and the greenhouse effect of the atmosphere has also increased. This has caused a series of problems that have attracted the attention of countries around the world.

Greenhouse effect means that the enclosed space transmitting sunlight is

Not every gas in the atmosphere can strongly absorb long-wave ground radiation. The greenhouse gases in the earth's atmosphere are called greenhouse gases, mainly including carbon dioxide (CO ₂ ), methane, ozone, nitrous oxide, freon, and water vapor. They absorb almost all long-wave radiation from the ground, and only a very narrow section absorbs very little, so they are called "window zones". It is precisely through this window that the earth returns 70% of the heat obtained from the sun to the space in the form of long-wave radiation, thereby maintaining the ground temperature unchanged. The greenhouse effect is mainly due to the increase in the amount and variety of greenhouse gases by human activities. Make this 70% drop, and the remaining heat will warm the earth.

However, although CO ₂ and other greenhouse gases have a strong ability to absorb ground long-wave radiation, their amount in the atmosphere is very small. If the atmospheric state with a pressure of one atmosphere and a temperature of 0 ° C is called the standard state, the entire atmosphere of the earth is compressed to this standard state, and its thickness is 8000 meters. At present, the content of CO ₂ in the atmosphere is 355 ppm, which is 355 parts per million. When converted to a standard state, it will be 2.8 meters thick. In the 8000-meter-thick atmosphere, this 2.8-meter-thick point is accounted for. The methane content is 1.7 ppm, which corresponds to a thickness of 1.4 cm. The ozone concentration is 400 ppb (ppb is one thousandth of a ppm), which is only 3 millimeters thick after conversion. Nitrous oxide is 310 ppb and 2.5 mm thick. There are many kinds of Freon, but Freon12, which contains the most amount in the atmosphere, is only 400ppt (ppt is one thousandth of ppb), and the standard state is only 3 microns. This shows that there is little greenhouse gas in the atmosphere. Because of this, artificial release without restrictions will easily cause rapid global warming.

As early as 1938, British meteorologist Carinda analyzed the scattered CO ₂ observations around the world at the end of the 19th century and pointed out that the concentration of CO ₂ at that time had increased by 6% compared with the beginning of the century. Because he also found that there was a global warming tendency from the end of the last century to the middle of this century, it caused a lot of repercussions in the world. To this end, Kailin of the Scripps Institution of Oceanography in the United States established an observatory at the altitude of 3400 meters in the Mauna Loa Mountains in Hawaii in 1958, and began a precise observation of the CO ₂ content in the atmosphere. Because Hawaii Island is located in the central North Pacific. Therefore, it can be considered that it is not affected by terrestrial air pollution and the observation results are reliable.

From April 1958 to June 1991, people observed the concentration of CO ₂ in the atmosphere of Mauna Loa. It was found that the content of CO ₂ in the atmosphere was only about 315 ppm in 1958, but reached 355 ppm in 1991. The seriousness of the problem is that currently (1996), only about half of the 5.5 billion tons of fossil fuels burned by humans each year (about 4 tons of CO _{2 are} produced) enter the atmosphere, and the remaining half is mainly absorbed by marine and land plants. Once the CO _{2 in the} ocean reaches saturation, the CO ₂ content in the atmosphere will increase exponentially. In addition, they also found that the CO ₂ content also varies seasonally, with a difference of 6 ppm between winter and summer. This is mainly because the vegetation on the broad continent of the northern hemisphere is the result of winter withering and summer rong, that is, plants absorb a large amount of CO ₂ in summer, so that the concentration of CO _{2 in} the atmosphere is relatively reduced.

According to the CO ₂ concentration measurement of the air in the air bubbles sealed in the ice caps of the Antarctic and Greenland continents, the CO ₂ content in the atmosphere has been relatively stable for a long time, approximately 280 ppm. Only from the middle of the 18th century, before and after the industrial revolution, it started to rise steadily. That is, it took humans 240 years to increase the concentration of CO _{2 in} the atmosphere from 280 ppm to 355 ppm.

Methane is an important greenhouse gas after CO ₂ . Although its concentration in the atmosphere is much less than CO ₂ , its growth rate is much larger. According to the Second Climate Change Assessment Report (the "Report") issued by the United Nations Intergovernmental Panel on Climate Change (IPCC) in 1996, CO ₂ increased by 30% from 240 years between 1750 and 1990, while methane increased by 145% during the same period. . Methane, also called biogas, is produced when organic matter decays under hypoxia. For example, paddy fields, compost and animal manure all produce biogas. Nitrous oxide is also known as laughing gas, because inhaling a certain concentration of this gas can cause facial muscle spasms and look like laughing. It is mainly produced by using chemical fertilizers and burning fossil fuels and organisms. Although the ozone content in the atmosphere is reduced in the stratosphere, it is increased in the troposphere, which will be discussed later. Freon gas is a compound of chlorine, fluorine, and carbon; it does not exist in nature and is entirely manufactured by humans. Because its melting point and boiling point are relatively low, non-combustible, non-explosive, odorless, harmless, and excellent stability, it is widely used in the manufacture of refrigerants, foaming agents and cleaning agents. Although the highest concentrations of Freon 12 and Freon 11 in the earth's atmosphere are very small, the growth rate in the past has been very high, with an annual increase of 5%. Due to its severe damage to the atmospheric ozone layer, its concentration in the atmosphere is expected to gradually decrease from the beginning of the 21st century under the 1987 International Montreal Protocol.

It should be noted that although the concentrations of other greenhouse gases other than CO ₂ in the atmosphere are much smaller than CO ₂ and some are several orders of magnitude smaller, their greenhouse effect is much stronger than that of CO ₂ . Therefore, their contribution to the atmospheric greenhouse effect is only one order of magnitude lower than CO ₂ according to the IPCC's second Report. If their total contribution to the greenhouse effect of the earth's atmosphere is small compared to CO ₂ before 1960, it will be on par with CO ₂ in the near future and even exceed CO ₂ , which cannot be ignored. ^[1]

The greenhouse has two characteristics: 1. The temperature is high in the room, 2. It does not dissipate heat .

The glass greenhouses and vegetable greenhouses we can see in life are typical greenhouses. The use of glass or transparent plastic film to make a greenhouse is to allow sunlight to directly shine into the greenhouse to heat the indoor air, while glass or transparent plastic film can prevent the indoor hot air from being emitted outward, so that the indoor temperature is kept higher than the outside To provide conditions conducive to rapid plant growth. The reason why this effect is called the greenhouse effect is also related to this principle.

Researcher Wang Gengchen , Institute of Atmospheric Physics, Chinese Academy of Sciences : Encourage bold ideas to promote technological innovation

In the 21st century, everyone is advocating a low-carbon life and a low-carbon economy, but it is easier said than done, and it requires the support of science and technology. To reduce the increase in the greenhouse effect, the most important thing is to reduce greenhouse gas emissions. But in general, reducing greenhouse gas emissions is a complex issue that involves all aspects, and it involves all countries in the world. In addition to some scientific and technological problems, reducing greenhouse gas emissions also involves issues of national interest such as the development of the country. At present, China's rapid development has a great demand for energy. Where does energy come from? No doubt it is coal, oil, natural gas, etc. In this century, the use and scope of other clean energy sources such as nuclear power are still very small, and most of them rely on the combustion of fossil fuels.

China has been advocating changes in the industrial structure. From a scientific perspective, this is a very correct policy. Relying on the optimization of the industrial structure to reduce greenhouse gas emissions, especially carbon dioxide emissions, is an effective way to slow the increase of the greenhouse effect. . At the same time, it is suggested that government departments should gradually introduce corresponding incentive and restraint policies, implement low-carbon lifestyles, encourage everyone to go green, and so on. In addition, government departments should also encourage experts and people from all walks of life to actively contribute ideas and suggestions, including encouraging bold ideas such as "establishing an atmospheric shield". With the continuous development of science and technology, people's understanding of the objective world will continue to deepen People always innovate and constantly put forward new ideas to promote the development of science and technology and benefit humanity.

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The rise in global sea levels will directly inundate the coastal lowland areas of the densely populated, industrially and agriculturally developed continent, so the consequences are very serious. At the Second Meeting of the Parties to the United Nations Framework Convention on Climate Change, held in Berlin in November 1995, 44 small island states formed the Alliance of Small Island States to appeal for their right to life.

In addition, the research results also point out that the increase in CO will not only cause global warming, but also cause global atmospheric circulation adjustment and climate zone expansion to the polar regions . In the mid-latitudes, including northern China, precipitation will decrease and coupled with warming, evaporation will increase, so the climate will become arid. The adjustment of the atmospheric circulation may cause climate anomalies and disasters in other parts of the world, in addition to aridity in the mid-latitudes. For example, the intensity of typhoons at low latitudes will increase, and typhoon sources will expand northward. Rising temperatures will also cause and exacerbate the epidemic of infectious diseases. Take malaria as an example. The incidence of malaria in the world has quadrupled in the past five years. About 500 million people worldwide get malaria every year, and more than 2 million people die.

But the greenhouse effect is not all bad. Because the coldest high-latitude regions have the greatest temperature increase, agricultural areas will greatly advance to the poles. Increased CO is also beneficial to plant photosynthesis and directly increases organic matter production . Other papers point out that in China and the world's historical period, the warm period is mostly a period of heavy rainfall and arid regions withdrawing, and so on.

Of course, there are different opinions on the issue of atmospheric greenhouse effect. For example, some scientists believe that the numerical model is still immature and the calculation results are too exaggerated; a 0.3-0.6 ° C increase in centuries is normal climate change and cannot be proven to be caused by the atmospheric greenhouse effect, and so on. Of course this is the opinion of a few people. Nonetheless, there is no fact that the current concentration of CO in the atmosphere and the global temperature are rapidly increasing, and the principle that increasing greenhouse gases will cause global warming. If we wait until the problem has reached a level that humans can clearly perceive, it is often difficult to reverse it, then it is too late. Therefore, great attention must be paid to taking countermeasures to protect the atmospheric environment on which human beings depend .