Isn’t it because of the greenhouse effect that global temperatures are rising? Then why has it snowed so frequently in Shanghai in recent days?

The greenhouse effect (Efecto Invernadero in Spanish) refers to the insulation effect formed by the lack of heat exchange with the outside world in a closed space that transmits sunlight. That is, the short-wave radiation of the sun can penetrate into the ground through the atmosphere, and the ground warms. The long and short radiation released later is absorbed by carbon dioxide and other substances in the atmosphere, resulting in an atmospheric warming effect. The carbon dioxide in the atmosphere acts like a thick layer of glass, turning the earth into a big greenhouse. It is estimated that without the atmosphere, the average surface temperature would drop to -23°C, while the actual average surface temperature is 15°C. This means that the greenhouse effect increases the surface temperature by 38°C.

The greenhouse effect, also known as the "green house effect", is the common name for the atmospheric insulation effect. The increase in the concentration of carbon dioxide in the atmosphere prevents the earth's heat from dissipating, causing a perceptible increase in the earth's temperature. This is the famous "greenhouse effect." Gases that destroy the normal relationship between infrared radiation between the atmosphere and the ground and absorb infrared radiation released by the earth, like a "greenhouse", cause the earth's temperature to rise are called "greenhouse gases". Carbon dioxide is the most abundant greenhouse gas, accounting for approximately 0.03% of the total volume of the atmosphere. Many other trace gases also produce greenhouse effects, some of which have stronger greenhouse effects than carbon dioxide.

The atmosphere can make the short-wave radiation of the sun reach the ground, but the long-wave thermal radiation emitted by the surface is absorbed by the atmosphere, which increases the temperature of the surface and lower atmosphere, because it functions like a greenhouse for cultivating crops. , hence the name greenhouse effect. If this effect did not exist in the atmosphere, surface temperatures would drop by about 330C or more. On the contrary, if the greenhouse effect continues to strengthen, global temperatures will continue to rise year by year. Since the Industrial Revolution, the amount of heat-trapping greenhouse gases such as carbon dioxide emitted by humans into the atmosphere has increased year by year, and the greenhouse effect of the atmosphere has also increased. This has caused a series of serious problems such as global warming, which has caused concern in countries around the world. of attention.

In addition to carbon dioxide, gases that play an important role in producing the greenhouse effect include methane, ozone, chlorofluorocarbons, and water vapor. With the rapid increase in population and the rapid development of industry, the amount of carbon dioxide emitted into the atmosphere has increased accordingly; and because forests have been cut down in large numbers, the carbon dioxide in the atmosphere that should be absorbed by the forests has not been absorbed. As carbon dioxide gradually increases, the greenhouse effect continues to increase. . According to analysis, over the past two hundred years, carbon dioxide concentration has increased by 25%, and the earth's average temperature has increased by 0.5°C. It is estimated that by the middle of the next century, the average temperature of the earth's surface will rise by 1.5-4.5℃, with the temperature rising even more in mid- and high-latitude regions.

The air contains carbon dioxide, and the levels have remained essentially constant over long periods of time. This is because the carbon dioxide in the atmosphere is always in a dynamic equilibrium state of "growing and consuming". 80% of the carbon dioxide in the atmosphere comes from the respiration of humans, animals and plants, and 20% comes from the burning of fuels. 75% of the carbon dioxide dispersed in the atmosphere is absorbed and dissolved in water by ground water and aerial precipitation in oceans, lakes, rivers, etc. There is also 5% of carbon dioxide, which is converted into organic matter and stored through plant photosynthesis. This is why carbon dioxide has remained constant at 0.03% (volume fraction) of air for many years.

However, in recent decades, due to the rapid increase in population and rapid industrial development, the carbon dioxide produced by breathing and the carbon dioxide produced by the combustion of coal, oil, and natural gas have far exceeded past levels. On the other hand, due to the indiscriminate deforestation, a large amount of farmland has been built into cities and factories, destroying vegetation and reducing the conditions for converting carbon dioxide into organic matter. In addition, surface waters are gradually shrinking and precipitation is greatly reduced, which reduces the conditions for absorbing dissolved carbon dioxide and destroys the dynamic balance of carbon dioxide generation and transformation, causing the carbon dioxide content in the atmosphere to increase year by year. The increase in carbon dioxide content in the air has caused changes in the earth's temperature.

Nitrogen and oxygen have the highest proportions in the air, and they can both transmit visible light and infrared radiation. But carbon dioxide cannot pass through infrared radiation. Therefore, carbon dioxide can prevent surface heat from radiating into space and has the function of regulating the earth's temperature. Without carbon dioxide, the Earth's average annual temperature would be 20°C lower than today. However, if the carbon dioxide content is too high, the earth will seem to be in a pot, and the temperature will gradually rise, forming a "greenhouse effect." In addition to carbon dioxide, there are other gases that form the greenhouse effect. Among them, carbon dioxide accounts for about 75%, chlorofluoroalkane accounts for about 15% to 20%, and there are more than 30 kinds of methane, nitric oxide, etc.

If the carbon dioxide content doubles compared to today, global temperatures will rise by 3 to 5 degrees Celsius, and the polar regions may rise by 10 degrees Celsius, and the climate will become significantly warmer. Rising temperatures will lead to increased rainfall in some areas, droughts in some areas, stronger and more frequent hurricanes, and intensified natural disasters. What is even more worrying is that as temperatures rise, glaciers in the polar regions will melt and sea levels will rise. Many coastal cities, islands or low-lying areas will face the threat of rising seawater, or even be engulfed by seawater. 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 1.5 million people died from starvation.

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

Scientists predict that every time carbon dioxide in the atmosphere doubles in the future, the global average temperature will rise by 1.5 to 4.5 degrees Celsius, and the temperature rise in the polar regions will be about three times higher than the average. Therefore, rising temperatures will inevitably partially melt the polar ice, causing sea levels to rise. The impact of sea level rise on human society is very serious. If the sea level rises by 1 m, the directly affected land will be about 5×106 km2, the population will be about 1 billion, and the cultivated land will account for about 1/3 of the world's total cultivated land. If extremely large storm surges and salt water intrusion are taken into account, coastal areas below 5 m above sea level will be affected. The population and food production in these areas account for about 1/2 of the world's population. Some coastal cities may have to move inland, and most coastal plains will become salty or swampy, making them unsuitable for food production. At the same time, it will also cause disasters to the middle and lower reaches of the river. When seawater intrudes, it will cause the water level of the river to rise, accelerate sedimentation, intensify the threat of floods, and drastically worsen the environment in the lower reaches of the river. The greenhouse effect and global warming have aroused widespread concern around the world. Currently, the formulation of an international climate change convention is being promoted, and reducing carbon dioxide emissions has become a general trend.

Scientists predict that if I start cutting down trees in a controlled manner now, global warming will be reduced by 5% by 2050.

Features

The greenhouse has two characteristics: the temperature is higher than the outdoor temperature and it does not dissipate heat. The glass flower rooms and vegetable greenhouses we can see in life are typical greenhouses. Using glass or transparent plastic film to make a greenhouse allows sunlight to directly shine into the greenhouse and heat the indoor air. The glass or transparent plastic film prevents the indoor hot air from radiating outward, keeping the indoor temperature higher than the outside world. state to provide conditions conducive to rapid plant growth.

Consequences

1) Increase in pests and diseases on the earth;

2) Rising sea levels;

3) Abnormal climate and ocean storms Increase;

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

Scientists predict: If the increase in the earth's surface temperature continues at the current rate, the global temperature will rise by 2-4 degrees Celsius by 2050, and the icebergs in the Arctic and Antarctic will melt significantly, causing sea levels to rise significantly. Some island countries and coastal cities will be submerged in water, including several famous international cities: New York, Shanghai, Tokyo and Sydney.

The greenhouse effect can make prehistoric deadly viruses threaten humans

American scientists recently warned that as rising global temperatures melt the Arctic ice, deadly prehistoric viruses that have been frozen for hundreds of thousands of years It may reappear, causing the world to fall into an epidemic panic and seriously threatening human life.

Scientists from Syracuse University in New York pointed out in the latest issue of "Scientist Magazine" that they had previously discovered a plant virus TOMV. Since the virus spreads widely in the atmosphere, it is inferred that it is in the Arctic ice There are traces of it too. So researchers extracted four ice blocks from Greenland with ages ranging from 500 to 140,000 years old, and found the TOMV virus in the ice. Researchers say the virus is surrounded by strong proteins on its surface, allowing it to survive adversity.

This new discovery leads researchers to believe that a series of epidemic viruses such as influenza, polio and smallpox may be hidden deep in the ice. At present, humans have no resistance to these original viruses. When When global temperatures rise and the ice melts, these viruses that have been buried in the ice for thousands of years or more may be resurrected and form epidemics. Scientists say that while they don't know the survival prospects of these viruses, or their chances of adapting to terrestrial environments again, they certainly can't rule out the possibility of a comeback.

Origin

The greenhouse effect is mainly caused by the excessive burning of coal, oil and natural gas in modern industrial society, which emits a large amount of tail gas. After burning these fuels, a large amount of carbon dioxide gas is released into the atmosphere.

Carbon dioxide gas has the functions of absorbing heat and insulating heat. The result of its increase in the atmosphere is the formation of an invisible glass cover, which prevents the heat radiated from the sun to the earth from radiating to outer space. As a result, the earth's surface heats up. Therefore, carbon dioxide is also called a greenhouse gas.

Human activities and nature also emit other greenhouse gases, which are: chlorofluorocarbons (CFC), methane, low-altitude ozone, and nitrogen oxide gases. The earth can absorb a large amount of carbon dioxide in the ocean. Plankton and terrestrial forests, especially tropical rainforests

In order to reduce excessive carbon dioxide in the atmosphere, on the one hand, people need to save electricity as much as possible (because coal is used to generate electricity) and drive less cars. On the one hand, we should protect forests and oceans, such as not deforestation and pollution of the oceans to protect the survival of plankton.

We can also protect green plants by planting trees, reducing the use of disposable wooden chopsticks, saving paper (wood used for papermaking), not trampling on lawns, etc., so that they can absorb more carbon dioxide to help slow down the greenhouse effect.

Since 1975, the average temperature of the earth's surface has increased by 0.9 degrees Fahrenheit, and global warming caused by the greenhouse effect has become a focus of academic attention. The accepted theory is that carbon dioxide produced by burning coal, oil, natural gas, etc. is the main culprit of global warming. However, after decades of observation and research, Dr. James Hansen from the Goddard Institute for Space Studies in the United States put forward a new view. The main greenhouse gas is not carbon dioxide, but carbon dust and other substances.

Carbon dust is a solid particulate matter, mainly due to the high carbon utilization rate when burning high-carbon fuels such as coal and diesel. It not only wastes resources, but also causes environmental pollution. The accumulation of numerous carbon particles in the troposphere 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 atmospheric reverse radiation generated by clouds. The thicker the clouds, the less heat can be diffused outwards, and the earth will become hotter.

Dr. Hansen looked at the changes in the content of various greenhouse gases. They have compiled records and found that between 1950 and 1970, the level of carbon dioxide nearly tripled, while from the 1970s to the late 1990s, the level of carbon dioxide decreased. It is difficult to explain the deterioration with the current popular theory. The phenomenon of global warming.

Dr. Hansen believes that in addition to carbon dust, there are also some gaseous substances that can cause the greenhouse effect, such as ozone in the troposphere (normal ozone should be concentrated in the stratosphere) , methane, and extremely toxic chlorofluorocarbons, but it is relatively difficult to control these pollution sources. Fortunately, the content of non-carbon dioxide greenhouse gases has declined to a certain extent in recent decades, such as methane and troposphere. The ozone content can also decline year by year, so in another 50 years, the change in the average temperature of the earth's surface will be close to zero.

Carbon dust is not inevitable. As the quality of internal combustion engines continues to improve, Even with the advent of vehicles that do not use internal combustion engines, the remaining carbon particles can be reduced. If Dr. Hansen's theory can be established, it will bring new hope for cooling the earth. I hope the earth will cool down soon.

The CO2 content in the atmosphere before the industrial revolution was 280 ppm. If the current growth rate is used, the CO2 content will increase to 550 ppm by 2100, which is almost doubled. Many meteorologists around the world are working hard to study. How much will the global average temperature increase by 2100 after the CO2 content doubles?

The specific method currently used is to design a numerical model for calculation based on the laws of atmospheric movement and physical state changes. , because people’s understanding of the changing laws of atmospheric motion is not perfect enough, and different simplified calculation methods are adopted, the calculation results of each model often vary greatly. To this end, the American Academy of Sciences organized an evaluation committee in the 1980s to conduct research and comprehensive evaluation of the results of these models, and finally concluded that after doubling CO2, the global average temperature will rise by 3°C ± 1.5°C, or 1.5°C-4.5°C. This is the number used in the first "Report" of the United Nations IPCC, the most authoritative organization on this issue.

Climate models have improved significantly in recent years by taking into account the role of aerosols (tiny particles suspended in the air) in the atmosphere. Because when burning fossil fuels releases CO2, it also releases huge amounts of sulfide and other aerosols. This kind of aerosol will block part of the sunlight from reaching the ground, thus lowering the ground temperature and playing a cooling effect. Its value is estimated by IPCC to be -0.5 W/m2. That is equivalent to 1/3 of the warming effect of CO2 (1.56 W/m2), which is slightly larger than the warming effect of methane (+0.47 W/m2). Mainly based on this improvement, in the second "Report" published by the IPCC in 1996, the warming value of the global average temperature after the doubling of CO2 in 2100 was revised 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, only about 50%-90% of this warming value will be achieved by 2100.

However, the model calculation results also show that the global average temperature increase of 1.0℃-3.5℃ is not evenly distributed around the world. Instead, the equatorial and tropical regions are not warming or are barely warming, and the warming is mainly concentrated in high latitudes. In some areas, the number can reach 6℃-8℃ or even greater. 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 zones on high-latitude continents in the Northern Hemisphere will also melt or thin, causing swamping in large areas. In addition, the expansion of seawater volume as the ocean warms will also cause sea level rise. The IPCC’s first assessment report predicted that sea level would rise by 70-140 centimeters (corresponding to a warming of 1.5°C to 4.5°C). The second assessment report predicted a decrease of about 25% from the first assessment (corresponding to a warming of 1.0°C to 3.5°C). ℃), the most likely value is 50 cm.

The IPCC's second assessment report also pointed out that in the past century since the end of the 19th century, as the global average temperature has increased by 0.3°C-0.6°C, global sea levels have also risen by 10-25 cm.

The rise in global sea levels will directly submerge the coastal lowland areas of the continent with dense population and developed industry and agriculture, so the consequences will be very serious. At the Second Conference of the Parties to the United Nations Framework Convention on Climate Change held in Berlin in November 1995, 44 small island countries formed the Alliance of Small Island States to appeal for their right to exist.

In addition, the research results also pointed out that the increase in CO2 will not only cause global warming, but will also cause the adjustment of global atmospheric circulation and the expansion of climate zones to the poles. Precipitation in mid-latitude areas, including northern my country, will decrease, and rising temperatures will increase evaporation, so the climate will become arid. Adjustments in atmospheric circulation, in addition to mid-latitude aridity, 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 temperatures will also cause and intensify the spread of infectious diseases. Take malaria as an example. The incidence of malaria in the world has quadrupled in the past five years. Now about 500 million people around the world get malaria every year, and more than 2 million of them die.

However, the greenhouse effect is not all bad. Because the coldest high latitudes are experiencing the greatest warming, agricultural areas will advance significantly toward the poles. Increased CO2 is also beneficial to plant photosynthesis and directly increases organic matter production. There are also papers that point out that in the historical periods of our country and the world, warm periods are mostly prosperous periods with more precipitation and arid areas retreating, etc.

Of course, there are also different opinions on the issue of atmospheric greenhouse effect. For example, in the past, some scientists believed that the current numerical models were immature and the calculation results were too exaggerated; a century-old increase of 0.3°C to 0.6°C was considered normal climate change and could not be proven to be caused by the atmospheric greenhouse effect, etc. Of course this is a minority opinion.

Nevertheless, there is no debate about the fact that the concentration of CO2 in the atmosphere and global temperature are increasing rapidly, and that the increase in greenhouse gases will cause global warming. If we wait until the problem develops to a level that humans can clearly perceive, it is often difficult to reverse it, and then 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 for survival.

Countermeasures

Although we have not been able to come up with effective solutions so far, the next best thing is to at least try our best to curb the growth of emissions, and we cannot leave it to fate.

First of all, 2050 is tentatively set as the target. If the current situation continues and combined with the impact of various greenhouse gases, it is expected that the average temperature of the earth will increase by more than two degrees. Once the temperature rises so much, the earth's climate will cause major changes.

Therefore, the best solution for now is to do everything we can to take countermeasures and try to suppress the upward trend. At present, international public opinion is also constantly calling in this direction, and research institutions in various countries have also proposed various specific countermeasures.

Unfortunately, after carefully examining various options, no single countermeasure has been found to be sufficient to solve the problem on its own. Therefore, it is necessary to explore all possibilities and fully consider the effectiveness of these countermeasures.

1. Comprehensive ban on chlorofluorocarbons

In fact, the world is promoting efforts in this direction, so this case is the most likely to be realized. If this case can be realized, it is estimated that it will have an inhibitory effect of about 3% on global warming until 2050.

2. Countermeasures to protect forests

Today, the global forests that rely on tropical rainforests for survival are being rapidly and continuously destroyed by humans. The effective response is to stop this uncontrolled destruction of forests as soon as possible, and on the other hand, implement large-scale afforestation work and strive to promote forest regeneration. The amount of carbon dioxide currently released into the atmosphere due to forest destruction is estimated to be about 1 to 2 gt. of carbon per year. If countries seriously promote deforestation control and forest regeneration plans, by 2050, the entire biosphere may absorb carbon dioxide equivalent to 0.7gt. of carbon per year. As a result, the greenhouse effect can be reduced by about 7%.

3. Improvement of automobile fuel consumption

Japanese automobiles have achieved technological improvements in this regard, greatly improving their fuel consumption in the past. However, in places such as the United States, perhaps due to abundant oil reserves, there have been no obvious signs of improvement in terms of fuel-saving design, and excessive fuel consumption is still maintained. Therefore, there is ample room for improvement in fuel design of cars produced in the region. The reduction in fossil fuel consumption resulting from this effort is estimated to reduce the greenhouse effect by about 5% by 2050.

4. Improve the energy use efficiency of various other occasions

It is to improve the energy use efficiency of various other occasions. Today's human life uses a lot of energy everywhere, especially in heating and cooling equipment in homes and offices. Therefore, there is still room for significant improvement in improving energy efficiency, which is expected to have an inhibitory effect of about 8% on global warming by 2050.

5. Tax the production and consumption of fossil fuels in proportion

This may prompt manufacturers and consumers to be vigilant when using energy and avoid making What a waste. Its tax revenue can be used for forest protection and the development of alternative energy sources.

When any fossil fuel is burned, carbon dioxide is emitted. However, their emissions vary depending on the type of fossil fuel. Since the main component of natural gas is methane, its carbon dioxide emissions are lower than those of coal and oil. To generate one kilocalorie of heat, coal must emit carbon dioxide equivalent to 0.098 grams of carbon; for oil, it is 0.085 grams; if it is replaced by natural gas, it only needs to emit 0.056 grams.

Therefore, some people propose to impose heavier taxes on natural gas, petroleum, and coal in that order. For example, in terms of production, coal, which emits relatively high carbon dioxide emissions, will be taxed at US$0.5 per billion joules in terms of energy, while natural gas will only be taxed at US$0.23. In other words, fossil fuels with higher carbon dioxide emissions will be taxed more heavily. As for consumption, the same applies. The tax rate is set at 23% for coal and 13% for natural gas.

Of course, at this stage, it is just an idea. But if it is really implemented, it is expected to provide about a 5% suppression effect on global warming by 2050.

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

Because natural gas emits less carbon dioxide. Recently, Japanese cities have generally switched to natural gas instead of liquefied gas, and this case hopes to further promote this movement. However, its effect in inhibiting warming is not very large, only about 1% at most.

7. Exhaust restrictions of automobiles and motorcycles

Since the exhaust of automobiles and motorcycles contains a large amount of nitrogen oxides and carbon monoxide, it is hoped to reduce its emissions. Although this approach cannot achieve the goal of directly reducing carbon dioxide, it can have the effect of suppressing other greenhouse gases such as ozone and methane. It is expected to contribute about 2% to the restraining effect on warming until 2050.

8. Encourage the use of solar energy

For example, promote the so-called "Sunshine Plan". Efforts in this area can relatively reduce the use of fossil fuels, and therefore have a direct effect on reducing the greenhouse effect. However, even if this plan is actively promoted, it will only have an inhibitory effect of about 4% on warming until 2050. The effect seems to be less than what people expected.

9. Develop alternative energy sources

Use biomass energy as a new clean energy source. That is to say, organic matter produced by plants through photosynthesis is used as fuel to replace existing highly polluting energy sources such as petroleum.

Burning bioenergy will also produce carbon dioxide. This is of course the same as fossil fuels. However, bioenergy continuously absorbs carbon dioxide from nature as raw material, so it can become a renewable energy source that repeats cycles to achieve suppression. The effect of increasing carbon dioxide concentration.

Reference: Baidu