(1) Reduce the amount of solar radiation reaching the ground: A large number of smoke particles discharged into the atmosphere by factories, power stations, automobiles, household heating equipment, etc. make the air very turbid, which blocks the sunlight and reduces the amount of solar radiation reaching the ground. According to observation and statistics, in the days when smoke and dust are not scattered in large industrial cities, the direct sunlight on the ground is reduced by nearly 40% compared with the days without smoke and dust. In cities with serious air pollution, people, animals and plants will be stunted due to lack of sunshine every day.
(2) Increased precipitation and acid rain: Many of the particles emitted by large industrial cities have the function of water vapor condensation nuclei. Therefore, when there are other precipitation conditions in the atmosphere, there will be precipitation weather. In the downwind areas of large industrial cities, there is more precipitation.
③ Acid rain: Sometimes, the rain falling from the sky contains sulfuric acid. This kind of acid rain is the oxidation of sulfur dioxide, a pollutant in the atmosphere, to form sulfuric acid, which falls with the precipitation in nature. Sulfuric acid rain can destroy large areas of forests and crops, corrode and destroy paper products, textiles and leather products, degrade metal antirust coatings and reduce their protective effects, and also corrode and pollute buildings.
(4) Raise the atmospheric temperature: Over large industrial cities, the air temperature near the ground is higher than that in the surrounding suburbs due to a large amount of waste heat discharged into the air. This phenomenon is called "heat island effect" in meteorology.
⑤ Impact on global climate: In recent years, people have gradually noticed the impact of air pollution on global climate change. After research, people think that carbon dioxide plays an important role in various air pollutants that may cause climate change. About 50% of the carbon dioxide released into the atmosphere by countless chimneys and other exhaust pipes on the earth remains in the atmosphere. Carbon dioxide can absorb long-wave radiation on the ground and raise the air temperature near the ground, which is the so-called "greenhouse effect". It is roughly estimated that the near-surface temperature will increase by 0.5 ~ 2℃ for every 25% increase of carbon dioxide content in the atmosphere. If 100% is increased, the near-surface temperature can be increased by 1.5 ~ 6℃. Some experts believe that the carbon dioxide content in the atmosphere will increase at the current rate, which will melt the ice in the North and South poles in a few years, leading to global climate anomalies.
Solution:
The prevention and control of air pollution is a huge systematic project, which requires the joint efforts of individuals, collectives, countries and even countries all over the world. The following measures can be considered:
1, reducing pollutant emissions. Reforming the energy structure, using pollution-free energy's solar energy (such as solar energy, wind energy and hydropower) and low-pollution energy (such as natural gas), pretreating fuel (such as desulfurization before burning coal) and improving combustion technology can reduce pollution emissions. In addition, before pollutants enter the atmosphere, some pollutants in waste gas can be eliminated by dust removal and smoke elimination technology, condensation technology, liquid absorption technology and recycling technology, so as to reduce the amount of pollutants entering the atmosphere.
2, control emissions, make full use of the self-purification ability of the atmosphere. Different meteorological conditions have different atmospheric capacity of pollutants, and the same pollutant discharge will cause different pollutant concentrations. For areas and time periods with strong wind, good ventilation, strong turbulence and strong convection, the atmosphere has strong diffusion and dilution ability and can accept more activities of factories and mines. In the area and time period of inversion, the diffusion and dilution ability of the atmosphere is weak, and it cannot accept more pollutants, otherwise it will cause serious air pollution. Therefore, effective emission control should be carried out in different regions and different time periods.
3, site selection, chimney design, urban and industrial planning should be reasonable, don't exhaust too concentrated, don't cause repeated pollution, leading to serious pollution incidents in some areas.
4. Afforestation: Dense forests can reduce wind speed and reduce a lot of dust carried in the air. The surface of leaves is rough, some have fluff, and some can secrete mucus and oil, so they can absorb a lot of floating dust. Dusty leaves can continue to absorb dust after being washed by rain. Such reciprocating blocking and adsorption of dust can purify the air.
5. Start with yourself. Don't litter, a perfect city is everyone's responsibility.