Thoughts on Climate Warming

This factory emits a lot of waste gas, waste residue and solid waste; Automobile exhaust, human beings hacked.

Global warming refers to the increase of global temperature. In recent 100 years, the global average temperature has experienced two fluctuations of cold-warm-cold-warm, which can always be regarded as an upward trend. Since 1980s, the global temperature has obviously increased. 198 1 ~ 1990, the global average temperature increased by 0.48℃ compared with 100 years ago. The main reason for global warming is that humans have used a lot of fossil fuels (such as coal and oil) and released a lot of greenhouse gases, such as carbon dioxide, in the past century. Because these greenhouse gases have high permeability to short-wave radiation from the sun and high absorption to long-wave radiation reflected from the earth, which is commonly known as the greenhouse effect, scientists have long warned that the sharp rise of sea level will not only bring disasters to many small island countries, but also threaten the coastal areas of other countries. Many creatures, such as polar bears, will become extinct because of the loss of their living environment. Global warming will also lead to an increase in the frequency of high temperature, heat waves, typhoons and heavy precipitation events. Qin Dahe told reporters that several strong typhoons in China last year, the summer drought in Chongqing and the low water level in the Yangtze River were often related to global climate change to some extent. Warming weather has obvious effects on crops. In recent 30 years, the flowering of apple trees in France has been advanced by 10 days, and the sowing date of corn has been advanced by 1 month. Since 65438+February this year, the high temperature in most parts of Jiangsu Province has caused plants to bloom out of season, and osmanthus flowers in some parts of Nanjing have bloomed in severe winter. The National Assessment Report on Climate Change recently issued by the Ministry of Science and Technology, China Meteorological Bureau, China Academy of Sciences and other departments pointed out that climate warming will increase agricultural water demand and regional differences in water supply will also increase. In order to adapt to the change of production conditions, the agricultural cost and investment demand will increase greatly. Some experts believe that the output of main crops in China, such as wheat, rice and corn, will drop by at most 37% in the second half of the 20th century due to the influence of climate warming if technical factors such as improved varieties are not considered. In animal husbandry, the drought trend caused by climate change will increase the potential desertification trend in semi-arid areas, the grassland boundary may expand, the area of alpine grassland will decrease, and the distribution pattern of grassland carrying capacity and carrying capacity will change greatly. Warm weather is changing people's winter activities: in Altay, Xinjiang, the temperature has been obviously high for three consecutive months, which has gradually reduced the snow in ski resorts and reduced the number of tourists by 90%. Warm winter makes all kinds of germs and viruses active, and pests and diseases breed and spread. The probability of mosquitoes, fleas, rats and other harmful animals freezing to death has decreased, and the number of carriers of these infectious diseases has greatly increased, posing a serious threat to human health. Scientists believe that the destruction of forests and other vegetation and increasing greenhouse gas emissions are the main reasons for climate warming. Carbon dioxide emitted by long-term use of fuels such as coal and oil is the most important greenhouse gas. In order to reduce greenhouse gas emissions, China has taken a series of measures in recent years to improve energy efficiency and vigorously develop and utilize clean energy such as nuclear energy, biomass energy, solar energy and wind energy. Over the past 20 years, China has vigorously carried out afforestation, strengthened ecological environment protection and improved forest coverage. The cumulative net absorption of carbon dioxide by forests in China is 3.06 billion tons.

Spherical climate system refers to a highly complex system composed of atmosphere, hydrosphere, cryosphere, lithosphere (land surface) and biosphere, and there are obvious interactions among these parts. Under the impetus and external compulsion of this system (such as volcanic eruption, solar change, atmospheric composition change and land use change caused by human activities), the climate system evolves continuously with time (gradual change and sudden change), with climate change and variability on different time and space scales (monthly, seasonal, interannual, interdecadal and centennial scales). Climate system is one of the main components of the earth system. The earth system also includes human beings and life systems, social and economic aspects and so on. It is a complete and interrelated system with complex metabolism and self-regulation mechanism. Its biological process interacts strongly with physical and chemical processes, forming a complex life support system on the earth. There are many reasons for the change of climate system, which can be summarized into two categories: natural climate fluctuation and the influence of human activities. The former includes solar radiation changes, volcanic eruptions and so on. The latter includes the increase of greenhouse gas concentration in the atmosphere, the change of sulfide aerosol concentration, land cover and land use change caused by human burning fossil fuels and deforestation. Natural factors and climate variability basically all the energy of the climate system comes from the sun, so the change of solar energy output is considered as the radiation force that causes climate change, that is to say, the change of solar radiation is the external cause that causes climate system change. Another reason for the change of solar radiation is the change of earth's orbit. There are three regular changes in the earth's orbit around the sun. First, the eccentricity of elliptical earth orbit (the ratio of major axis to minor axis) changes periodically with 654.38+ million years; Secondly, the inclination angle of the earth's rotation axis relative to the earth's orbit ranges from 21.6 to 24.5, and the period is 4 1 0,000 years; Third, the annual change of the perihelion time closest to the sun, that is, the perihelion time changes in different months of the year, and its cycle is about 23,000 years. Another natural factor affecting climate change is volcanic eruption. After the volcanic eruption, a large number of sulfide aerosols and dust were sprayed into the sky, reaching stratospheric height. They can significantly reflect solar radiation, thus cooling the atmosphere below them. Human activities have intensified the process of climate system change. The global climate change caused by human activities mainly includes human burning fossil fuels, changes in sulfide aerosol concentration, land cover and land use changes (such as the increase of greenhouse gas concentration in the atmosphere caused by deforestation). There are six kinds of greenhouse gases emitted by human activities, namely carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCS), perfluorocarbons (PFCS) and sulfur hexafluoride (SF6), among which carbon dioxide has the greatest impact on climate change. Its warming effect accounts for 63% of all greenhouse gases. Moreover, the retention period in the atmosphere is very long, up to 200 years, and it is fully mixed, so it is the most concerned. The increase of greenhouse gases mainly affects or warms the global climate through the greenhouse effect. The average temperature of the earth's surface depends entirely on the radiation balance, and greenhouse gases can absorb part of the thermal radiation from the surface, thus causing the global atmosphere to warm. In other words, these greenhouse gases are like a quilt covering the surface, and the surface of the quilt is colder than the inside and outside, so that the surface radiation will not be emitted into space unimpeded; So the surface is warmer than without these greenhouse gases. Since 1750, due to the influence of human activities, the concentrations of global atmospheric greenhouse gases such as carbon dioxide, methane and nitrous oxide have increased significantly. In 2005, the global atmospheric CO2 concentration was 379ppm, which has far exceeded the natural variation concentration range recorded by ice cores since 650,000 years before industrialization, and is the highest value since 650,000 years. According to various research results, it is confirmed that the increase of global average temperature observed in the past 50 years is probably caused by the increase of human greenhouse gas concentration.