What is Climate Change
Climate change is a reflection of changes in the state of the atmosphere over long periods of time. Climate change is mainly characterized by changes in the atmosphere over various lengths of time, such as cold and warm, or dry and wet. The alternation of cold and warm or dry and wet makes up different cycles of change. However, these cycles of change are not rigid, and there is often no symmetry between the preceding and following phases of a cycle, and the lengths of the different cycles can vary considerably. Climate change is one such complex and quasi-cyclical change.
There are many different cycles of climate change, and the longer the cycle, the greater the magnitude of change. Modern data can distinguish between cycles of several years of climate change, which is the basic data for studying climate variability. Historical climate history data can reflect tens to hundreds of years of climate change, is the important background of modern climate change. Geological data can reflect climate change over tens of thousands of years, giving a general trend of climate change over this period. Although geological and historical data are ancient, they reflect cycles of climate change that constrain modern climate change.
To know the future of anything in the world, we must first understand its past, and the same is true of climate. It makes sense to study climate change over long periods of time. Climate on a long time scale is the background and basis for analyzing the state of the climate in a shorter period of time. Do not know the past climate change, can not figure out the ins and outs of the current climate, but also can not recognize and evaluate the present climate and predict the future climate.
Currently, we are more concerned about the climate change in the last hundred years. Climate change in the last hundred years can already be expressed in meteorological observations. The most prominent feature of global climate change in the last hundred years is the significant warming of temperature. Almost all analyses of temperature observation records show that the global average temperature has risen by about 0.6°C from the end of the 19th century to the 1990s, with a warming rate of 0.5°C/100 years. Climate warming has caused many of the world's glaciers to melt, or even disappear, the global average glacier material balance is negative; in the last hundred years the global sea level has also risen by an average of 15 centimeters, half of which is estimated to be due to the thermal expansion of seawater, and the other half is due to the melting of snow and ice caused by the beginning of the 1970's, satellite observations show that the area of the Northern Hemisphere snow cover in the spring and summer, from 1987 onwards has declined by 10 percent since 1987. All of this indirect evidence also points to a warming climate in the 20th century. Generally speaking, precipitation has fluctuated roughly everywhere. Temperatures were at their warmest in the 1930s and 1940s, then declined and rose again in the 1980s to a second period of high temperatures.
China's temperature change in the past century is basically similar to the world average, the 30s to 50s is the period of higher temperature, then slightly back down, to the 1980s and rose to a new high value. According to the recent statistics of the China Meteorological Administration, from the 1950s to the 1980s, the warming was more pronounced in the north of China, while the Yangtze River Basin and the southwestern provinces experienced a decline in temperature. The provinces with the most warming are Heilongjiang (0.7 ℃), Inner Mongolia (0.83 ℃), Beijing (0.88 ℃), Hebei (0.84 ℃), Jilin (0.65 ℃), Liaoning (0.64 ℃), Shanxi (0.65 ℃) and other provinces (municipalities); the most cooling is Sichuan (-0.92 ℃), Hubei (-1.09 ℃). Therefore, the temperature change in China in the last hundred years is a clear warming trend in the north, the south is not obvious, and some places even cooling.
Human activities and climate change
Human activities are one of the important members of the global climate system and an important influence on climate change. The impact of human activities on climate change and the link between the two has been a hot topic since the 1970s. Since there has been a warming trend in global temperatures over the last hundred years, and at the same time scientists have noted a marked increase in the concentration of trace gases emitted by humans into the atmosphere, whether there is a causal link between the two, among other things, is a matter of concern for scientists, the public and policy makers in various countries.
During the tens of thousands of years of human development since the emergence of humans on Earth, the vast majority of the time has been spent passively adapting to the environment in which we live and to the corresponding climatic conditions. During this time, humans did not have a large enough impact on the environment and climate, which continued to change under the action of its underlying factors. However, during the 200 years following the world industrial revolution, the earth's population increased dramatically, scientific and technological development and the rapid expansion of the scale of production, human damage to the environment and impact on the climate became more and more significant, and the natural state of the earth's surface and the atmosphere was disrupted. As a result of deforestation and the burning of fossil fuels, the concentration of carbon dioxide in the atmosphere has increased rapidly, leading to an intensification of the greenhouse effect, a process that has been accelerated by the increase in trace gases such as chlorofluorocarbons (CFCs) since the 1960s. At the same time, due to transitional grazing, destruction of primary forests and natural vegetation has changed the physical condition of the surface, the expansion of cities has caused the heat island effect, atmospheric pollution, and the destruction of stratospheric ozone has led to the expansion of the Antarctic ozone hole. All of these have directly or indirectly changed the state of the climate system. At present, the impact of such anthropogenic climate change can reach the same level as the impact of natural factors in climate change on time scales of decades to centuries. Therefore, if not reasonably planned and controlled, the impact of human activities on the climate will increase day by day, will not only destroy the living environment on which human beings depend, but will also jeopardize the sustainable development of society.
Many of the impacts of human activities on the climate and the environment can be postponed for decades or even centuries, and it is difficult to recover them over a long period of time. How to evaluate the impact of human activities on the climate and environment, how to take effective measures to save the advantages and disadvantages, in order to improve the human living environment and climate conditions, to ensure the sustainable development of society, has become a major problem in front of the people, but also in front of the governments of all countries is an urgent need to solve the problem. Our country is in the world's climate vulnerability zone, global warming will certainly have a significant impact on our economic and social development.
The impact of human activities on climate change
The impact of human activities on climate change not only directly affects the climate of warm and dry, but also on the ecological environment, economic and trade to international political relations have a wide range of impacts, and at the same time, changes in the environment and economy will in turn affect the climate change. It can be said that the current global climate change is one of the most complex scientific problems of the earth system ever encountered by mankind. The World Climate Impacts Programme (WCIP), developed under the auspices of the World Meteorological Organization (WMO), proposes ten research directions for climate impacts on human beings: 1. human health and ability to work; 2. housing construction and new housing estates; 3. various types of agriculture; 4. water resources development and management; 5. forestry resources; 6. fisheries and marine resources; 7. energy production and consumption; 8. industrial and commercial activities; 9. traffic and transportation; 10. various public *** services. Among them, the issues of sea level rise and fall due to climate change, the supply of agriculture and food, environmental pollution, ecosystem changes, freshwater resources, and the impacts on human health have received the most attention.
Enhanced greenhouse effect caused by human activities is one of the most important global environmental issues at present. In agricultural production in cold regions, glass (or transparent plastic) houses are often built and crops are planted in them in order to enable crops such as vegetables to grow normally in cold climates. The principle that glass allows short-wave radiation from the sun to pass through is utilized to keep the indoor temperature warm enough during the day. At night, long-wave radiation from the ground is returned to the ground by the glass, which keeps the temperature warm at night. People call such glass houses greenhouses. Some trace gases in the atmosphere, such as water vapor, carbon dioxide, nitrous oxide, methane, etc., can play a similar role as glass, that is, these trace gases in the atmosphere can make the sun's short-wave radiation of certain wavelengths through the ground, thus warming the near-surface layer; but also to make the ground radiated by the long-wave radiation to return to the ground surface, so as to continue to maintain the temperature of the ground. This effect of trace gases in the atmosphere is called the greenhouse effect in the atmosphere, and the trace gases with this greenhouse effect are called "greenhouse gases". According to research, if there were no greenhouse gases in the atmosphere, the average surface temperature would be 33°C lower than it is now. So the presence of these greenhouse gases is very important in creating temperatures on the surface that are suitable for living organisms to live in today.
Since the Industrial Revolution (1750), the concentration of greenhouse gases such as carbon dioxide, methane, and nitrous oxide in the atmosphere has increased by 30%, 145%, and 15%, respectively, as a result of the use of fossil fuels such as coal, oil, and natural gas, as well as the accelerated deforestation and destruction of grasslands (1992), changes that have been attributed primarily to human activities. Many greenhouse gases are present in the atmosphere for long periods of time (e.g., carbon dioxide and methane can be present for decades to centuries) and have a warming effect. As such, they will act for a very long time.
Evidence of global warming in the last 100 years has been manifested in many ways other than temperature, and the observational record of recent decades shows warming features from the surface to the lower and middle troposphere, as well as warming of land soil temperatures and ocean surface SSTs. In addition, soundings show a cooling trend in the upper troposphere and lower stratosphere. In addition, the daily minimum temperatures in most land regions of the world are significantly warmer, and thus the daily difference is significantly reduced. In the past hundred years, global sea level has risen by an average of 20 to 30 centimeters; the global middle and high latitude ice melting, glacier extent to the high latitude contraction, especially in North America and the northern part of Eurasia is the most obvious, the alpine snow line is also obvious contraction.
Climate change is closely related to economic and social development. Global warming is extremely harmful to agricultural production, and in some areas where agricultural production is vulnerable, increased pests and droughts may cause a reduction in food production, thus changing the pattern of food trade. In addition, the impacts of global warming on natural Earth ecosystems are also evident, and the resulting socio-economic consequences will be severe, especially in ecologically fragile areas. The socio-economic development of these areas is strictly dependent on the natural ecosystems, and changes in the ecosystems will have an impact on food, fuel, medicine and building materials, among others, jeopardizing human survival.
The impact of global warming on the water cycle is more pronounced in vulnerable arid and semi-arid areas. For example, China's arid and semi-arid regions have shown a clear trend of drying out over the past 50 years, with some rivers and lakes already drying up. Global warming will likely warm and dry out northern China, resulting in increased drought and water scarcity in the region. Changes in the water cycle, which will alter the way water is used in agriculture, ecosystems and elsewhere, will have serious consequences for, among other things, agriculture and hydroelectric power generation in regions that are already in a state of drought (e.g., Saharan Africa). Some regions that are vulnerable and sensitive to water resources will likely not be able to withstand the stress.
Global warming and the corresponding set of climate changes will also have direct and indirect effects on human health. Studies have shown that with global warming, there will be a significant increase in the number of hot summer days, and an increase in the number of heart disease and high blood pressure patients who commit and die from the disease. Dramatic changes in climate, such as the outbreak of cold waves or the invasion of strong cold air in spring, will have an impact on human health, especially on some sick and frail people. The increase in pests and bacteria caused by global warming is extremely hazardous to human health. For example, high temperatures and humidity may cause mosquitoes and flies to breed, leading to an increase in the incidence of cholera, malaria and yellow fever. High temperatures and drought may lead to an increase in some infectious diseases, which are more harmful in populated areas. Changes in temperature and precipitation can radically alter the distribution of vector-borne and viral diseases, shifting them to higher latitudes and putting more people at risk. Many developing countries are at greater risk because of poorer access to medical equipment and medicines.
The massive melting of snow and ice and thermal expansion of seawater caused by global warming will accelerate sea level rise, altering ocean circulation and marine ecosystems, and inflicting significant socio-economic damage. Global sea level rise will directly jeopardize low islands, low coastal zones, and low-lying areas and countries, many cities are located near the coast, where the population is dense, industrial and agricultural developed. As sea levels rise, seawater could flood farmland, contaminate freshwater supplies, and potentially alter coastlines.
Global warming will have an impact on the human habitat, energy, transportation and industry sectors. The potential response of human settlements to rapidly evolving climate change is fragile, and some of the world's delta regions are vulnerable to sea level rise; this includes the Nile Delta in Egypt, the Ganges Delta in Bangladesh, the Yangtze and Yellow River Deltas in China, the Mekong Delta in the Sino-Indian Peninsula, the Amazon Delta in South America, and the Mississippi Delta in the United States, among others. Rising seas and saltwater intrusion will also cause great economic losses in densely populated industrial zones along the coasts of countries such as Brazil, Argentina and China. Rising seas: drop inundate arable land, forcing mass migration of populations, but also affecting fisheries production.
Adaptation measures to climate change
We only have one Earth, it is our *** with the home, to protect the Earth's environment on which mankind depends for survival, is the world's peoples *** with the same concern. Climate change affects the living environment and socio-economic development of human beings, and human activities in turn affect climate change. Therefore, there is a complex process of interaction and mutual feedback between human activities, climate change and environmental change, involving the intersection of multiple disciplines; the resolution of issues related to climate warming and its impacts requires the ****together participation of multidisciplinary scientists, managers and government officials. Climate and environmental issues without borders, the world's countries only actively participate in the global action to take concerted action, the correct handling of resources, environment and development issues, only through the unremitting efforts of several generations, and ultimately realize the sustainable development of mankind.
Faced with the situation of global warming, our current countermeasures are mainly in the following three areas:
The first is to reduce the current carbon dioxide in the atmosphere. The most practical and feasible in terms of technology is to plant trees extensively and enhance greening; stop deforestation. The photosynthesis of sunlight is used to absorb and fix carbon dioxide in large quantities. There are other ways to absorb carbon dioxide using chemical reactions, but they are technically immature and economically more difficult to implement on a large scale.
The next issue is adaptation, which must be considered in any case. In addition to engineering measures such as the construction of coastal protection dykes to prevent seawater intrusion, the types and varieties of local crops have been systematically and gradually changed to adapt to the changing climate. For example, in the north of Japan, rice was not grown in the past because of the cool summers, or the yields were very low, but thanks to the cultivation of cold-resistant and resilient varieties, even Hokkaido, the northernmost part of the country, is now able to grow rice, and the yields are also very high. Since climate change is a relatively slow process, it is possible to find and implement adaptation measures as long as climate change trends are predicted at an early stage.
Another step is to cut carbon dioxide emissions, and the Framework Convention on Climate Change, which was signed by heads of state at the 1992 World Conference on Environment and Development in Rio de Janeiro, Brazil, calls for developed countries to reduce their carbon dioxide emissions to 1990 levels by the year 2000, and to provide developing countries with financial resources and technology transfers in order to help them reduce their carbon dioxide emissions. emissions. This is because the vast majority of carbon dioxide in the global atmosphere over the past century has been emitted by developed countries. Developing countries must first and foremost lift themselves out of poverty and develop. Developed countries are obliged to do so. However, since the convention is a framework, it is not binding. Moreover, the reduction of carbon dioxide emissions has a direct impact on the economic interests of developed countries, so not only have some developed countries not reduced their emissions, but they are even increasing their emissions, and it is simply not possible to reduce them to the 1990 level in 2000. At the Third Conference of the Parties to the United Nations Framework Convention on Climate Change (Kyoto, Japan), which ended on December 11, 1997, there was a sharp and tense struggle between developing and developed countries. In the end, the developed countries made concessions and the difficult Kyoto Protocol was finally adopted, which stipulates that all developed countries should reduce their emissions of six greenhouse gases (carbon dioxide, nitrous oxide, methane, and three hydrochlorofluorocarbons) by 5.2% in 2011 compared to 1990 levels. That's a far cry from the developing countries' demand for a 15 percent reduction by 2011 and another 20 percent by 2020, but it is, after all, a legally binding international agreement to reduce emissions.
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yniiaigcka88136445642016-12-23 13:32:04