Global warming, since the industrial revolution, due to the increase of greenhouse gases, the temperature of the earth's lower atmosphere has gradually increased. The atmospheric temperature near the earth's surface is warmed by a natural process called greenhouse effect. Visible short-wave light shines from the sun to the earth and passes through a layer of hot gas or greenhouse gas mainly composed of water vapor, carbon dioxide, methane, nitrous oxide and ozone. Infrared radiation is reflected from the pla surface to space, but it is not easy to pass through the thermal insulation layer. A part of pla is trapped and reflected downwards, which keeps PLA at an average temperature suitable for life, about 60 F (16 C). Since the industrial revolution, the development of industry, agriculture and transportation has produced a large number of natural greenhouse gases, which, together with chlorofluorocarbons and other gases, have expanded the thermal carpet. It is generally believed that the increase in the amount of greenhouse gases absorbs more heat and raises the global temperature, making a process beneficial to life potentially destructive and harmful. In the past century, the atmospheric temperature rose by 1. 1 Fahrenheit (0.6 degrees Celsius) and the sea level rose by several inches. Some expected long-term results of global warming include melting polar ice, leading to sea level rise and coastal floods; The supply of drinking water that depends on the melting of snow is interrupted; The profound changes brought by climate change to agriculture; With the disappearance of niche, species become extinct; More frequent tropical storms; And an increase in the incidence of tropical diseases. Factors that may lead to global warming include the burning of coal and petroleum products (sources of carbon dioxide, methane, nitrous oxide and ozone); Deforestation has increased the content of carbon dioxide in the atmosphere; Methane gas released from animal excrement; And increasing the number of cattle, which leads to deforestation, methane production and the use of fossil fuels. Many debates around global warming focus on the accuracy of scientific prediction of future warming. In order to predict the global climate trend, climatologists have accumulated a large number of historical databases and used them to create computerized models to simulate the global climate. The validity of these models has always been a controversial topic. Skeptics say that the climate is too complex to model accurately, and there are too many unknowns. Some people also question whether the observed climate change only represents the normal fluctuation of global temperature. Nevertheless, for some time, it has been generally believed that at least some of the observed warming is the result of human activities, and this problem needs to be solved. 1992, at the United Nations Conference on Environment and Development, more than 150 countries signed a binding declaration to slow down global warming. However, in 1994, the United Nations scientific advisory panel, the Intergovernmental Panel on Climate Change, concluded that in order to avoid global warming, it is necessary to reduce emissions beyond those envisaged in the treaty. In the second year, the advisory group predicted that if no action is taken to reduce the production of greenhouse gases, the global temperature will rise from 1.44 to 6.3 degrees Fahrenheit (0.8-3.5 degrees Celsius) by 2 100, and even if action is taken, the temperature will rise from 1 to 3.6 degrees Fahrenheit (0.5-2). 1997 The United Nations Climate Change Conference held in Kyoto, Japan reached an international agreement to combat global warming, which called on industrialized countries to reduce greenhouse gas emissions. However, not all industrialized countries immediately signed or ratified the agreement. 200 1 Bush administration renounces Kyoto Protocol; Because the United States produces a quarter of the world's greenhouse gases, this is considered to be a serious blow to efforts to slow down global warming. Despite the action taken by the United States, most other countries reached an agreement on the necessary details of transforming the agreement into a binding international treaty later that year (in Bonn, Germany and Marrakech, Morocco), which came into force in 2005 after being ratified by 125 countries. Increasing vehicle mileage, reforestation projects, building energy conservation and state support for public transportation are all relatively simple adjustments that can significantly reduce greenhouse gas emissions in the United States. More active adjustments include phasing out the use of fossil fuels worldwide, eliminating chlorofluorocarbons, and slowing down deforestation by adjusting the economic structure of developing countries. In 2002, the Bush administration proposed several voluntary measures to slow down rather than reduce greenhouse gas emissions.