There are two main reasons for climate change. One is the natural change law of the earth system, that is, the periodic change of cold, warm, dry and wet, from seasonal scale to hundreds of thousands of years or even longer; The other is climate change caused by human activities. The climate change in recent 50 years is mainly caused by human activities, which have a great influence on the climate. It can change the inherent laws of nature and pose a threat to our human survival and development, thus attracting the attention of scientists, politicians and the public. Therefore, global warming and climate change have become the main concerns of governments, the public and the scientific and technological circles. However, this problem is quite complicated. If the problems of climate change and global warming are simply attributed to greenhouse gas emissions, then our understanding is too simplistic. I believe that climate change is not only a scientific issue, but also a technical issue, as well as economic, social, political, diplomatic and even national security issues, which are very complicated.
Human activities cause climate change, mainly by burning fossil fuels to emit greenhouse gases and changing land use. There are six kinds of greenhouse gases emitted by human activities, including carbon dioxide, methane, nitrous oxide and other hydrofluorocarbons. Among them, the warming effect of carbon dioxide accounts for about 60% of the total greenhouse gas effect. Now the concentration of carbon dioxide in the atmosphere is increasing, at least dating back to the Western Industrial Revolution. In the past twenty years, China has released a lot of carbon dioxide.
Once carbon dioxide is discharged into the atmosphere, its life span is 50-200 years. The current global warming is caused by the cumulative emission of carbon dioxide. According to statistics, from 1750 to 1950, the carbon dioxide emitted by developed countries accounted for 95% of the world total; From 65438 to 0950-2002, the carbon dioxide emissions of developed countries accounted for 77% of the global cumulative emissions. Developed countries have released a lot of greenhouse gases in the process of industrialization for more than 200 years, and they have an unshirkable responsibility for climate change and should bear the main obligations; Developing countries have less historical emissions and low per capita emissions at present, which belong to survival emissions. Their primary task is still to develop the economy, eliminate poverty and improve their ability to cope with climate change. In response to climate change, the development rights and space of developing countries should be fully considered.
With the deepening of people's understanding of climate change, the World Meteorological Organization and the United Nations Environment Programme organized the establishment of the Intergovernmental Panel on Climate Change (IPCC), which has carried out four scientific assessments of climate change since the 1990s. The IPCC's Fourth Assessment Report, officially released in February this year, has a clearer understanding of the causes of climate change. The fourth assessment report pointed out that it is an indisputable fact that the climate system is warming. The evidence of climate warming comes not only from the atmosphere, that is, the global surface temperature has increased by 0.74℃ in the last hundred years, but also from the hydrosphere and cryosphere, the sea level is also rising, and the snow area in the northern hemisphere is decreasing sharply.
Climate and environmental changes in China.
2006 was the warmest year in China since 195 1. Since the winter of 1986- 1987, China has experienced 2 1 consecutive "warm winters". Like the global average, the temperature in China has been rising since 100, with an average increase of 0.5℃-0.8℃.
Let's look at the precipitation changes in China. Generally speaking, the precipitation in the west and south of China is increasing, while the precipitation in most parts of North China and Northeast China is decreasing. Most parts of North China will decrease by 20-40mm every 10 year, and South China and Southwest China will increase by 20-60mm every 10 year. The drought trend is very obvious in parts of North China, central and eastern Inner Mongolia and Northeast China. In the summer of 2006, Chongqing suffered the worst drought in a century, and Sichuan suffered the worst drought since 195 1. From June 1 to August 2 1, the average precipitation in Chongqing and Sichuan is 345.9 mm, which is the least since June 195 1. In addition to temperature and precipitation, the frequency of strong typhoons has also increased. In the 1970s, the frequency of strong typhoons landing in China increased from less than 20% in the early 1970s to about 35% in the early 20th century, almost doubling. On August 10, 2006, the super typhoon "Sang Mei" landed in Cangnan, Zhejiang. When landing, the maximum wind force near the center reaches17 (60m/s), once in a hundred years. This is the strongest typhoon that landed in Chinese mainland since the founding of the People's Republic of China, and it is stronger than the maximum wind force in the center when Hurricane Katrina landed in 2005.
Since the beginning of this century, some significant changes have taken place in sandstorms in northern China. Sandstorms 18 times occurred in the spring of 2006, including 5 strong sandstorms, the most since 5438+0 in 2006. There are fewer sandstorms in the north this spring. I want to tell you in particular how to treat sandstorms scientifically. I think sandstorm is basically a natural phenomenon. China is a country affected by monsoon climate. What is the monsoon effect? Generally speaking, the prevailing wind blows from the ocean to the mainland in summer, bringing rich water vapor, heat and precipitation to the mainland. In winter, cold and dry air is pushed from the north and Siberia to the south, and strong winds roll up dust and bring sandstorms. This history is at least120,000 years. About 78 million years ago, the Qinghai-Tibet Plateau rose rapidly and the northwest of China became an arid area. Open the map and see that 30 degrees north and south latitude are deserts, but this place in the south of the Yangtze River has become fertile soil because of the monsoon. On the other hand, the winter cold air (winter wind) came, which brought a lot of dust and heavy particles to the Loess Plateau, covering an area of nearly 700,000-800,000 square kilometers, with a thickness of 1.000 meters and a time span of1.20,000 years. Fine-grained materials are continuously transported to the ocean, and extremely fine materials reach 5000, 6000 and 8000 meters high, forming cloud condensation nuclei over the Pacific Ocean. The minerals in it sink into the ocean and become bait for plankton. After the food chain process of plankton, small fish, shrimp and big fish, it finally becomes delicious on our table. This natural biogeochemical cycle, neither you nor I can change this scientific fact. Therefore, the formation of sandstorms stems from natural processes, and it is impossible to eradicate sandstorms. Humans can only improve the environment and optimize the environment locally within their power. Suitable forest is forest, suitable grass is grass, and suitable sand is sand. This is my opinion. Therefore, on the one hand, we should optimize the environment, on the other hand, we should understand the causes of sandstorms and the inherent laws of nature, and never try to be brave, otherwise we will be punished by nature.
In the past half century, the temperature in Guangdong Province has been on the rise. In the last ten years, like the whole country, the temperature rise is also obvious. In recent 50 years, the average surface temperature in Guangdong has increased by 0.2℃ every 10 year, which is higher than the national average. In addition, high temperature days, that is, the days when the highest temperature exceeds 35℃, have increased. Especially since 1998, the number of high temperature days is obviously more than before, especially in the 1960s and 1970s. In addition, the haze weather has also increased, and the sunshine hours have decreased. Haze is a natural phenomenon, which is formed by extremely fine water vapor in the air and industrial dust, and the atmospheric transparency is low. This situation exists not only in Guangdong, but also in the Pearl River Delta, Yangtze River Delta, Tianjin, Beijing, Tangshan and other urban agglomerations.
In addition, the variability of precipitation increases, and the frequency of heavy precipitation also increases. /kloc-from June 0/8 to June 25, 2005, Guangdong Province was hit by a once-in-a-century torrential rain, and the cumulative rainfall in Longmen County of Huizhou City was 1300mm. From late May to mid-June, 2006, the precipitation ("Dragon Boat Water") in Guangdong reached 572 mm, the heaviest year since 1960.
The number of tropical cyclones that landed in Guangdong showed a decreasing trend, and no more than two tropical cyclones landed in Guangdong in recent seven years 1 1 year.
It can be said that urbanization has intensified the temperature rise in Guangdong, and the temperature in the city center is higher than that in the suburbs, which is the so-called urban heat island effect. The annual average temperature growth rate of Pearl River Delta urban agglomeration is several times higher than that of northern Guangdong.
Countermeasures and suggestions to deal with climate change
Like the whole world, China's climate and environment have undergone and will continue to undergo major changes. Climate warming goes far beyond the general climate and environmental problems, and has brought a very serious realistic threat to China's economic and social development, and this threat will continue and intensify. The party and the government attach great importance to Qi.
China's national plan to deal with climate change puts forward six principles to deal with climate change: to deal with climate change under the framework of sustainable development; Pay equal attention to climate change mitigation and adaptation; Organically combine climate change policy with other related policies; Relying on scientific and technological progress and innovation; Follow the principle of "common but differentiated responsibilities"; Actively participate and cooperate extensively.
Greenhouse gas emission reduction is a hot topic that people are talking about at present, especially for governments at all levels. I think this matter should be viewed comprehensively. Climate change involves all aspects, and emission reduction is only one of the important links, but it does not mean all links. It cannot be said that reducing emissions can solve all the problems of climate change. Because the life of greenhouse gases in the atmosphere is very long, even if very strict emission reduction measures are implemented, the greenhouse gases in the atmosphere will continue to increase in the short term, and the climate will continue to warm in the next decade. Therefore, it is more important to adapt to climate change, especially for developing countries with weak ability to cope with climate change. The main measures to adapt to climate change include improving crop varieties, cultivating and breeding stress-resistant varieties, adjusting the structure and layout of grain industry and developing water-saving agriculture. In terms of water resources, we should strengthen the management and storage of water resources, save water, develop air water resources and desalinate seawater. In people's life, we should improve public health infrastructure and establish an early warning system for diseases induced by climate change; We should also strengthen the monitoring of sea level rise and build protective dams. Especially climate change education, I think it should be carried out among the whole people, from primary school textbooks to cadre training materials, from middle schools, universities and graduate education. I think climate change is not an expedient measure, but an issue to be discussed from today to the next few decades. I'm afraid it will take a generation or two, so I think education and scientific research must go ahead.
Climate change is an environmental problem, but in the final analysis it is a development problem. This problem emerged in the process of development and should be solved under the framework of sustainable development. We should adhere to the principle of "common but differentiated responsibilities" established by the United Nations Framework Convention on Climate Change. This principle not only reflects the differences in economic development level, historical responsibility and current per capita emission level of different countries, but also is the basis for maintaining and making progress in future international cooperation. The process of industrialization, urbanization and modernization in developing countries is far from complete, and the task of developing economy and improving people's livelihood is arduous. Scientifically understanding the uncertainty of future climate change, strengthening scientific research, constantly improving and improving human understanding of the climate system and its changes, improving the accuracy of future climate change prediction, enhancing China's ability to cope with future climate change, actively taking adaptation and mitigation measures, and constantly improving the level and level of ecological environmental protection are important contents of comprehensively implementing Scientific Outlook on Development and building a harmonious socialist society, and are also the common aspirations of the China government, the public and the scientific community.
To this end, I put forward some suggestions to deal with climate change:
First, climate system monitoring. We should improve the monitoring ability of the climate system as soon as possible, establish a relatively perfect climate observation system and obtain much-needed scientific data.
Studying and mastering the laws of nature and accurately grasping the relationship between human activities and climate change is an important foundation and prerequisite for promoting the harmony between man and nature, and timely obtaining the monitoring data of climate system is a necessary condition for carrying out climate change research. At present, China's climate system observation is seriously lagging behind, which has become a bottleneck restricting scientific and technological progress in related fields. Strengthening the observation of the climate system will not only help to improve China's scientific and technological level and service ability in the field of climate change, but also provide effective services for diplomatic negotiations.
Second, climate change research. Strengthen climate change research, reduce the uncertainty of climate change and its impact assessment results, and provide more comprehensive and accurate services for further adaptation and mitigation measures.
The climate system is extremely complex and full of variables, which poses a great challenge to accurately predict future climate change, but it is also urgently needed information for national economic and social development. We should continue to increase scientific and technological input in the field of climate change. On the basis of strengthening the observation of climate system, we should deeply understand the various physical, chemical and biological processes existing in the climate system and the relationship between various elements, vigorously promote scientific and technological innovation, develop climate system models with independent intellectual property rights, establish scientific and technological support systems in the field of climate change, meet the needs of China's economic and social development, and improve the scientific and technological support capacity of international negotiations.
Third, adapt to and slow down climate change. Mitigation and adaptation measures should be taken at the same time. In the near future, measures should be taken to adapt to climate change, and the response and management of extreme weather events and natural disasters should be strengthened to minimize risks.
The trend of global warming is inevitable, meteorological disasters will become more and more serious on the whole, and people's lives and property and national economic losses may increase gradually. As far as China's current economic and social development is concerned, it is more realistic and urgent to take adaptive measures, especially for extreme weather events and meteorological disasters. The contribution of disaster prevention and mitigation will be of great benefit to the future. It is necessary to effectively strengthen the early warning of meteorological disasters, especially vulnerable areas and departments, improve the comprehensive response ability of meteorological disasters, reduce the economic threat of disasters, resolve social contradictions in disasters, and eliminate political turmoil in disasters.
Fourth, climate change impact assessment. Strengthen the research and evaluation of the impact of climate change on various regions, departments and industries in China, so as to help governments at all levels grasp macro-strategic decisions on adapting to and mitigating climate change, take effective adaptation measures for regions and departments, and provide targeted decision-making services.
To take measures to adapt to and slow down climate change, we must first fully understand the multi-level and all-round impact of climate change on the development of natural ecosystems and economic and social ecosystems and its future development trend. Strengthen the comprehensive impact assessment of climate change on natural ecology and environmental evolution, economic and social development, major engineering construction and urban development, guide the whole society to adhere to the concept of Scientific Outlook on Development and sustainable development while vigorously developing the economy, fully consider the comprehensive impact of climate change, minimize the economic and social costs of adapting to and slowing down climate change, and take the road of harmonious development between man and nature.
Fifth, strengthen climate change legislation. Strengthen climate change legislation, effectively respond to the international community's call for emission reduction, and effectively implement strategic decisions and specific measures to adapt to and mitigate climate change.
Generally speaking, the negative impact of climate change on China is greater than the positive impact. The gradual change and drastic change of climate will pose a serious threat to China's natural and economic system, and excessive long-term energy consumption will also endanger energy security. While continuing to seek to change the mode of economic growth and formulate specific supporting measures, we should strengthen legislation to deal with climate change, standardize the responsibilities and obligations of the whole society by formulating and implementing scientific economic policies, social policies and environmental policies, make climate protection a conscious action of the whole society, ensure the implementation of countermeasures, and actively respond to international calls for emission reduction in a pragmatic manner.