Why is it getting colder every year?

Reporter: What caused the heavy snowfall in parts of northern China? Zhang Qiang: The adjustment of atmospheric circulation and the frequent activity of strong cold air are the main reasons for the recent heavy snowfall in the north. Since the end of 10, the atmospheric circulation in the middle and high latitudes has been obviously adjusted, and the longitude of Eurasian circulation has increased, showing a distribution of two ridges and one trough, which is a typical distribution situation of heavy precipitation in China. In this circulation situation, strong cold air directly moves south from the polar regions, with high intensity and frequent activities, which brings strong cooling to China. At the same time, the subtropical high in the western Pacific is stronger than normal, the west is north, the Indo-Myanmar trough is stronger, the southwest water vapor transport to the north is extremely strong, and the low-level water vapor reflux from the East China Sea is also extremely strong, providing abundant water vapor conditions for rain and snow. Two warm and humid air currents from the south and strong cold air from the polar regions meet in the northwest and east of North China, forming a large-scale continuous rain and snow weather. Will it move south? 1precipitation area in late October 165438+ Nanya reporter: The recent snowfall mainly occurred in the north. Will it expand southward in the future? Zhang Qiang: Compared with the normal period, it is estimated that the precipitation in the southeast of northwest China, the south of Huanghuai, Jianghuai, Jianghan, Jiangnan and the east of southwest China is more than normal, and the precipitation in other parts of the country is less than normal. Due to the frequent cold air activity, the temperature in most parts of China will be lower than normal from mid-October/early days of kloc-0/65438+,and from mid-February/early days of kloc-0/65438+,the cold air activity will be weak and the temperature will be higher than normal. According to the latest marine atmospheric anomaly analysis and dynamic climate model prediction, it is predicted that the main precipitation areas in China will start to compress southward from the middle and late October of 165438/kloc-0+12 in early February, and the precipitation will mainly be located in the south of Huaihe River. How to prevent it? Reporter: Can you tell us what measures should be taken to prevent disastrous weather in the coming month? Zhang Qiang: In the coming 1 month, severe rain and snow weather will occur in Henan, Anhui, Shandong, Shaanxi, Hubei, Hunan, Guizhou and Sichuan, which may affect facilities agriculture, transportation, forestry, electric power and other departments. Affected by cold air, the temperature in Beijing, Tianjin, Hebei, Shanxi, Shaanxi and Northeast China will be further reduced. Crops need to be heated and insulated to prevent freezing injury, and field management of wheat should be strengthened before winter to prevent freezing injury. Special attention should be paid to the influence of road icing on traffic in the first snow area. Hebei, Henan, Shanxi, Shaanxi and other areas with serious ground snow should pay close attention to the possibility that rising temperature and melting snow may cause mudslides and landslides in some areas. In addition, after heavy snow, the relative humidity at the bottom of the atmosphere is high, and radiation cools at night and early morning, which is prone to foggy weather. All expressways should strengthen management and do a good job in early warning and defense of civil aviation and highways. In-depth analysis of laissez-faire climate change may raise the temperature by 5 degrees Celsius in this century. This difference has caught up with the difference between today's climate and the last ice age ... The climate difference between today and the last ice age was formed for thousands of years, and man-made climate change only took a short century. Climate expert 1 At present, the El Ni? o phenomenon is moderately weak. At present, the developing El Ni? o event in the tropical Middle East and Pacific Ocean also has a certain indirect impact on the large-scale rain and snow weather process in China. Since June, the sea surface temperature in the Middle East and the Pacific Ocean has reached the El Ni? o state, and the rising speed has become gentle. The sea surface temperature has basically remained warm at 0.5 ~ 1.0℃, and some areas have reached 1℃, which is a moderately weak El Ni? o event. After mid-June, 5438+10, the sea surface temperature increased, and the response of the atmosphere to the sea surface temperature was accelerated and stable. The influence of El Nino events on China's climate through tropical circulation began to appear gradually, and precipitation in southern China began to increase. However, it is still unknown whether El Nino phenomenon has a significant impact on the global climate at present, because although some countries or regions have suffered from snowstorm weather, it did not happen under the background of typical strong El Nino phenomenon. At present, the El Ni? o phenomenon is moderately weak and is also an atypical El Ni? o event. The weather is normal in most parts of the world. "At present, the weather conditions in most parts of the world are normal, and some areas have experienced more extreme weather conditions." He said that taking China as an example, on the whole, the heavy snowfall in North China was abnormal, but the snowfall in some areas did not exceed that in the past. According to Director Zhang Qiang, under the background of global warming, the probability of high temperature, high fever and strong convective weather will be higher, while the probability of low temperature events will be smaller. Blizzard weather in some areas is not directly related to climate warming. 2. The intensification of industrialization aggravates the climate anomaly. "Even if the temperature rises by only 2 degrees Celsius compared with that before industrialization, it will lead to the emergence of new weather types, which will have a global impact and the weather will become more and more changeable. Extreme weather events occur more and more frequently and violently. What is terrible is that letting climate change go unchecked may raise the temperature by 5 degrees Celsius in this century. " Lin Xiawei Bibaum, dean of the School of Natural Resources and Environment at the University of Michigan and a climatologist, told reporters. Climate warming is generally considered as an important cause of extreme climate anomalies by academic circles, and human activities are warming the world. The fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC), which embodies the efforts of more than 2,000 scientists from all UN member countries, points out that the average temperature of the earth has increased by nearly 1 degree Celsius since the industrialization period. All kinds of disasters are more frequent. Lin Xiawei told reporters: "The rising average temperature of air and sea water, the melting of ice and snow, and the rising sea level show us the impact of climate change. The frequency of cold weather and frost weather decreases, while heat waves become more common. Although droughts in Australia, Central Asia, the Mediterranean, the Sahel region of Africa, the western United States and many other regions are more frequent and severe, global precipitation has generally increased. Heavy rains and floods have become more common, and the harm caused by storms and tropical cyclones, including their intensity, has increased. " China's geographical environment and population distribution are prone to disasters. In recent years, extreme weather, such as floods, typhoons and snowstorms, has frequently occurred in China, and the severity of each event tends to set a new record. As for the reasons why China is vulnerable to climate, Lin Xiawei analyzed that one of the reasons is that a large number of people live in coastal and low-lying areas; The second reason is that the environmental degradation caused by population growth and industrialization makes the management of land and other resources more complicated; The third reason is that industrialization and coastal development have destroyed a large number of marine resources. The accelerated melting of glaciers on the Qinghai-Tibet Plateau is restricted by factors such as population living area, unstable economic conditions, high proportion of agriculture, and limited funds and institutional capacity to adapt to climate change. Lin Xiawei believes that the costs caused by climate change (about 75% to 80%) will be borne by developing countries. "Policymakers in developing countries, including China, have noticed that more and more development budgets have been transferred to deal with weather-related emergencies." According to the research of the World Bank, China will be one of the countries most affected by climate change. According to the forecast, its temperature rise will exceed the world average level, and the sea level of the whole East China Sea will rise. The phenomenon of water shortage in the north is becoming more and more serious, and extreme weather events in the south are becoming more and more frequent. The glaciers on the Qinghai-Tibet Plateau, which replenish water for its main rivers, are accelerating to melt. Lin Xiawei concluded that dealing with extreme climate change should start with solving greenhouse gases, and building a climate smart world is the way out in the future. The key lies in the simultaneous action of developed and developing countries. ....