The Green Paper on Climate Change: The Haze Situation in China in the Report on Responding to Climate Change (20 13)

Statistics show that the causes of smog weather in China have obvious seasonal changes. From 198 1 to 20 10, the frequency of haze weather in winter is obviously higher than that in summer, and the number of haze days in winter accounts for 42.3% of the whole year.

From the time span, from 196 1 year to 20 12 year, the average number of haze days in central and eastern China (east of east longitude 100) showed an overall increasing trend. The number of haze days in recent 52 years is 1980, 35.8 days. Before 1980s, the average number of foggy days in central and eastern China was basically more than three times that of haze days. Since 1980s, the number of foggy days has been decreasing, while the number of haze days has been increasing, and the proportion of haze days has gradually decreased, especially in 20 1 1 year and 20 12 years. It is understood that fog is composed of water vapor. When it is cold, it will form fog, and fog itself is not a kind of pollution. Haze is composed of fine particles, which are basically of micron order, unlike fog, which is of the order of ten or twenty microns. The smog process that lasted for 6 days is three times that of the past! The Green Paper pointed out that although the number of continuous haze stations in the central and eastern regions increased slightly in the 20th century, the overall change was not significant, but after entering the 20th century, the number of continuous haze stations increased significantly.

The data showed that the average monitoring values of haze stations lasting more than 3 days from 200 1 to 20 12 were more than 2 times of the average monitoring values from 196 1 to 2000, and the monitoring data of haze stations lasting 6 days were 3. 1 times of the control data. In the past 10 months, the smog in the central and eastern regions showed a high incidence. Since 20 13, the average number of haze days in China has been 4.7 days, 2.3 days more than the normal period (2.4 days), and the most since 52 years (196 1 -20 13). Among them, Heilongjiang, Liaoning, Hebei, Shandong, Shanxi, Henan, Anhui, Hunan, Hubei, Zhejiang, Jiangxi, Jiangsu, Chongqing and so on. The largest number in the same period in history. The local smog in the central and eastern regions exceeded 100 days.

In terms of spatial distribution, the number of haze days increased in the east and decreased in the west. The number of haze days in Northeast China, Northwest China and Southwest China decreases by 0-0.5 days every year, and the number of haze days in the western region is basically less than 5 days except northern Xinjiang. North China, the middle and lower reaches of the Yangtze River and South China showed an increasing trend, among which the Pearl River Delta region and the Yangtze River Delta region increased the fastest, and Shenzhen, Guangdong and Nanjing, Jiangsu increased by 4. 1 day and 3.9 days annually. The number of haze days in most parts of central and eastern China ranges from 25 days to 100 days, and some areas exceed 100 days.

The Green Paper selects six typical big cities (Beijing, Shijiazhuang, Zhengzhou, Nanjing, Hangzhou and Guangzhou) and six nearby small towns (Zunhua, Raoyang, Xihua, Gaoyou, Cixi and Zengcheng) in central and eastern China. By comparing and analyzing the changes of annual haze days, it can be seen that before the mid-1970s, there was little difference between the annual haze days in big cities and small towns, but since the late 1970s,