Using China culture and marked by research methods and materials, Mr. Zhu divided the general trend of climate change in China in the past 5,000 years into four stages: 1. The archaeological period was about 3000 ~ 1000 BC; Second, phenology (BC 1000 ~ AD 1400); Third, the period of local chronicles (A.D. 1400 ~ 1900); Fourth, the observation period of instrumental music. Archaeological period is ancient, there is no literature, and there are few documents. One of the important cultural sites in this period is banpo village near Xi 'an, which existed about 5,600 to 6,000 years ago and belonged to Yangshao culture. Among the animals hunted by primitive people found in this site are snapper and bamboo rat. Now these animals only exist in the subtropical zone, but not in Xi 'an, so it is inferred that the climate at that time must be warmer and wetter than now. In Anyang, Henan Province, there is another site-Yin Ruins, which is the old capital of Yin Shang Dynasty (about1400 ~100 BC). Besides hydra and bamboo rat, there are fish, buffalo and wild boar, and even animals that only exist in the tropics today. Since this era, China has recorded Chinese characters. Thousands of Oracle Bone Inscriptions in the Yin Dynasty recorded words related to rain and snow. At that time, the time for planting rice in Anyang was equivalent to March in the current solar calendar, and now it will be mid-April. Oracle Bone Inscriptions also recorded that a Shang king got an elephant while hunting, which was related to the ancient place name "Yu" in Henan, and it was a sign that people were holding an elephant. It can be seen that Henan was warmer than now. Further east, in Licheng County, Shandong Province, carbonized bamboo joints were found in Longshan cultural site. According to these findings, Mr. Zhu believes that compared with the average temperature and annual average temperature in the lower reaches of the Yellow River and the Yangtze River today, the temperature in normal months is 3℃ ~ 5℃ lower than that at that time, and the annual average temperature is about 2℃ lower. In view of some people's misconception that the climate will not change after the ice age, he pointed out in particular that the climate change in historical period is the same as that in geological period, but only to a small extent.

The second and third phases mainly use historical phenological records to infer climate change, while the third phase mainly uses China's rich local chronicles, and its phenological records are more concentrated and easier to use. Although there were no meteorological instruments to observe climate change in ancient times, there were abundant phenological records. The so-called phenology means that people observe when it rains and snows, when rivers talk and freeze, when plants blossom and bear fruit, when migratory birds come in spring and leave in autumn, and so on. In order to meet the needs of agriculture, China began to observe phenology from the Western Zhou Dynasty (about 1 100 ~ 770 BC) at the latest. Xia He's Book of Rites and Moon Order recorded the phenological observation results at that time. This observation has accumulated for 3,000 years, and it is rich in experience and well documented. This is an expensive historical climate research material. For example, in the Xia and Yin Dynasties, Tan Guo (in today's Shandong Province) judged the arrival of the vernal equinox by the north of the swallow. In the spring equinox of 1930s, the swallows only flew to Shanghai, but not to the north of Shanghai. In contrast, the annual average temperature in Shanghai is 65,438 0.5℃ different from that in the north of Shanghai. This result is consistent with the conclusion that the temperature was estimated by the method of bamboo distribution change in archaeological period.

There were inscriptions on bronzes in the early Zhou Dynasty, and later there were more inscriptions on bamboo slips. Bamboo slips and many characters widely used at that time were headed by "bamboo", indicating that the weather was warm at the beginning of the week and bamboo was widely planted in the Yellow River basin, which was very different from now. In the middle of Zhou Dynasty, the climate turned cold. The Chronicle of Bamboo Slips records that the Hanshui River was frozen once in Zhou Dynasty, which happened from 903 BC to 897 BC. However, in the spring and autumn after 1200 years, the weather turned warmer again. Subtropical plants such as bamboo and plum trees are often mentioned in The Book of Songs. For example, Qin Feng said, "What is it? There is a plum. " This mountain is in the south of Xi 'an, and now there is no trace of plum trees. During the Warring States, the Qin Dynasty and the Western Han Dynasty, the climate was always warm, but it became cold in the Eastern Han Dynasty, but it didn't last long. By the Wei, Jin, Southern and Northern Dynasties, the climate really cooled down, and the first half of the fourth century was extremely cold. Bohai Bay has been frozen for three years in a row, so it is feasible to have horses and chariots on the ice. In the middle of the 6th century, Jia Sixie of the Northern Dynasties wrote an agricultural encyclopedia, Qi Yao Min Shu, which attached great importance to phenology. It is mentioned in the book that pomegranate trees in Shandong, Henan Province will be wrapped with cattail from the middle of 10, otherwise they will freeze to death, but today pomegranate trees in these places can grow safely outdoors without wrapping.

After Sui and Tang Dynasties, the weather became warmer again. According to records, there was no ice and snow in the winter of 650, 669 and 678. At the beginning of the eighth century, there were plum trees and oranges in the palace. Plum trees can only tolerate cold to-14, and oranges can only tolerate -8℃, which proves that the climate is warm. But by the Song Dynasty at the beginning of 1 1 century, there were no plum trees in the north, and the climate was colder than that in the Tang Dynasty. In the twelfth century, the climate continued to get cold. In111/year, Taihu Lake was not only completely frozen, but also allowed to drive on the ice, and all the oranges in Dongting Mountain on the lake froze to death. 1 13 1 year to 1260, it snowed during the Spring Festival in Hangzhou. On average, the latest date of snowfall every ten years is April 9th, which is nearly one month later than that of Chun Xue in the12nd century and the last ten years. /kloc-The cold of the 20th century extends from north to south to the south and southwest of China. 1 1 10 and1/78, all litchi in Fuzhou were frozen to death. Litchi used to grow in Chengdu, Sichuan. Zhang Ji's "Chengdu Qu" says: "The smoke in the west of Jinjiang is green, and the litchi on the hill of Xinyu is ripe." But by the time Su Shi lived in the Northern Song Dynasty, litchi could already grow in Meishan, south of Chengdu. In the Southern Song Dynasty in the12nd century, according to Lu You's poems and Fan Chengda's Wu, Meishan did not even grow lychees.

Although the weather showed signs of warming in the early and middle thirteenth century, it became cold again in the fourteenth century. Taihu Lake was frozen again in 1329 and 1353. Ice drifted from the Yellow River to Shandong in 135 1 year1kloc-0/month. Modern records show that ice did not appear in rivers in Henan and Shandong until1February. It is worth noting that from a global perspective, climate change seems to be advancing from east to west. According to the research of scientists in the former Soviet Union and Europe, the cold period of the Russian plain began in about 135o, and the climate of Germany and Austria in Central Europe began to deteriorate obviously in 1429- 1465. In Britain, some people think that the famines in 1430, 1550 and 1590 were all caused by cold weather. Therefore, Mr. Zhu thinks that "the cold trend may start from East Asia and gradually move westward to Western Europe".