How cold was the ancient winter in China?

In the long ancient times, from 3 BC to the present five thousand years, China's climate also experienced great fluctuations, and the cold climate occurred indirectly. According to the paper "A Preliminary Study on Climate Change in China in the Last Five Thousand Years" by the famous meteorologist Zhu Kezhen, there were four relatively long cold periods in the history of China. The first cold period was in the early years of the Western Zhou Dynasty, which lasted for one or two centuries. The second cold climate period occurred from the early years of the Eastern Han Dynasty to the second half of the 3rd century A.D., which was a process of gradual cooling, and then in the 7th century A.D., and then began to warm up. The hundreds of years from cooling to warming were the period of confrontation between the Five Chaos and the Southern and Northern Dynasties, which was the most chaotic time in China. The third cold period occurred in the early 12th century, and the climate in China became colder and colder. It was first recorded in 1111 that Taihu Lake, which covers an area of 2,25 square kilometers between Jiangsu and Zhejiang, was not only frozen, but also open to traffic. All the oranges in Dongting Mountain of Taihu Lake froze to death, and the snow fell in Hangzhou, the capital of the Southern Song Dynasty, until late spring. This cold period lasted for more than 2 years. The fourth cold period was the 17th century, which was the last time of the Ming Dynasty.

First of all, put on more clothes and keep warm. Cotton is an exotic crop, which was not popular in the whole country until the Ming Dynasty. Before that, most people could not wear cotton-padded clothes. Pueraria lobata, hemp and silk are all local textile materials in China. Rich people naturally use silk. When the weather is cold, they will put silk brocade in their clothes to keep warm, and they will also wear fur made of animal skins such as lamb skin, fox fur and mink. As for the poor people who use linen or other fabrics woven from plant fibers, the effect of keeping out the cold is naturally unsatisfactory. Fortunately, by the Ming Dynasty, people could generally put on cotton-padded clothes.

The Tang and Song Dynasties were in the middle of the interglacial period, and there was a process of temperature rising and warming up for hundreds of years. Later, in the Yuan and Ming Dynasties, the so-called greenhouse effect appeared again after the process of temperature falling. However, from a professional point of view, the ability of carbon dioxide seems to be not so great, and the change of temperature by carbon dioxide has always been controversial. Although the current mainstream is that carbon dioxide causes the greenhouse effect, many people think that the beginning of the industrial revolution happened to meet with the temperature rising at the end of the interglacial period.

The average winter temperature in Beijing in the Ming Dynasty may be about 2℃ lower than it is now. The lowest temperature in winter along the southeast coast in the early Qing Dynasty may be 5℃~7℃ lower than it is now. In the sixth year of Hongzhi (1493), heavy snow fell in the Huaihe River Basin, which didn't stop until February of the following year, that is to say, it snowed for half a year. In December of the 11th year of Xianfeng (1861), heavy snow fell in Pu Yin, Hubei Province, and the ground was five or six feet deep, killing many people and animals. Wang Yue, a Qing dynasty poet, once wrote a poem describing the frozen scene of Qiantang River in the 18th year of Guangxu (1893)-"The atmosphere of the earth is not warm, and it is doubtful that it will be flooded. Once heard of qiantang bore, frozen flat as a rock. I also smell Huai seaside, and I hope to walk on ice. It's ancient, but I was born here. " An old saying shows the degree of cold in those days.

The ancients found that when the soil around the stove was roasted by fire, its properties would change, which not only hardened, but also kept warm for a long time, so they invented the heating method of "roasting the ground", which is also known as "roasting the hot ground". It is to heat a clean flat ground with fire, keep it warm by using the thermal inertia of the soil, and the warmer can lie on it to keep out the cold. This method of heating is also recorded in Zuo Zhuan. In the tenth year of Lu Zhaogong, Song Pinggong, the monarch of Song State, died, and his son Song Yuangong had a wake, so he needed to "sleep on the grass" and could not wear clothes to keep out the cold. This didn't kill his son. At this time, an attendant named Yu Sun warmed up the place where Yuan Gong was sitting with fire in advance to please the monarch, and Song Yuan Gong, who was comfortably awake, was very happy. He originally hated Yu Sun, was flattered by people, and was immediately elated, and he was promoted to rank ~