Help me check on China Historical Geography Network. What are the stages of temperature changes in the historical period of China? Have there been any changes since the late Qing Dynasty?

From the Western Zhou Dynasty to the Han Dynasty, the temperature gradually increased and reached its climax in the Han Dynasty. The fluctuation of Chinese and foreign forces is also reflected in the temperature. As the temperature rose, the Han people went on an expedition to the wasteland, but the temperature dropped, and foreigners invaded China. After the Han Dynasty, the temperature dropped year by year, and this cooling flow has been accompanied by the great turmoil in the Central Plains-the Five Chaos, and the temperature slowly rose in the Southern and Northern Dynasties. Until the Sui and Tang Dynasties, the temperature rose sharply, the orthodox dynasty quickly unified the whole country, and the feudal society entered another golden age. But at this stage, it is the period when the ice in the Arctic Canada melts rapidly-what European scholars call the Little Ice Age. For hundreds of years, the temperature has dropped rapidly, and the global grain production has been greatly reduced. At this time, China was being bullied in the Song Dynasty. The temperature reached its lowest point in the Southern Song Dynasty, and China fell for the first time. The temperature rose steadily during the Ming and Qing Dynasties, and it is still rising, which also indicates the recurrence of some history.