I had a cold and took a day off. The strongest cold snap is coming, and Taiwan is also cold, and there is a chance of snowfall in some areas. There are two nagging sentences here, Guangzhou's latitude is more south than Taiwan, at least it's about the same, Guangzhou's historical record is snow. If it is said that because of the greenhouse effect, it causes extreme cold and heat, then did it also have a greenhouse effect in ancient times?