It is a metaphor that things have reached a desperate situation and suddenly there is a new turn for the better.
On one side of the boat, Qian Fan races; At the head of the sick tree, every year is a spring shower. (Liu Yuxi's "Rewarding Lotte Yangzhou for Dinner")
Of new things will replace old things.
The bleak autumn wind is changing the world again today. (Mao Zedong's "Langtaosha Beidaihe")
I think changes can be written as natural changes, social changes and changes in people's lifestyles.