Bai still vividly remembers the desolate desert back then, where finger-thin saplings were watered ladle by ladle by Yin. At that time, Sakolsky had constant concerns about whether the tiny saplings could survive in the wasteland, which makes today"s sprawling 50,000-tree forest even more miraculous.

　　The changed and unchanged

　　Things have changed over the past 27 years. While waiting for Sakolsky, Yin jokingly said he got less hair, and she would not be able to recognize him if running up to him on street.

　　The passage of time has brought far more than personal aging, according to Bai, another witness to the decades-long changes. "Everyone is growing older. Our families have expanded with more children, local communities have grown in population, and the surrounding environment is constantly evolving, just as our cities are undergoing profound transformations."

　　On a night tour in Ordos on Sunday, Sakolsky, watching a fountain light show, said that "it is a 21st century city, but it looks like a 22nd century city. In the 2000s, Chinese government made a promise to Chinese people to beatify this country, and they succeeded."

　　For Sakolsky, probably the most profound transformation lies in the depth of his human connection forged.

　　"27 years ago, we were just friends and acquaintances. We are brother and sister now. So much has happened since then, but the important thing is many people have seen the story and now they can also help to make China beautiful," he told the reporters.

　　Through joint efforts of people like Yin, the Mu Us Desert has turned from wasteland into a green oasis. China has contributed about 25 percent of the world"s newly added green areas and taken the lead in achieving zero growth in land degradation, per official data.