Even the Archive of the page has the paywall, annoyingly https://web.archive.org/web/20260115182034/https://www.nationalgeographic.com/science/article/china-great-green-wall-gobi-tengger-desertification

Well their only citations are:

• One anecdotal account

• Feng Wang, associate professor at the Institute of Desertification Studies at the Chinese Academy of Forestry

• And the movie “Interstellar”.