Prior to humans industrializing the Sahara desert was green, 11,000 - 5,000 years ago.
https://www.nature.com/scitable/knowledge/library/green-saha...
The world regularly adjusts, California has had more fires historically (and less).
https://www.pnas.org/content/early/2012/02/09/1112839109
I agree things are changing, but it's not clear who or what is causing it. That's really my only thoughts on the subject. Seems CO2 has a smaller impact than what ever has caused the Sahara to turn into a desert.