> I'm declaring war on the sahara desert by planting trees. Billions must grow.. TOTAL DESERT DEATH

https://netzsphaere.xyz/objects/d1c037d6-1dfa-499f-8823-d217a798ad9a

That only works a little. There were once trees in portions of what is now the Sahara Desert, but trees need water to survive. I expect we have not yet found a way to increase that area's rainfall without transforming another area into a perpetual drought zone®.