The increase in number of people
        
             
        
        
        
You cant settle in deserts due to lack of water and scarcity of food, which led to the Saharan regions being less populated. Hope this helps. 
 
        
             
        
        
        
Answer:
Human Deforestation
It's a necessary evil. But deforestation is undeniably harming our environment by contributing to climate change. Forests are very important, because they influence climate through exchanges of energy, water, carbon dioxide, and other chemical species with the atmosphere
Explanation:
hope this answer helped you
 
        
                    
             
        
        
        
Well if you are adding sides to something then that makes that object HAVE to go bigger. That will affect the area. So making it bigger by forcing more sides onto a object.This way making you area getting bigger. Hope that helped. :) :) :) :).