Why do you think burnett is convinced that "future generations will condemn" the forced removal of the cherokee? was he corect?

Yes.  To gain more land, they displaced the real owners from their ancestral home.  Many were driven out against their will and had to endure a terrible journey where many of them died.  He felt that it was an injustice and today many people share that point of view.

demand is the need and oportunity to buy a given good or service.

the causes of the dust bowls were severe droughts,   lands became dry and hard, temperature was higher than usual, hot and dry conditions killed crops, high winds. because of those factors, the winds kicked up dry soil and created clouds of dust.