Since all problems are caused by human nature, should we start to improve human nature intentionally and continually from now?
I believe this is a very important question. Imporve human nature can reach the root of problems.
Even if we will not be able to see the great outcome but if we do not start now how can our offsprings to see the result in the future?
If there is such a thing as human nature, it is not really changeable. The whole idea of human nature is that this is what we are by nature and not by choice. If that is truly the case, then there is no way to change it.
So what it boils down to is whether we should try to change cultural attitudes that are so deeply set in our minds that we think of them as simple human nature. This would be things like the desire for more wealth and power.
If by "we" you mean the government, I would say no. The government should not be in the business of trying to change our values. That's too much like totalitarianism for me. But should other institutions (churches, families, education) try to change our ways so as to reduce problems? That would be great. It would be nice if we could move away from being so materialistic and greedy and it would solve many of our problems. However, if these things are truly part of our human nature, we won't be changing them short of Brave New World tactics.