I agree with mwalter that finding and using renewable energy is expensive and it will take some time before there is some real change. However, I think it's something that should be made a priority.
One argument that you could use in support of renewable energy is that, for America, it could be our solution to energy independence. Currently, we rely heavily on other countries for oil. This puts us in a a difficult situation. If we can find and use renewable energy in a sustainable and affordable way, we will no longer have to depend on foreign oil.