Will non-sustainable developments become halted?

Both. As non-sustainable practices begin to have more and more consequences we will be forced to find alternatives, and often will not find the alternative in time to prevent significant suffering. In some areas we may have enough foresight to change before the impact is felt. I am encouraged to see more and more wind power being installed, both on land and on ocean based platforms, but at the same time I am discouraged to see people choosing to drive large SUV's which will have a negative impact on the future. In some areas reforestation is taking place, where 100 years ago there was deforestation. This is encouraging and is simply the result of changing economic use. I have also been encouraged to see negative population growth in the most industrialized countries; this suggests the present stresses on the planet may be relieved.