Consider carefully the affects of super weapons such as nuclear bombs. Proliferation is unstoppable. It may serve to stabilize governments, however, it also might serve to increase violence, especially if there are less consequences than the nuke. Pollution will affect the world. Radioactive waste has to be held safe for the rest of eternity.
Many industrial chemicals are toxic and carcinogenic.
Today, the government requires them to be stored safely, however if government falls, there is nothing to prevent the corporations from dumping them, preferably on other people's land. If new fuels or forms of transportation are created, air pollution will reduce in severity. Think about polution-control domes, carbon filter masks, airlocks, fashionable gas masks and chemical isolation suits. New viruses, plagues, and germs will probably be created, both by corporations and nature. Consider the effect that plagues will have on society.