Don't you watch Star Trek?
I envision a more homogenous world, the zeitgeist of this century is one of cultural exchange and adoption. McDonalds in China and Panda Wok in Montana. (K-pop, that's something to ponder). Information is instantaneous (factual or not). Environmental and political necessity will increase migration. This sharing cannot be suppressed.
There will be pockets of terrible suffering and probably another nuclear light show or two. But people will adapt and memenically evolve into a single society administered by local authorities.
Oh, and about half the animal species will be gone but we will have tackled safe clean energy production.