100 years from now:

 I don't know if there are nations anymore then. For example, the U.S., Russia, and China and history as we know it might  no longer exist in any recognizable form simply because all wooden structures and possibly all plants on the surface of the earth could be gone, blown away or washed away by Global Climate changes.

However, what I do know is that there will still be under 1 billion people still alive on earth, mostly living under the earth because winds above ground will be so severe some times during the year. The winds are what destroys all wooden structures on earth. There likely will still be cement reinforced structures that aren't too tall still so the wind goes up and over them sort of more like dome like structures that the wind couldn't blow down that are made of cement and rocks and rebar. But, even these would need steel shutters especially designed that can withstand 300 to 500 mile per hour winds which will occur periodically at all points on earth some time during every year at that point. 

Ocean waves during these times might reach 1000 feet in altitude so places like Florida, and elevations below1000 to 5000 feet near any ocean or large body of water will be washed away. 

Trying to stop these weather changes will for the most part be unsuccessful even though  Terraforming and weather alterations to some degree might be successful. But, not successful enough that humans won't have to live underground or go underground when the weather and winds get bad enough. So, human travel above ground only exists when weather is good enough whether from place to place or out into space. Many people will live in space or travel to other worlds by then if they are rich enough and many will die in the storms during the next 100 years time. 7/8 of the number of humans now on earth will be gone then mostly caused by the last 15,000 to 25,000 years of human progress and technology and overpopulation. Most animals and plants will be blown away except for plants and animals that humans moved underground with them in order to grow food to live in large underground caverns that will be solar powered or water or wind powered. Everything as you can see is going to change. So, governments, at least as we presently know them could all be gone then.

The point is people either do what it takes to survive all this or they are gone. Period.

So, planning is everything now for the future of mankind here on earth.