The whole idea of interstellar travel was created by fiction writers, but because it has many elements of good science in it, it is a very persuasive idea. It is an idea located smack in the middle of the "gray area" between fantasy and reality, and this is what inspires people to try to imagine ways to make it a reality. One thing we do know is that it will be an expensive venture requiring an investment at the level of many percent of an entire planet's GDP. Faced with the mounting impact of climate change, will Society have enough spare change for this kind of undertaking?
By some estimates, the first interstellar voyage will cost many trillions of dollars, require decades to construct and involve tens to hundreds of passengers and explorers. It will certainly cost more than the $100 billion for our first manned trip to Mars! Assuming a project of this scope can even be sold to the teeming humanity that will be left behind to pay the bills, how will the destination be selected? Will we just point the ship towards any star and commit these resources to a random journey and outcome, or will we know a LOT about where we are going before the fuel is loaded? Most of us will agree that the latter case for such an expensive "one off" mission is more likely.
This is a short sighted technological vision, and rather presumptuous. Who says humanity will even be 'allowed' to travel to other star systems? Humans have a nasty historical record of horrendous warfare and messing up their environment up to a fare the well.To read more, click here.