As I've mentioned multiple times, I'm writing a military sci-fi novel. The focus of the story is war, and that happens far away from Earth. However, I'm starting with my MC's "normal", on Earth. It is this "normal" that I'd like to ask about.
I've set the story in the future because for it to be possible, I need FTL, as well as the technological ability to start colonising other planets. To the extent that the MC is supposed to be "the boy next door", I don't need much of a technological or social change on Earth. Moreover, significant changes from the modern life we know would distract from the story I wish to tell.
It's not that I cannot accommodate change. I have my characters getting around on autonomous drones rather than cars - that's easy. And I can mention in passing that Manhattan is all underwater now, if I like, but it would serve no purpose in my story, it would just be there.
Basically, if I set my story 100 years into the future, some things on Earth will have changed. Quite a few of those things my characters would be aware of, but they do not serve my story in any way. Those changes include technology, society, politics, climate...
How do I balance keeping my setting realistic (that is - presenting the future as I imagine it is likely to be) against avoiding flooding the reader with information not directly relevant to the story?
For example, climate change is likely. During the MC's time on Earth, he would naturally see the effects of climate change, such as a different rain pattern from what we have today. He wouldn't see it as "different", he'd just have rain when the reader wouldn't expect that. However, such rain is not directly relevant to the story, and might be confusing to the reader. I can avoid having that rain, but then the setting is less realistic.
Each particular detail (such as the rain example) can go either way, but put together, they create a picture that I'm struggling to balance.