>>11797599well thanks to cornachan we already where masks all the time now, it wouldn't be so far fetched if this was found to be enough of an issue that oxygen-rich respirators started to hit the market. oxygen could begin to be piped into a tank in your home or office the same way gas and water is. I don't think it would take many changes (airlock-type rooms, tighter seals, windows that dont open) to building design to keep inside and outside air reasonably separate.
That's all assuming that this becomes enough of a problem, but it could be mitigated just fine although at some cost. We didn't get to this stage of development by panicking and giving up when conditions deteriorated. If the environment really takes a turn for the worst life may get shittier but humanity will be fine.