If its really just a half conscious defensive trigger, thanks to you and your kind responsible for that development.
I'm sure we can survive fairly reasonably in whatever climate we end up with in a few hundred/thousand years, but the gap in between is a really doozy. The stories and myths about the selfish people of our times will go on for millennia.
It is the book series 'Carbon Ideologies' by William T Volleman, the opening few pages are written to those that read them in a few hundred years. Those that read these today are already convinced, those in the future will want answers. All he does is use examples of how we live to point out that we are not inherently evil, just looking out for our more immediate needs.
Except there is nothing inherently more selfish about ”people” today than at any point in history.
If anything, it might change humanity’s view of itself, and its capability to collectively handle major threats.
With the size of populations, there's less feeling of individual impact. If I don't do "my bit" then it's such a miniscule negative to society as a whole, it won't really matter.
We have a relatively new economic principle that if everyone acts in their own best interests, that will also further society's interests. That means there's no moral choice between what benefits me and what benefits others, I can always pick what benefits me.
These aren't universal, but are two simple reasons why selfishness could be more prevalent now than a lot of history.