I question if selfishness is learned, an innate part of the human mind, or both. I think we could hope to separate ourselves from it over time, but it would take a very long time. It's also very hard to change people's mindset without forcing them at gunpoint, which would also fall into the realm of what could be called a decision made at the expense of another. — TogetherTurtle

I agree, it would take a very long time. That's why the sooner everybody starts taking it seriously the better off we'll be later on down the line. And the goal isn't to change people's mindset at gunpoint, it's to do the best we can for everybody now so that those destructive mindsets are less common in the future. Holding a gun to somebody isn't doing the best we can, we can obviously do better than that.

Also, whether selfishness is learned, innate, or both, it's true that individual humans can grow to be more empathetic, and it's true that other humans can facilitate that kind of growth through the sharing of love. Therefore, selfishness in individuals/on a wider scale can be reduced, so we should try to make that happen as much as we can. Allowing ourselves to resign to the idea that it's just innate is too defeatist in my opinion.

If things are to change then those in power responsible for atrocious events or even simply poor decision making should be held to account. — Amity

I forgot to address this.
I agree, individuals should be accountable for their own actions. I just think that the ultimate goal should be to bring those individuals to a place where they genuinely repent and don't want to do those actions anymore. That's a difficult thing to do, but I believe it's possible, or at least worth a try. I'm saying we should all make more of an effort to lift those people up to build a better society with all of us, rather than just throwing them in a jail cell and hoping we never have to think about them again.

What will be your moral fundament of what is cruel and selfish when raising new generations? — Aleksander

As you suggested in another post, It's dangerous to mandate a one-dimensional moral doctrine, but I can tell you what I would preach if I was standing at the pulpit.
The core of what i'm talking about is honesty. Honest effort to understand the true effects of one's actions (though we can never fully understand), honest intent to create the best outcome overall, for all humans including oneself (Utilitarian I guess), and honest expression of one's feelings (to make the effects of action clearer).
I think even destructive feelings of rage and hatred should be communicated in some way, and when they are communicated, I think the whole community is responsible for helping the person through those patterns of destruction/self-destruction. Often, these expressions are ignored, condemned, or punished, and I believe that allows the destructive impulse to grow. Of course, even in the most nurturing environments, some people still hold onto hatred/selfishness and let it destroy them. I only think it would happen a lot less if everybody saw the growth and flourishing of the entire community as part of their individual responsibility. It's about effort and awareness on an individual level.

Welcome, mejonat.
I think what you think points to a basic and continuing problem for all living beings.
It is a power issue at different levels and interactions.
No matter what happens in the future, this will persist.
We have real problems right now which need to be addressed.
Some things are improving along with pressure groups and increased knowledge or awareness of what is actually going on.
If things are to change then those in power responsible for atrocious events or even simply poor decision making should be held to account. — Amity

Thank you.
I agree with what you say here, but I think that even this basic problem can be reduced in potency over time. I also believe that "solving the problem", though it can never be completely "solved", involves examining and dealing with the basic core processes involved. These are fundamental parts of our experience as humans, and what I described is the closest thing I can think of to the actual source of our problems. It's also important, I think, to reflect on how humans develop universally, not just as individuals, and what we can do to heal destructive tendencies. This is what I'm trying to point to.
I also agree that there are plenty of other problems that need to be addressed, but I don't think that's enough of a reason to forget about the fundamental problems. I think both need to be tackled. In my opinion, only focusing on the current problems (or the "real" ones) is like continually suppressing the symptoms without looking at healing the disease. We need to look to the future as well, and I actually believe we can do both.

If there is one big disaster we can point to that is approaching, it's probably something that is already manifesting in the form of small changes and problems in the world. I think all we can do is try to anticipate and prepare for those specific instances. So I guess I'm saying you have to name the specific problem before you can come up with a specific solution.

I think what causes many problems is that individual humans make choices at the expense of others/the environment, and they don't intend to mend the damage they caused. I'm generalizing, but I also think people that hurt other living things for personal gain are only comfortable doing so because they are selfish or bitter. It's a lack of love. Many times I think the community fails in raising them to be good people. So I think the best we can do to reduce the number of people that grow up to make selfish decisions is to take responsibility for showing love and respect to everyone in arm's reach. The more people that do that, the more that impulse will spread over time.

That's what I think.