Without overnight becoming truly altruistic, it would mean making some moral decisions that would be deeply unpleasant;I give not a flying toss for the future, as long as my current offspring manage to enjoy it and have a good life. Looking at further forward is irrelevant because I'm not suffering a shitty life just so future generations can have a good one.
I mean, it's my one and only life. I don't get another, I don't go to the back if the queue and wait my next turn. That's it. I'm just a ball of electrons bouncing around that makes me do stuff (still trying to find the ones responsible for my DIY efforts).
Until such time as human nature itself is changed so we work as one United Planetary Forum where each country's only goal is to help other countries get up to speed, and the sole local focus is quality of life for the inhabitants, we don't stand a chance.
Mankind scales down really well, but up really badly.
I.e For the UK, the UK Govt is strategic level, local authorities are tactical levels, and then operational level is all the services in your area. It scales again though as you go more granular. In a local authority, the senior management team are strategic, your departments are tactical and your staff on the ground are operational.
What we don't do, is up. We have tried - the EU, NATO, etc, but it's not enough.
Mankind is strategic level, and that's where as a species we need to focus. All wars stop, all funding goes into R&D for crops, water, energy. Overnight you'll solve the issues - look at Covid and what a ton of money and fear as incentive did for that solution.
So mankind's strategic aim is to bring every country onto the same footing technologically. Then that countries tactical aim is to make itself sustainable, its inhabitants fed, sheltered and clothed and it's operational is for its citizens to make it all happen
We could do this overnight. Overnight we could find all the solutions by getting rid of corruption, deceit, conflict, etc in our governments. We could pool all our resources, we could look at what is produced in this world and immediately stop production of the tat that we simply do not need.
BUT we can't. Because we're human. And we're cnuts.
How do we get the corrupt out of power in order for the altruism to take place. Probably by force or war.
We would also need to look at population control, oohhh thats a tough one.
We would need to take a review of religion and the messages that is pushing out, Holy war anyone!
Can the earth support its current population as it is currently dispersed, probably not, and we thought dingys in the channel was bad.
I could go on, but as you rightly say.... humans are cnuts!