I'm one of those people that doesn't think we should try to "take care of the world". I prefer the older, time tested answer of what to do:
> You should be wise, brave, honest, temperate, and just, uphold tradition, and serve the public interest
As noted in the essay, this idea of "taking care of the world" is relatively new. PG claims it's because only now we can take care of the world, but I think it's just a naive idea that doesn't stand the test of time. I'm sure its not novel idea, and many others had thought of it and tried to implement some version of it in their society. But because it hasn't become cannon in any group or culture, it's a bad idea in that it doesn't produce human flourishing. Whereas ideas around wisdom, bravery, honesty, etc have replicated throughout cultures and led to everything we cherish
The idea is that you cannot take care of the world if you can't take care of yourself. So at first you must be these things. Ironically the most empathetic people I have met that purport to care most about "the world" are often the most dysfunctional people - substance abuse, medications, no strong family ties, anxiety, neuroticism, etc. These aren't people we should try to emulate.
Only when you have your house in order can you attempt to help others. Start with the people immediately around you. People you know and love and that know and love you. If you've ever dealt with a family member with a serious problem, you'll see how difficult for you to help them. Now imagine helping a friend, then casual acquaintance, then stranger finally a stranger on the other side of the world.
We should have humility as to what kind of impact we can have on the world and look inward to those around us where we can have the most impact. Otherwise you might as well wipe out hundreds of thousands of people and spend trillions of dollars spreading democracy in the middle east.