Set up a trust to invest the money, from the compounding returns, use a sustainable portion of the dividends to fund a cause you believe will help change the world. Be very explicit to the trust managers as to the long term instructions of the trust.
With compound market returns the million dollars could be worth $40 million in 50 years and would be distributing af a sustainable 3% dividend, 1.2 million a year to a cause you believe in.
I think spending all of it on feeding people who are starving. You could keep a lot of people alive on a million, even if it was just for long enough to give them a second chance on their own. And even if that second chance failed, then at least all of the goodness of those people would have more time to be in the world.
I'm generally against the idea of planting as many trees as possible.
Trees are not very good carbon sinks because they decompose and burn. Also, there are also some ecological communities where adding trees makes the land a worse carbon sink.
Avoiding cutting down forests to build suburbs is something I can certainly get behind though.
According to Rutger Bregman: just give it away to people who don't have it.
