perennial money

A perennial money supply?! How could we spend $500, 000 on a permaculture project to 'save the world' such that the project replenishes itself with $500 000 more every X number of years, so that we will always have a 'save the world' fund?! Paul, Katie and Jay continue to ruminate on this topic in podcast #646.

https://permies.com/wiki/229814/Podcast-Struggling-big-spend-Part#1983853

Do you have any ideas?!

Looks like we're all a bit short of ideas.
The trouble is that money is just a means to an end. Sometimes it is easier to think about achieving the end without the filthy money. Generally you have to add value - like make something and sell it - to make money.
When I heard this scheme first, I wondered about subsidised/extra pdc places. These courses seem to me to be quite expensive, although I know they do cost no more than people do spend on holidays for example. So the idea is that there is an extra place that costs say three quarters the price, as a result you get a bit of money towards funding the next subsidised place plus a permaculture trained person, that would not have otherwise been enabled that quickly, to spread the word. Obviously the actual level of subsidy would be dependent on the frequency of courses and how expensive the cost of an additional person would be.