Or you could get involved in public policy. I assume there are some boffins somewhere in the US's $4 trillion dollar budget -- USDA, probably -- who are coming

Or you could get involved in public policy. I assume there are some boffins somewhere in the US's $4 trillion dollar budget -- USDA, probably -- who are coming up with plans for things like "what if wheat is decimated by a blight?" or "what if Missouri is just, all flooded?". Probably a bunch of academics at various Midwest universities, too. There are already grants and other public programs to support community gardens and local agriculture; a community garden should be the perfect place to apply permaculture.