> apparently super volcanoes are also right up there. And I don't think there is a damn thing we can do about them

I'm not sure about that.

Don't get me wrong, an example of a super-volcano is Yellowstone National Park, so I agree we can't prevent them

Rather, looking at the pandemic response and various wars, I think (most) world governments are competent enough to re-organise labour and national diets to mitigate the problems one would cause: covering farms in poly-tunnels, having "national service" that's about building/repurposing farming infrastructure rather than military function, food rationing, changes to farming laws to make sure livestock is only on land that doesn't support intensive crops, etc.