I am a climate scientist and geologist and think that climate, geology, and geography are incredibly interesting fields that people deserve to know more about. If you have any questions that you’ve sat with for a while, are just curious, want to know more about future or past scenarios, or even have worldbuilding questions, feel free to ask!
It depends on the size of the eruption, but I’d be pretty concerned that we aren’t prepared societally for the several years-decades long aftermath that would cause to global climate, especially because of the already difficult to predict changes brought about by human caused climate change. It would take several years at least to accurately determine the best areas to produce food, and even these would be subject to very unpredictable conditions and could fail at any time. Life would majorly suck for a while and it would likely cause massive unpredictable shifts in human migration and in geopolitics