We have virus, magnetic pole shift and solar flares as the key elements of problems currently being on the radar. Unless we are blindsided, then an asteroid is unlikely, and a super-volcano would be an outside chance at the moment, but both still present, but with low odds of happening in the next 100 years. All of these will happen at some point, the question is when.
Viruses over the past 100 years have increases in intensity and coverage, only a few getting through. Solar flares are always possible, but dependent on their polarity and intensity for effect. Without having electrical equipment in the past, they are a completely unknown quantity, all that can be said being one major one that could take out a lot of systems worldwide in 163 years. In 2025 we possibly have a major peak that could be out of the ordinary based on current higher levels of radiation than normal at the present.
Pole shift is an unknown quantity but unlikely to happen for the next 30 years.
Asteroid and meteorite hits are common, but all that can be said is one super event or civilisation killer in 66 million years.
Super volcanoes are all over the world, some still not discovered. Volcanic activity in the world seems to be increasing again. All that can be said is one major event, Taupo volcano, 26,500 years ago. The previous one was 48,500 years before that, so maybe one every 37,500 years. Yellowstone seems to erupt about ever 2 million years, the last eruption estimated between 0.5 and 2.1 million years.
So, we have major virus outbreak – 104 years or 0.01
Carrington event – 166 years or 0.006
Super volcano – 27,000 years or 0.000037
Pole shift – 42,000 years or 0.000024
Civilisation killer asteroid – 66 million years or 0.000000015
Or one of these occurring every 64 years, so most people will experience at least one, possibly with a 50% chance of seeing two.