There are natural apocalypse like meteor strikes and super volcanoes. Then there are unnatural ones like Anthropogenic Global Warming is entirely human made. Also a nuclear war can cool things down for maybe a decade and might be as bad as a caldera explosion. Release of genetically modified life-forms that become hazardous or even dangerous should they get loose and alter once in the wild.
I could make the list much longer. But you get the idea.
There are natural apocalypse like meteor strikes and super volcanoes. Then there are unnatural ones like Anthropogenic Global Warming is entirely human made. Also a nuclear war can cool things down for maybe a decade and might be as bad as a caldera explosion. Release of genetically modified life-forms that become hazardous or even dangerous should they get loose and alter once in the wild.
I could make the list much longer. But you get the idea.