They're the disasters that spawned an entire genre of TV shows and books - a supervolcano, a nuclear war, or a massive asteroid strike that leaves the Earth a barren and post-apocalyptic wasteland.
But it turns out that while it wouldn't quite be "business as usual", Australia is pretty well-positioned to avoid our society going full Mad Max in the event of an apocolaypse.
A report published in the journal Risk Analysis examined what countries around the world were best place to survive, if not thrive, under an "abrupt sunlight reduction scenario".
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Such a situation could be caused by a nuclear winter, or an eruption by a supervolcano that dims the sun in the sky. It can lead to - depending on severity - a severe loss of food production, freezing temperatures, and mass loss of plants and wildlife.
But according to the report, Australia, along with New Zealand and other Pacific nations including Vanuatu and the Solomon Islands, have the best chance in the world of weathering such a catastrophe more-or-less intact.
Australia's massive natural resources and agricultural production meant our food buffer was "gigantic", the researchers said.
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By comparison, nations such as China, the US and France were more likely to suffer a 97 per cent loss in food production.
Australia could also remain self-sufficient in terms of energy supply, the report found, and its stability, strong health system, and well-maintained infrastructure were also in its favour.
New Zealand, by comparison, relied on trade for much of its energy, which could suffer badly in the event of a northern hemisphere left essentially non-functional in a potential wartime scenario.
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But New Zealand did have advantages over Australia, including its geography - with most of its regions relatively close to the ocean, it would be freer of any temperature extremes.
And Australia's closer military ties to the US or UK could lead to it being a target in a nuclear exchange.
The report focused on island nations, but noted that in previous analyses, Scandinavian countries had been rated among the most resilient in the world.
The researchers did include Iceland among their top potential survivors.
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Ultimately, the report advised against any nation opting to "go it alone" in such a situation, urging strong alliances and contingencies be prepared.
"Trade in food, energy, components, and expertise is needed to maximise survival chances in the face of severe climate effects and the cascading impacts across many human and ecological systems," the authors wrote.
"Collapse of technological society is possible even in locations considered most likely to survive. This may seriously impede cooperation, coordination, and resilient food production."
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