History ApocalypseHow / Class4

* ''VideoGame/FateGrandOrder'' has one of these in the backstory of the British Lostbelt. In Proper Human History, the alien giant Sefar arrived on Earth and caused a Class 2 apocalypse before ultimately being stopped by a PrecursorHero wielding {{Excalibur}}. However, in this Lostbelt, [[ForWantOfANail the faeries that were responsible for forging Excalibur opted to slack off instead]], which allowed Sefar to rage across the planet unimpeded. By the time they woke up, the faeries found that the surface of the planet was so thoroughly destroyed that all that remained was an endless ocean, while humanity and the gods (except one) were all extinct. This laid the groundwork for TheFairFolk to become the dominant species in that particular Lostbelt, rather than humans.

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* ''Alien Earth'' by Creator/MeganLindholm, in which a large group of Humans were rescued by aliens, just prior to the total collapse of Earth's ecosystem. What's left is mostly inedible to these humans, being mostly ground hugging bushes.

* In ''The Green Gods'', massive amounts of climate change caused plants to evolve sapience and begin taking over the world. Many animals, including humans, are on the brink of extinction.

'''Charlene Sinclair:''' A little? Your stupid spray killed all plant life!\\

* The ''Series/{{Creepshow}}'' episode [[Recap/CreepshowS1E1GrayMatter Gray Matter]] ends with Timmy’s drunken, widowed father Richie having mutated into a self-duplicating BlobMonster, with the heavy implication that he and his spawn, with their voracious bloodthirst, will bring about mass extinction in just ''six days''.

** The Cretaceous-Paleogene (earlier known as Cretaceous-Tertiary) Extinction is the most famous. Probably caused by an asteroid impact though climate change and mass volcanic eruptions may have also played a role, it killed 75% of all species, including the non-avian Dinosaurs, large marine reptiles, and pterosaurs.

* There were rumors of a close call during the 1990's when a German biotech company created a genetically modified root bacterium called K. planticola (since reclassified as R. planticola) that was supposed to increase the rate at which plant life decomposed into ethanol. Some researchers at the time claimed that they found in a test that the amount of ethanol produced would be fatal to almost every plant on Earth if the bacterium ended up in the wild. For that reason they published a paper, and thanks to that paper the USFDA stopped approving field tests with the modified strain of the bacterium. It would later turn out that the ethanol concentration was too low to be a significant threat to plantlife, that the research was not in fact published (or apparently even submitted for peer review), that the USFDA has not been approving such field tests at all, and that the modified bacteria may not have been viable in the wild anyway (let alone able to spread globally). The researchers have retracted their claims and publicly apologized, but the myth persists.

* ''WebOriginal/{{Serina}}'': The mass extinction separating the Thermocene and Pangaeacene periods sees ''99%'' of all life wiped out by runaway global warming and ocean hypoxia, leaving only a small sampling of species in one habitable zone to repopulate the entirety of the world.

** ''VideoGame/Splatoon2: Octo Expansion'' ends with the player character and their allies having to prevent one of these. [[spoiler:Commander Tartar, a human-made AI created during humanity's last days with the intention to [[FlingALightIntoTheFuture pass humanity's knowledge to the next dominant species]], decides that none of the various species that have emerged are deserving of it. As such, they aim to turn every creature on the continent into primordial ooze in hopes that the next round of sapient life meets their standards.]]

* ''Fiery Tail'' from ''Literature/HardaHorda'' antology is a near-textbook case of a mass extinction event caused first by [[ColonyDrop an entire swarm of asteroids hitting Earth]], and then the resulting ice age wiping out most of the things that managed to survive the impact event. In the unspecified future, when human survivors return from their [[TheArk Space Arks]] to resettle the planet, the biggest mammals on the surface are mouse-like rodents, and for all intents and purposes, Earth is a virgin planet without a single trace of anything even resembling civilisation. The story toys with the idea that someone might have survived, but they didn't find from orbital surveys anything that suggests even traces of permanent human settlements, implying humanity on Earth died out entirely, if not thanks to the impact event, then the following ice age.

* In ''VideoGame/SolatoroboRedTheHunter'', [[spoiler:[[BigBad Baion]] plans to use Tartaros to summon all other Juno for them to initiate the order of CODA upon the floating islands of the world (and for Tartaros specifically, the Shepherd Republic), which would result in them being brought back down to Earth and all their inhabitants being fried to death as a result of passing through the Plasma Cloud Sea.]]

* ''Film/AvengersAgeOfUltron'': Ultron intends to inflict an extinction event on the Earth, first by launching all nuclear bombs (what remained of Jarvis blocked him, and then Vision took Ultron off the internet to be sure), and ultimately [[spoiler:turning Sokovia into a [[UsefulNotes/{{Dinosaurs}} Chicxulub]]-like impactor for a ColonyDrop]]. He at first indicates he wants to push humanity to evolve and improve, but his reasoning is InsaneTrollLogic at best with his fractured mindset. Friday states when Ultron is enacting his plan that the blast will likely wipe out all human life around the world, and after losing Vision, Ultron implies he'll probably try to inflict a ApocalypseHow/Class5 so that he's the only thing left alive.
* ''Film/TheColony2013'': Overall, the Earth's biosphere has technically suffered this due to the GlacialApocalypse, with the human survivors growing vegetable plants and keeping livestock in their underground shelters. But it's not far off from being a ApocalypseHow/Class5: nothing is alive or capable of growing on the planet's perpetually-frozen surface.

* Sergej Luk'yanenko's ''Линия Грёз'', set in the ''VideoGame/MasterOfOrion'' universe, describes the destruction of the Sakras: the human Empire went for planet-wide meson bombardments on all planets that belonged to the Sakras race or were about to be conquered by them. Technically a Class 6 for those Sakras on the receiving end, the bombardment burns the atmosphere and boils the oceans. Several decades later a human refugee remarks that there is hope for her homeworld -- the oceans are about to stop boiling and the planet might be repopulated. The genocide of an entire race is unique in the books, and frowned upon by other races in the games, but repopulating and terraforming planets which were previously rendered sterile is par for the course. It is possible to win the game by becoming the only remaining sentient species.
* The conclusion of Dougal Dixon's ''Literature/ManAfterMan'' finds the Earth almost totally stripped of life by the evolved, no-longer-recognizable descendents of human space colonists. Its contaminated atmosphere no longer supports any organisms, and only a handful of native species survive, clinging to deep-sea hydrothermal vents.

->'''Earl Sinclair''': Maybe we went a little overboard with the poison.\\
'''Charlene Sinclair''': A little? Your stupid spray killed all plant life!\\
'''Earl''': Hey, what are you complaining about? You never liked salads anyway.\\
'''Robbie Sinclair''': You've destroyed the global food chain! No plants means no food at all!

* The [[ShowWithinAShow Fimbulwinter Game]], played out at Dream Park in ''Literature/TheBarsoomProject'', depicts the near-total freezing of the planet by a crazed Cabal of Inuit sorcerers. Only Arctic natives and organisms have any hope of surviving, and it's hinted that the Cabal's rituals may have overdone it, potentially pushing even these into extinction (and this example into Class 5).