[jackacid]

Writing a story and I'm struggling to settle on this...

Can be caused by something within the Earth (volcano, weather, etc), or something from space (impact meteor, supernova, etc.) The length of time it takes to wipe out life does not matter....from days/weeks to thousands of years. BUT, recovery time IS important.

I've found that it's not hard to find info on what disasters cause what kind of damage, but finding recovery times seems to be a great challenge.

I need to come up with an event that wipes out the vast majority of the planet (again, how long this takes doesn't matter), but doesn't take MILLIONS of years to recover from.

Ideally this event will wipe out 75%+ of Earth life (including most if not all human life), but takes less than 10,000 years (or so) before the planet becomes habitable again.

Of course, if this doesn't exist, that's fine too. I can always re-work my timeline.

Any ideas would be of great help, thanks!

(EDIT) PS - The only thing that needs to die here are humans....plants, animals and buildings for example can remain intact.

[James Barclay]

Sounds to me like you need some kind of hideous human-only disease. Inventing one which is unstoppable, unbelievably contagious and always fatal shouldn't be hard. Have it contracted through the air, by touch, through food, in water... and you'll wipe out most humans in whatever timescale you want. Go to stuff about the spread of pandemic flus and it'll give you an idea on how these things grow when unchecked. World Health Organisation is a good place to start.

Then it's up to you how long it takes for the disease to die away and the population to recover. You can have it touching whichever species you want. Leaves you in total control.

hope that helps
NOM

[Draxinusom]

(EDIT) PS - The only thing that needs to die here are humans....plants, animals and buildings for example can remain intact.

Can remain intact or must?

Apart from some disease/virus, how about an ice age ? Caused by nuclear winter, anomalous solar behaviour, mass volcanic activity and the fumes blocking sunlight, the temperature drops dramatically for a few (10,100,1000, 10000) years and then returns to normal. In the mean time, lots died.

Your recovery time is almost freely variable to what you like.

[Warzoo]

Another thing you can try is have some sort of chemical spread all over the world (by accident or as a weapon... perhaps the equivalent of a giant space crop duster, hah). Anyway, the chemical doesn't hurt plants or animals, but it does hurt humans. Animals get it from contaminated plants and pass it on to the animals that eat them (grass -> deer -> bear -> man); or they pass it to their babies (grass-> cow -> baby cow -> man) and on and on. What if you're a vegan? (contaminated soil -> plants -> man). The chemical is everywhere, covering all plants and infecting the seas.

The initial spraying would kill or starve most people within a few weeks. There would be greenhouses which might not be effected, but there wouldn't be enough of them to feed even a small percentage of the human race (and that's assuming humans would have the discipline to not let the mob eat it in the first week). The few that did survive, and managed to clean up enough soil to grow clean plants, would be confined to the areas they cleaned. That would limit available food, which would limit population.

Think of it as Radiation poisoning, except that no infrastructure is destroyed and you can set the half life of the chemical to whatever you want, thus giving you flexibility on how much time you want it to take for humanity to get back on their feet.

Anyway, tons of holes in that idea for sure. Just something to kick around.

[Tristis]

Mass sterilization. I think if you mess up the egg cells, even cloning won't work. I haven't checked that.

If it doesn't matter how long it takes to die off, what the heck? Just keep the little nuisances from breeding and they'll stop bothering you in a hundred years or so.

[KatG]

I was going to say cyclones, then I read that it had to be world-devastating. So I'd suggest drought. Which may very well take us out in the end. However, a drought that wiped most of us out might be countered by weather/climate changes that then restore water and the climate to support water, by technology to remove salt from sea water or discover underground water sources, etc.

[kmtolan]

Coronal discharge from the sun should do the job - just a burp. You can also have a gamma ray burst reach our star system. Look to the stars!

Kerry

[hippokrene]

I need to come up with an event that wipes out the vast majority of the planet (again, how long this takes doesn't matter), but doesn't take MILLIONS of years to recover from.

For the first 2,000 million years that lift existed, the dominant form of life was microbial mats. At that time, the atmosphere of the earth was very different. Then a chlorophyll filled life-form appeared, plants, and they began to suck up all the carbon dioxide and produce a toxic waste product, oxygen. This killed off a huge number of organisms, leaving space for the oxygen using eukaryote, which all multicellular organisms are from.

Here’s what could happen. A scientist or a random mutation creates a form of algae that takes oxygen from the ocean and produces as a waste product a different gas (You might want to grab one of the oxygen substitute gases that could conceivably be used in cellular respiration). They rapidly grow, and change the amount of various gases in the atmosphere. Large oxygen breathing organisms die out but there’s still enough oxygen for smaller animals: chimps, foxes, mice, birds, and snakes and many lizards are fine.

The planet is still completely inhabitable.

[jackacid]

Can remain intact or must?

Apart from some disease/virus, how about an ice age ? Caused by nuclear winter, anomalous solar behaviour, mass volcanic activity and the fumes blocking sunlight, the temperature drops dramatically for a few (10,100,1000, 10000) years and then returns to normal. In the mean time, lots died.

Your recovery time is almost freely variable to what you like.

Thanks to EVERYONE for great ideas.

Drax, to answer your question, no it's not important if plants/animals survive.

I basically wanna eliminate humankind, but allow for the planet to be inhabitable at a sooner than later time.

I'm trying to keep this as scientifically plausible as possible, so I want to avoid anything that will take several thousands (or millions) of years.

[Draxinusom]

Then you might go with anomalous (low) solar activity cooling the earth. Our true sun goes through cycles, about every 11 years of minimal and maximal activity. Currently we're well beyond minimal and there's still less solar activity that we're used to (significant enough to be beyond statistical error). If this keeps up, it may actually drop earth's average temperature a bit, but probably not beyond at most 1°C. For us, the sun _is_ cooler right now, there's less solar wind and less radiation than what we perceive normal.

Now you can simply use that and declare that your sun has a super-cycle ontop on this 11 year cycle of activity that causes a massive drop in temperature on your earth. You can go to a full iceage or simply to an extended cold period causing widespread famine, depending on how much impact you want to have and then end this cycle within your wanted timeline.