This question randomly popped into my head during work today (yeah, it was a bad day, lol.)
Let’s say some higher-being reigned down from the heavens tomorrow, and took instant mind control over the whole human species. The only thing on this higher-being’s mind is wiping out all life on earth (macro & microbiotic), in order to wipe the Earth’s slate clean. By controlling humans he’s gonna try his damnest to use us to reach his goal.
If we REALLY dedicated ourselves to destroying our planet’s entire biosphere, how close could we come? I’m assuming launching all US/USSR nukes would pretty much destroy all land life, through nuclear winter/atomic explosions.
At the same time, I realize there’s deep sea volcanoes, mammoth caves, etc. If we REALLY tried, could we reduce Earth back to zero biomass?
(I’m talking full out eco-assault, dumping silo’s of bleach, , hydrochloric acid, all petro-chemicals, every bio-chemical in storage, etc.)
In my WAG, it would take centuries of concerted global effort and carefull planning. The difficult part would be keeping enough humans alive to keep following the global extermination plan, until the job was completely done. If you kill off too many humans from the start, you reduce the effectiveness of the exterminators - that’s why you wouldn’t want to start off with nuclear weapons or anything like that that might create a global winter. Instead you’d probably want to start off with the oceans - draining them and shooting the water off into space.
Very unlikely, at least in a reasonable time frame. Life in the form of microbes extends deep beneath the surface, perhaps more than a mile. And life in general is just too widespread and adaptable. We could do a lot of damage, but I doubt we could destroy the biosphere.
Now, it would be another matter if the omnicidal entity was willing to wait for a few decades; if we focused on it we could probably develop the technology to reach the asteroid belt and divert something big enough to do the job ( by rendering the Earth’s crust molten, for example ).
Now, are these aliens just wanting the rock, or do they want the landmasses/rivers in place? Because dropping the Moon onto the Earth would do a good job of it.
Otherwise, you’d want to start with dumping defoliant into the world’s oceans to kill off all the plankton. There goes a major source of oxygen and food for the earth, the rest should be nuclear fallout. Heck, at that rate even some smaller asteroids (say, a mile across) dropped into the oceans would help with the genocide via tsunamis. Ooo or even dropping one into Yellowstone! The blast and ash alone would wipe out a quarter of a hemisphere, easily.
We could deflect an asteriod so it would impact the Earth and destroy all surface life. Recent discoveries of life miles underground would seem impossible to get at so the answer to the OP is no. You would have to make the Earth molten down to the crust and this is beyond human potential.
If we had the kind of power it would take to drop the Moon onto the Earth, we wouldn’t need to do so to kill all life on Earth. We could just haul off and do it directly, and without much effort either.
Do we want to use actual poisons into the oceans to kill the plankton, or should we go with biological agents (granted, I don’t think anything’s been specifically designed for ocean-area denial), or radiological warfare? Nuking the oceans might be less efficient than building new reactors dedicated solely to contaminating them.
Still, good luck killing every last damn microbe on the planet, though. Realistically, the asteroid route’s probably the best way to go—and no screwing around with it, either. The last extinction event caused by an asteroid impact didn’t finish the job, after all.
I recall one of my science teachers telling me that during the Vietnam war, we had manufactured enough Agent Orange to completely defoliate the world’s oceans if we’d dumped it all into said ocean. Granted I can’t find any other cites for this so take it with a grain of salt.
Anyways, this all depends on how quickly we want to destroy the earth. Nuclear bombs and asteroids will certainly do a bang-up job of it (heh) but some life could still exist afterwards, if only at the cellular level. If we had Levular Mandamus around, he could just make the earth’s crust radioactive for us with a nuclear intensifier and that would definitely kill everything.
… and now I just realized I’ve been looking up ways to destroy the earth on the company computer. sweeet.
We couldn’t even make that much of a dent with the entire world’s nuclear arsenal. Figures say that there are about 20,000 warheads between all the nuclear powers. A larger warhead would wipe out all life in a fairly small radius, on the order of a few miles. Generously, that arsenal could wipe out several hundred thousand square miles of the surface of the earth – and that’s barely a dent in the 60 million square miles of land mass. The ensuing global winter would make life very unpleasant for big plants and animals, and there might be another mass extinction, but there’s so much life that wouldn’t even notice. Deep sea and underground communities would be completely untouched.
As to the giant asteroid option, you’d have to try very hard to kill off every microbe buried deep underground. Early in the Earth’s history, there was a period called the late heavy bombardment which left enough of the earth molten at any given time that we don’t see large rock formations dating before that time. I recently saw a paper (abstract here) that suggests life could have even survived through that, buried deep underground in water formations. If we wanted to kill off all life, we’d have to pretty much melt the entire crust of the earth. And avoid sending off any ejecta, which might carry off a few bacteria to eventually recolonize.
What about Venus: could we replicate its crazy-ass greenhouse effect? Seems to me that if we could get the planet’s temperatures up into the 800’s, that’d eventually do for everything.
That’d probably be effective and relatively easy. However, even Venus has a 10 km thick band in the atmosphere with temperatures and pressures that are roughly suitable for known life. If we did that to earth, there’s a chance that extremophiles would find a place to live in or above the cloud layer, especially since the process would be very slow.
There may also be microbial communities that live in our atmosphere right now (bacteria have been found, but it’s unknown if they were just blown there randomly or actually live there), and these might be untouched.
This must have been brought up in those “How can I destroy the moon?” threads, but what would it take to crash the Moon into the Earth? Here’s what I’m thinking:
you undertake a monumental mapping expedition of the solar system, to track all objects of a significant size, and determine their orbits
you then run models to see how you could nudge smaller asteroids to nudge bigger asteroids to eventually nudge (probably via gravity, not impact) the moon until it crashes into the Earth
This would take millions of years to do, but it seems like it would be within the realm of current technology.
(Sorry–I did just read Arthur C. Clarke’s Sunstorm, in which a race of ancient aliens decide to destroy humanity by shooting a Jovian planet into the Sun, which, thousands of years later, produces a massive solar flare/CME that would incinerate surface life and strip the atmosphere. But they get the Jovian moving by executing this sort of complex billiard shot with a tiny asteroid, which moves a larger asteroid, etc.)
When I ran an environmental testing lab, we would often do biological remediation studies for contaminated soil. As a part of these studies, we would run a killed-control, which would be a sample of soil that we added various chemicals to, in an effort to eliminate any microbial activity. Even in the lab, we never got microbial activity to zero - we were simply happy with really really low activity.
Extrapolating to the entire planet - I’m gonna go with “No”.
This is in one of Isaac Asimov’s popular science books from when nuclear war was the Great Fear. Unless you demolish it, it’s practically impossible to destroy life although there might not be time for what was left to evolve into anything much more elaborate than a jellyfish before the sun does its own Earth destruction.
Since that was written it’s got harder to destroy life because more extremophiles and bacteria living deep underground have been found. You have to kill stuff off that lives a miles down around superheated sulfur springs in ocean trenches, bacteria that live in ice, some that are at home down volcanic fissures. There is a theory that life started there because the UV and lightning that looked promissing in for putting amino acids together turns out to be just as good at demolishing anything more complicate.
Then there’s the likelihood that after life evolved, the planet froze solid for millions of years - Snowball Earth. Even if you boot the planet out of the solar system there is enough internal heat to keep some of those extremophiles going. In about 5 billion years I think, the sun will go red giant and first fry it, then engulf it.
Bigger life forms have been extinguished so regularly that some think that it’s connected with the system passing through a particularly ‘dirty’ part of the galaxy. The dinosaurs are the best known but there have been bigger ones and smaller ones. We may have added to the effects of the last one about 13,000 years ago - mammoths and that sort of thing.
One thing about extremophiles is that it makes the chances of life, Jim, but not as we know it a lot more likely. I wouldn’t be surprised if there’s some sort of life somewhere on every planet except maybe Mercury. Jupiter doesn’t seem to give off enough heat as it should, so maybe deep down it’s hot. So there could be things in the clouds.
I think humanity would struggle even to eliminate all life from e.g. the island of Manhattan, never mind the whole planet. Trying to set up and maintain a completely sterile environment even in a purpose-designed building is pretty challenging. In the open it would be horribly difficult. Even without taking microbes into consideration, imagine trying to eliminate cockroaches, ants and flies on a planetary basis. Not easy.
sweeet.