I think most of us would just be satisfied with rendering the Earth a lifeless husk.
If gntm thinks that inadequate I submit they may be letting the worst become the enemy of the bad.
on edit: changed he to they.
If gntm thinks that inadequate I submit they may be letting the worst become the enemy of the bad.
on edit: changed he to they.
The problems with DDT were that (1) it could last a long time before breaking down, (2) it spread much more widely in the environment than was intended, and (3) it was not narrowly targeted to only affect pests.
When you are making a pesticide that is not narrowly targeted [1], you really want it to break down fast and to not spread much beyond where you specifically apply it.
Just make a pesticide that like DDT spreads far and wide and persists, but unlike DDT make it so one of the things it kills is nitrogen fixing bacteria. That would wipe out almost all of the base of terrestrial animal food chain.
[1] You make a narrowly targeted pesticide by basing it on the hormones that control the target's life cycle. You find some specific behavior of the target, such as its "mate and die" behavior, that is triggered by a specific hormone, and make your pesticide trigger that. Then all you need to do is apply the pesticide when the insect isn't yet sexually mature or when the weather is too cold for eggs to survive, and the insects mate and die, with no offspring produced.
https://en.wikipedia.org/wiki/The_Screwfly_Solution
Same author wrote a short story about a scientist who developed a tailored virus to save the earth from ecological destruction:
https://www.lightspeedmagazine.com/fiction/last-flight-docto...
"The tape recorder they put by his bed functioned right on through, but if anybody had been around to replay it they would have found little but babbling. “Gaea Gloriatrix,” he crooned, “Gaea girl, queen . . .” At times, he was grandiose and tormented. “Our life, your death!” he yelled. “Our death would have been your death, too, no need for that, no need.”
At other times, he was accusing. “What did you do about the dinosaurs?” he demanded. “Did they annoy you? How did you fix them? Cold. Queen, you’re too cold! You came close to it this time, my girl,” he raved. And then he wept and caressed the bedclothes and was maudlin."
Though -- it's actually a lot of CO2, for starters burning absolute every last bit of fossil fuel would probably contribute to ~0.1% of the amount needed for a runaway greenhouse event.
"Recoverable" coal is about 20 times proven reserves, so burning all that would add 4000 ppm CO2. Now the total would be 4500 ppm CO2, or almost 0.5 percent! Likely to be quite unhealthy.
https://knoema.com/infographics/smsfgud/bp-world-reserves-of...
It's worth noting that the Earth's atmosphere would be incompatible with current life at various past levels of atmospheric carbon.
In the past, Earth's atmosphere was almost entirely nitrogen and carbon dioxide[1], but at some point some plucky cyanobacteria learned how to photosynthesize and convert CO2 into O2, hugely changing the contents of the atmosphere [2] and killing a large amount of life that couldn't tolerate the new order.
So if we were to burn all the fossil fuels, it's quite possible that this would cause a climate catastrophe that would kill a large majority of life on earth. But there's a decent chance that the cyanobacteria and friends would survive and, after hundreds of millions of years, restart the evolutionary process.
Note that climate catastrophes take many forms, and the "greenhouse effect" does not even necessarily have to be involved. Take ocean acidification for instance. Atmospheric carbon raises the pH level of the ocean, which can cause cascading ecological collapse.
[1] https://en.wikipedia.org/wiki/Paleoclimatology
I think it's worth noting that on this timescale, we don't have forever:
"In about one billion years, the solar luminosity will be 10% higher than at present. This will cause the atmosphere to become a "moist greenhouse", resulting in a runaway evaporation of the oceans. As a likely consequence, plate tectonics will come to an end, and with them the entire carbon cycle... Four billion years from now, the increase in the Earth's surface temperature will cause a runaway greenhouse effect, heating the surface enough to melt it. By that point, all life on the Earth will be extinct." - from https://en.wikipedia.org/wiki/Future_of_Earth
I submit that this is probably Earth's only chance at a spacefaring civilization, and therefore Earth life's only chance at escaping the planet (and thus surviving the death of the planet). If we flub it and cause a mass extinction without anything to show for it, it is the beginning of the end of Earth's story.
http://burro.case.edu/Academics/USNA229/impactfromthedeep.pd...
There doesn't seem consensus on whether Earth could truly reach a runaway greenhouse state or would rather just settle at a higher temperature. In any case, only the ecological (and consequently economic) crises and refugees problem are the ones currently living people will be affected by, but that ought to be enough to take action.
[1] https://sciencing.com/effect-temperature-rate-photosynthesis...
In addition to the greenhouse effect, the location of the continents can also have a major influence on the climate due to the influence on ocean and air currents, the albedo, weathering speed of exposed rock in the tropics and different plant cover at different latitudes etc, thus it is hard draw good comparisons (only modelling is possible, and verification is hard).
To be fair, I do not believe we are capable of life extinction on Earth. We are also not able to make the conditions on this planet worse than it is on any other planet we can reach so far. But we can cause a mass extinction easily and make life for ourselves much much harder. Our situation is so optimized for the current conditions that changes will cause great pain. (Just look at the locations of cities, or how agriculture is run.) If we developed with the climate of 500 million years ago we would be just fine with that. The problem is the fast and large change.
[0] https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_at...
PS: One more point: CO2 causes some cognitive issues in humans in concentrations above 1000 ppm, which often occurs in meeting rooms and means the windows need to be opened regularly. It's not bad, you just get a little tired and dumber... so you take a break and open the windows. Now imagine the CO2 concentration outside is 5000 ppm (currently at ~415 ppm). We did not evolve for this.
Because radiation dissipates to the distance squared, we get around 40-50% of the heating Venus does.
As a much nearer term goal, the Earth could be rendered all but sterile by removing and permanently sequestering carbon from the atmosphere to break the carbon cycle [0].
1) Direct air capture of CO2 from the atmosphere.
2) Conversion of CO2 to carbon with electrolytic hydrogen [1].
3) Reaction of carbon with silicon dioxide in an electrical furnace to form silicon carbide [2].
4) Surface storage of ever-increasing quantities of silicon carbide to end the Earth's carbon cycle and life itself.
Bulk silicon carbide is effectively inert to biological or geological decomposition under surface conditions on Earth. It can break down if subducted into high temperature regions of the mantle, so it will need a watchful eye to keep geology at bay until the sun's expansion destroys the Earth completely.
You'll need some basic clanking replicators (e.g. strictly earthbound von Neumann machines) to accomplish this. 99% of the life-elimination process can be finished in mere thousands of years. Either nuclear breeder reactors or paving the world's great deserts with solar panels can provide enough energy for the project.
Silicon carbide can also oxidize in a furnace, so human civilization must be neutralized. But if you have a fleet of von Neumann machines dedicated to eliminating life that's one of the first problems to solve anyway.
"Won't falling atmospheric CO2 trigger a new glacial maximum and greatly retard the rate at which environments can be decarbonized/sterilized, once ice cover impairs carbon cycling to the atmosphere?"
Great question!
You don't want a lot of frozen water on Earth because that will make it harder for CO2 to circulate through the atmosphere where it's easy to capture. It takes thousands of years for the ocean to fully overturn and exchange with the atmosphere under present climate conditions; there's no sense in making it even slower with sea ice. Nor is hiding soil under glacier cover a sustainable solution to the life problem. But you also don't want to leave CO2 in the atmosphere just to keep things warm and freely circulating.
Some small portion of the replicators' effort can go toward manufacturing potent non-carbon-bearing greenhouse gases such as nitrogen trifluoride or sulfur hexafluoride. They are so much more potent than CO2 that just a bit added to the atmosphere should keep the Earth comfortably warm even as CO2 becomes too scarce to support photosynthetic life.
In only 10,000 years most multicellular life can be eliminated by carbon starvation. Some remnants of life will remain deep underground and near hydrothermal vents on the ocean floor. The machines must continue to eliminate CO2 as it is emitted by natural geological processes and maintain the mountains of silicon carbide so that they remain intact into deep time. Otherwise there could be another large scale outbreak of life before the sun finishes Earth.
[0] https://www.pmel.noaa.gov/co2/story/Carbon+Cycle
[1] https://en.wikipedia.org/wiki/Bosch_reaction
[2] https://en.wikipedia.org/wiki/Silicon_carbide#Production
You're probably right. I mean, have you seen Factorio?