We might regret pushing out the earth's orbit when the present interglacial period ends. (Also, careful: to push the earth's orbit further out you don't want to be pushing the earth further out directly; that will just make a more elongated orbit. You need to push mostly along the earth's direction of travel.)
Make a little Dyson swarm (maybe somewhere further in than the orbit of Mercury) to reduce how much of the sun's output reaches us in a form that can get through our atmosphere.
Apply genetic engineering to our crops, our food animals, and (at least for people in hotter regions) ourselves, to cope happily with higher temperatures. (And gradually move in away from the coasts, and learn to be less worried by hurricanes.)
Painting roofs and roads and things white (an obvious extension of the bright-white-litter idea) has actually been not-so-crazily suggested. I don't know how it compares as a solution with turning them all into solar panels in order to reduce the amount of CO2 we need to make for energy generation.
Construct lots of gigantic heatsinks, attached to the earth but stretching up above the atmosphere.
Construct lots of gigantic heatsinks, attached to the earth but stretching up above the atmosphere.
Wouldn't the heatsinks need to have very high temperature conductivity? Do we have suitable materials today? Are we talking about mountain-masses of superconductors?
| Wouldn't the heatsinks need to have very high temperature conductivity?
I don't think so. If you were to build /very tall/ tubes arching up into the upper atmosphere and cycle water through them (warm water up, cooling, and them travelling back down the other side of the arch), you could easily make them out of insulated concrete and still have to worry about freezing rather than lack of cooling. Of course, the problem then becomes what material can build this sort of structure, balancing height with throughput to prevent freezing.
But over long time periods, I think that you would also have to worry about the heat sinks evaporating the upper levels of the atmosphere.
If you transfer the heat to the atmosphere, it won't leave the Earth+atmosphere system, so the net effect will be zero. To actually cool the earth, you'd need to heat the atmosphere enough to make parts of it escape Earth's gravity. Aside from problematic effects on weather, this would be really hard because the upper atmosphere is very thin and so has low heat capacity and low heat conductance.
I was thinking about direct-radiation heatsinks: the inner part made of super-heat-conductive material that transports heat from ground level to a huge radiator fan in outer space, insulated by an outer layer on the way up (otherwise you lose all the heat to the atmosphere). But it would have to be both superconducting and very, very large.
Also, the cooling effect would be localized at the bottom end, so what would you stick it into? A volcano?
If you transfer the heat to the atmosphere, it won't leave the Earth+atmosphere system, so the net effect will be zero. To actually cool the earth, you'd need to heat the atmosphere enough to make parts of it escape Earth's gravity.
Depends how high you send the heat, I would've thought...? If you ferry the heat above the current effective emission-to-space height (the mesosphere should suffice), you warm that high-up air and raise the effective emission-to-space height. Assuming a fixed lapse rate, a cooler surface temperature follows.
I'm a mad scientist, not a real one. I can't make a complex model that predicts the effects of heating up the mesosphere by a degree in terms of changes in both outgoing heat radiation, reflection and absorption of sunlight, etc. I can only make a very simple model of radiating directly into space from a really, really, really big mad space radiator.
So you may well be right; I don't know.
Fair enough, haha. I figured there was a non-trivial chance you were right and I was wrong, because it's been years since I studied this stuff systematically and my memory of it isn't great.
Allow me to draw your attention to the first word in the title of the thing we're commenting on.
Yes, I think they would need to conduct well. I don't think they'd need to be superconductors. I have made no attempt to do the calculations that would be needed to figure out what would actually be needed.
But are you thinking about direct radiation at the upper end, or evaporating water into outer space with Earth-escape velocity, or something else? See also my other comment.
I was thinking direct radiation, and assuming that either (1) they go deep as well as high, cooling down the magma or something, or (2) we plug them into some kind of huge mesh of highly-heat-conductive stuff all over the earth, or most likely (3) we just let the wind do its job: if some region is being cooled relative to the surrounding region, you'll get winds blowing that will equalize the temperature somewhat.
But, once again: crazy ideas.
We should beware solutions we can't easily reverse or fine-tune in the future. The perfect solution would combine powerful output (cool the earth by 1 degree in a few years) with rapid fine tuning (we realize that wasn't a good idea and want to heat it up again by 0.5 degrees in the next year).
Here are some plausible rapid-response mad science ideas:
Swarm of small solar sails around the Earth, directly controlled like other satellites, which can fold or rotate on edge to let in more sunlight as required. Use them to effectively shorten or dim each day. Powered by sunlight and in unstable orbits so that when each sat fails, it escapes the Earth's gravity, to avoid creating more space debris in orbit.
Gene-engineer rapidly growing colonies of small (plankton-like) mollusks floating on the ocean surface. Individuals have heavy shells counterbalanced by floating aids (e.g. internal airsacs). After adults spawn, they die and sink; turnover is so rapid that most of them reach the ocean bottom uneaten, sequestering carbon. Keep the engineered plankton eater in reserve.
Seed the upper atmosphere with particulate matter to create a short-lasting global cooling effect similar to a large volcanic eruption.
I think it's fair to say that the impact on the ocean of such huge numbers of mollusks would be disastrous.
As for simulating a volcanic eruption, it would have an unpredictable effect on plant and animal life, possibly making global warming much worse once the clouds dissipated.
The solar sail idea is interesting but there is a large potential for abuse.
While we're meta, perhaps a better placement for this would be in a new Crazy Idea thread. The last one was quite popular.
Don't try to slow the change or stabilize the environment - instead get better at adaptation.
If we live in the sea anyway, rising sea levels aren't harmful. If we (and our main food supplies) can survive in a range of temperatures, we do so rather than trying to control the temperatures. As an added benefit, if we're more adaptable, it likely makes it way easier to colonize (by having to terraform a bit less) other planets.
hey, you said "crazy". Note that this probably shouldn't be either/or, it could be in parallel with stabilizing/controlling the environment.
Plant trees. I wonder why this is not incentivized more, would be the ideal low-tech way to sequester CO2 and at the same time improve the landscape.
Most sources I've read suggest that planting even very large numbers of trees would not do much to offset global warming, as mature forests have very little net CO2 sequestration effect. I've also read that the heating caused by the increased albedo of tree leaves offsets even the small gains from this one-time absorption.
Intuitively, it's fairly easy to see why any scheme for removing CO2 from the atmosphere is doomed to failure -- the concentration of CO2 in the atmosphere is fairly low and you're working against entropy to remove it. This leads to very high energy consumption per unit mass of CO2 (far, far higher than the energy extracted from burning the fuel which created the CO2) which pretty much offsets any gains that you obtained by removing the CO2. The key is not to put CO2 there in the first place.
I'd love to be proven wrong about the argument to plant trees, as I'd personally love to see more trees around.
Here's a crazy thought: plant parks, collect leaves in the fall, bioleach metals like germanium and gallium from them using chemolithotrophic bacteria (maybe after burning them and using the heat for energy, and the CO2 from burning can go to liquid cultures producing methane or something).
mature forests have very little net CO2 sequestration effect
Planting trees in forests won't make much difference. Planting trees in barren lands probably will make a difference, no?
[In Kyiv] the relevant authorities seem to find it more profitable to plant trees yearly than to nurture them into growth, and other people just see trees die and shrug thinking, so they don't grow.
Increase the rate at which lower layers of the ocean exchanges heat with the upper layers (and thus the atmosphere). The rate at which the earth is differentially absorbing heat due to AGW is small compared to the total heat capacity of the ocean - based on current rates, we'll get about one degree of warming in 300 years if the full heat capacity of the ocean is brought into play.
Life in the ocean depends on maintaining heat gradients. There's a term for when the deeper layers of the ocean start mixing with warm surface and coastal waters - "algal bloom". Algal blooms are dangerous and usually wind up killing a large amount of marine life. Among other things, this could cause global warming to become much worse.
Nuclear explosions inside supervolcanos could result in temporary volcanic winter and stop runaway global warming The same could be done by large fires in forests in taiga in Siberia.
But injecting water in the upper stratosphere may be cheapest solution as it will result in small but reflective ice clouds.
I doubt you could set off a supervolcano with such a method, but if you did, you would have a lot more to worry about than global warming.
It may be smaller volcano like Pinatubo or remote one. But the main thing is urgency. If we have runaway global warming starting from methane release, any method is good.
Super crazy: nuclear decontamination. Get rid of 90% of the humans, let the remaining 10% live.
Build a giant air conditioner in space and point it towards the Earth.
(Hey, it's just as plausible as expanding the orbit of the entire planet...)
Expanding the orbit of the Earth works under the known laws of physics but wouldn't be practically doable at all. A giant air conditioner wouldn't work for simple physics reasons.
Why wouldn't a giant AC work? Admittedly, you'd need to connect it to the Earth, not just "point it" at us. But an AC is basically a system that uses energy to move heat around; the trick is building one that puts the warm-air exhaust outside the lower atmosphere and gives it escape velocity.
For instance, as long as we're talking mad science, if we could build a space elevator with a big pool of water at the upper end as its counterbalance, cooled by evaporating into space (and maybe by contact with the upper atmosphere?), with a series of tubes connecting the pool with the sea below, then we could run an AC cycle: send warm seawater up, get almost-freezing water down. Of course we'd need a huge throughput to affect global temperature, but the principle is sound :-)
I agree that global warming is a problem right now with storms and flooding but does that hold in the looong run? I mean earth has apparently been cooling down since millions of years and the biosphere could benefit from some temperature increase, or do I read this wrong?:
https://commons.wikimedia.org/wiki/File:65_Myr_Climate_Change.png
(yes that might be looking into the future/past too far, but we are in a crazy idea thread, or not?)
Rate of change is the big thing, not necessarily absolute level.
The closest analog for what's going on now and will probably continue to go on for ~100,000 years is the Paleocene-Eocene thermal maximum (PETM) https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum . Though we may be altering the atmosphere up to two orders of magnitude faster than that one did.
Mine was to work tax policy to incentivize companies to make all their packaging shiny and white, incentivize people to litter, and disincentivize everybody from recycling.
My friend's was to use a giant rocket to push the earth farther away from the sun