How long will the earth stay in good nick?

[FancyDarcy]

So apparently people are worried about the methane in ice leaking out. Are the consequences likely to come to life any time soon? How much time is left, a decade or two? Or is it all just a popular theory?

[SpottedKitty]

It's a bit more complicated than just "methane in ice" — the ice in question is Siberian permafrost, by definition it never thaws even in summer. Except now it's beginning to, due to changing climate. The methane locked into the ice, mostly from very slowly decomposing vegetation underneath it, is now beginning to seep out. If anything causes it to ignite... you get the big holes in Siberia that have been in the news recently.

I watched a documentary on the subject a year or so ago; the presenter and a local dug a hole in surface snow, I think it was over a Siberian lake that was frozen all the way to the bottom, and had been that way for a very, very long time. They poked a small flame on a pole into the bottom of the hole. <WHOOMP> Bye-bye eyebrows.

Incidentally, methane is a much better greenhouse gas than carbon dioxide. There's probably a lot of it in the permafrost, waiting until the frost is a lot less perma. And there's even more methane locked away in chemical compounds in near-freezing deep sea sediments; compounds that let go of their methane if they're warmed up a bit.

As for a time scale; no-one knows, yet.

[Lord Revan]

even so I pretty sure we will talking about timefare in centuries rather then decades, changes on a global scale tend to be slow and even with climate change as it is now it started in the late 19th century.

[Broomstick]

There are also marine deposits of the stuff, which cause concern.

[FancyDarcy]

hmmmm. well I hope it lasts a little longer than just a few decades.

now i've heard that it's much more difficult to "colonize" a ruined earth and establish a self-sufficient colony than say on Mars or Moon. how does that work out? i would've thought the worst earth we could make would be nowhere near as inhospitable as Moon or Mars.


Ok, this might sound a little odd, but I worry about those trumpet noises from the sky; are these really a sign of the apocalypse? What could be causing them? it's somewhat concerning because I thought it said in the Bibles that trumpet sounds were a sign of the end... wonder how they could herald the end times?

[Khaat]

now i've heard that it's much more difficult to "colonize" a ruined earth and establish a self-sufficient colony than say on Mars or Moon. how does that work out? i would've thought the worst earth we could make would be nowhere near as inhospitable as Moon or Mars.

Most of that comes down to easy availability of resources: since humans have been mining/harvesting/collecting all the "low hanging fruit", the only stuff left is in harder-to-get-to places (on Earth).

I had a discussion with a friend about a post-apocalyptic setting this last weekend: all the easy-to-reach/use iron deposits are gone. And a primitive tech-base probably couldn't harvest "leavings" of steel girders, automobiles, or bridges, since they don't have the (industrial) capacity to heat it enough to melt it. My counter was some generally-destructive process that would be pretty labor intensive and high-loss (corroding it and re-smelting), but the point stands: the "easy resources" that allowed industrial advancement historically are spent. Recolonizing a ruined Earth would require industry on a scale that, by definition, wouldn't be there anymore.

If you're hearing trumpets metaphorically, relax: think globally, act locally. Be a good steward of the Earth.

If you are hearing trumpets literally, get your ears checked, then your head.

[Broomstick]

now i've heard that it's much more difficult to "colonize" a ruined earth and establish a self-sufficient colony than say on Mars or Moon. how does that work out?

Depends on what you're looking for.

A "ruined" Earth for most instances we'd be talking about at least has an atmosphere worthy of the name, and it's probably breathable. It has liquid water. It has (probably) viable dirt to grow crops in. For base survival, Earth is the winner.

For a technological civilization - that's already been addressed. Except I'm not sure how much "low hanging fruit" there would be on the Moon given that its constituent rocks seem to be of lighter and mostly non-metallic elements.

Mars, of course, has lots of iron, hence the color, but I'm not sure how easy it would be to turn it into a useful form.

[SpottedKitty]

I had a discussion with a friend about a post-apocalyptic setting this last weekend: all the easy-to-reach/use iron deposits are gone.

Not strictly true; look up "banded iron formations". They're ancient rocks, mostly dating back to the first appearance of life that used oxygen in its metabolism. There was a lot of iron dissolved in the oceans, and this iron promptly grabbed the oxygen as it was produced, converting it into a variety of iron oxides which built up on the sea beds. (This was one of the main reasons why it took so long for more than traces of free oxygen to appear in the atmosphere; there was a lot of iron, and it grabbed the oxygen before it could accumulate.) These iron rocks used to be all over the planet, but plate tectonics dragged parts down into the mantle. The biggest chunks of what's left are in Australia and parts of North America. It's not actually all that difficult to get at, but it's messy; there's frequently a lot of ordinary rock on top, and the layers of iron oxides are quite thin, banded (hence the name) with layers of more ordinary rock, so there's a lot of waste rock involved. Even taking all this into account, though, there's a lot of iron ore just waiting to be dug up, we're not going to run out any time soon.

For another clue how much of this stuff there is, look at central Australia. That red colour, visible from orbit, and much redder than most other deserts? It's rust, iron oxides.

[Zaune]

I had a discussion with a friend about a post-apocalyptic setting this last weekend: all the easy-to-reach/use iron deposits are gone. And a primitive tech-base probably couldn't harvest "leavings" of steel girders, automobiles, or bridges, since they don't have the (industrial) capacity to heat it enough to melt it. My counter was some generally-destructive process that would be pretty labor intensive and high-loss (corroding it and re-smelting), but the point stands: the "easy resources" that allowed industrial advancement historically are spent. Recolonizing a ruined Earth would require industry on a scale that, by definition, wouldn't be there anymore.

On the other hand, though, is it actually possible to have a catastrophe that permanently and globally wipes out our technological civilisation but doesn't leave us functionally extinct? The sheer environmental damage caused by that same technological civilisation falling apart and dumping carbon, radioactive isotopes and every kind of hazardous chemical we've found a practical use for plus a few we only keep around to science the shit out of into the biosphere... Well, by the time said biosphere had unfucked itself enough to support the kind of population you need for industrial civilisation then they might actually be finding fossil fuel deposits made up of what's left of us.

[Simon_Jester]

I had a discussion with a friend about a post-apocalyptic setting this last weekend: all the easy-to-reach/use iron deposits are gone. And a primitive tech-base probably couldn't harvest "leavings" of steel girders, automobiles, or bridges, since they don't have the (industrial) capacity to heat it enough to melt it. My counter was some generally-destructive process that would be pretty labor intensive and high-loss (corroding it and re-smelting), but the point stands: the "easy resources" that allowed industrial advancement historically are spent. Recolonizing a ruined Earth would require industry on a scale that, by definition, wouldn't be there anymore.

Suffice to say that this presents a hard problem but not necessarily an insoluble one. Among other things, there are some pretty significant physical assets that are semi-permanent in that they won't "go away" for a century or more. All those highways we've built won't be fit for use as transportation for high-speed cars and trucks after decades of neglect, but they'll be a hell of a lot easier to navigate for muscle-drawn wagons or crude steam vehicles than a total howling wilderness would.

As you noted, heavily rusted masses of steel (ubiquitous throughout the world even now, let alone after 50-100 years of declined civilization) are in effect high-grade iron ore deposits just waiting around for someone to pick them up. There's copper waiting to be ripped out of walls right now, to the point where vandals tearing copper out of buildings to resell as useful scrap is a problem already, not just in some hypothetical post-apocalyptic nightmare. Similarly, things like garbage dumps contain a lot of potentially valuable or usable material.

The really big clincher is going to be fossil fuels. A lot of other issues can be worked around, but the availability of cheap, easily burned fossil fuels was a huge boon to development at the 19th and early 20th century levels, and while plenty of oil and coal are still in the ground, they're overwhelmingly in places you can't get at without a lot of very advanced, very complex machinery.

[Patroklos]

now i've heard that it's much more difficult to "colonize" a ruined earth and establish a self-sufficient colony than say on Mars or Moon. how does that work out? i would've thought the worst earth we could make would be nowhere near as inhospitable as Moon or Mars.

You heard this from very stupid people. Beyond the obvious benefit of being able to breath, which no current climate change scenario (I assume this is the type of disaster you mean given the example in the OP) even comes close to changing, you need heat to use most of the easily available resources you might find on Mars.

Good luck starting a fire of sufficient utility on a world with a 13% oxygen atmosphere and pretty much nothing that burns readily on its surface. Oh, and you have to do it indoors...

For the "resource depleted" earth worst case scenarios to work they don't just need to come up with a plausible scenario for global disorder and collapse, but also a scenario where all knowledge is lost. The trajectory of our current civilization is the way it was because there was no foreknowledge of how things worked and the resources selected at points in time were attractive based on that circumstance.

There is much of human civilization technologically speaking that you can skip, including the reliance of period important resources, if you have even a basic knowledge of future end states.

For you comparison of colonization scenarios to be relevant at all the assumption has to be there the people choosing between the Mars/Moon/Earth options have the technology and resources to not instantly suffocate on Mars or the Moon. That is a significant technological feat representing the height of current human civilization, which means they have more than enough knowledge to kick start a colony on Earth that will bypass most of the original civilization's resource demands. They will certainly be able to recycle material.

[Khaat]

I had a discussion with a friend about a post-apocalyptic setting this last weekend: all the easy-to-reach/use iron deposits are gone.

The biggest chunks of what's left are in Australia and parts of North America. It's not actually all that difficult to get at, but it's messy; there's frequently a lot of ordinary rock on top, and the layers of iron oxides are quite thin, banded (hence the name) with layers of more ordinary rock, so there's a lot of waste rock involved.

That was kind of my point: what's left would be labor-intensive for a regressed/recolonizing people to make use of. The "low hanging fruit" is gone. Sure there's something left, just like there's fuel for nuclear reactors in (enough) seawater, but how are you going to get to it, to use it? Through lots of hard work, or an industrial base that doesn't exist on a planet you have to "recolonize".

Suffice to say that this presents a hard problem but not necessarily an insoluble one.
*snip* and while plenty of oil and coal are still in the ground, they're overwhelmingly in places you can't get at without a lot of very advanced, very complex machinery.

On the other hand, though, is it actually possible to have a catastrophe that permanently and globally wipes out our technological civilisation but doesn't leave us functionally extinct? The sheer environmental damage caused by that same technological civilisation falling apart and dumping carbon, radioactive isotopes and every kind of hazardous chemical we've found a practical use for plus a few we only keep around to science the shit out of into the biosphere... Well, by the time said biosphere had unfucked itself enough to support the kind of population you need for industrial civilisation then they might actually be finding fossil fuel deposits made up of what's left of us.

OP's scenario didn't specify, but there are a number of ways that current society (and population) could collapse that don't involve nuclear exchange or open war: pandemic, heavily automated infrastructure collapse (computers catch bugs too!), etc.. I had made a list of options for my own P/A game setting/backstory, but only one was open war. Yes, the half-life of a nuclear exchange would put recovery in the tens or hundreds of thousands of years; still not long enough for current biology to become fossil fuels (but my understanding is limited.)

A number of the scenarios presented on this board recognize that a small population can't maintain a deep industrial base, merely because of the layers of intercomplexity. If you have "magic box" technology (say, a replicator), best hope you make another one before the first breaks, because odds are the folks you have with you can't make a new one "from scratch" out of what you have on-site (and no, the containers full of stuff you brought from high-tech home likely can't be replaced here, either!) And a functional understanding of quantum physics probably isn't going to do a lot of good, when you're worried about merely surviving.

[FancyDarcy]

hmmm, well I sure hope the planet doesn't spontaneously explode overnight before I've had any time to properly live on it yet :/

that would be too bad..

[Alyrium Denryle]

So apparently people are worried about the methane in ice leaking out. Are the consequences likely to come to life any time soon? How much time is left, a decade or two? Or is it all just a popular theory?

OK. Here is the realistic worst-case scenario.

Right now, we are looking at a 4 degree temperature rise in the next hundred or so years, unless we start swarm building nuclear plants and mastering commercial fusion power (that will keep us at 2 degrees). This will flood our coastal regions, melt glaciers (keep in mind how many of the great rivers of the world are fed by glacial melt and how important those are for keeping China and India alive), and cause disruption to the climate system, making agriculture...difficult. So you get mass famine and a refugee crisis that makes Syria look like a polite game of musical chairs. That is just projecting based on our emissions, last I checked. There are feedback loops in the system that could make things much much worse, but we don't know where the tipping points in the feedback loops are. Could be 4 degrees of warming, it could be 10. We're not sure. We might be able to counteract it with geoengineering, or we might not.

Our extreme northern latitudes have something called permafrost. It consists of a mix of ice and decaying vegetation, and it never freezes. It basically forms from mixtures of water and dead vegetation freezing every year and insulating the layers below from thawing. However, even though it freezes, that vegetation slowly decomposes anaerobically (without oxygen) resulting in methane, a powerful greenhouse gas (20 times more powerful than CO2 molecule for molecule). This gets trapped in the ice. Right now, we have enough warming from CO2 that the upper layers of the permafrost are starting to melt, releasing methane. Increased temperature will also speed the rate of aerobic decomposition, which releases CO2...That causes further warming, which melts more permafrost, which releases more methane. This leads to a positive feedback loop. If it gets warm enough... that is when we get into a few other problems. There are pressurized methane hydrate deposits in the deep ocean. They are only liquid because the combination of temperature and pressure keeps them that way. If those cook off, it will cause more warming.

Then there is sea ice and snow reflectance (white surfaces reflect sunlight before it gets absorbed and re-emitted as IR, which is the frequency held in by CO2 and Methane)

Now, the ocean currents that keep seawater circulating (heat, and oxygen) are driven by atmospheric heat. Too much heat, and those current slow ,stop or get submerged, which means heat does not circulate from the equator to the arctic which means that northern areas, even with climate change, become unlivable. Worse, the deep sea is starved of oxygen and dies, and heat gets trapped in the upper layers. More hurricanes are one consequence of this, but warm water also holds less oxygen... so large quantities of ocean life will suffocate.


It gets bad. Our species (if not our civilization) might survive, but... well, we really don't want to experience the Permian extinction again.

[Flagg]

To summarize what AD said: We fucked. Everything not human is fucked more.

Unless a full scale nuclear war happens triggered by water wars (most likely it would be China and India at the start, due to there being far, far, less (if any) fresh water from the Himalayas and fighting over that resource could escalate into a regional nuclear war, then pointless chest thumping by their allies would be the cause if the full scale launch of western and eastern ICBM's took place. That would make GCC moot) Sadly, if it's a limited nuclear war it may actually reduce or reverse the effects of Global Climate Change for several decades. But it's not worth the dead billions.

If you want solutions, the easiest would be solar shades launched into a "deep orbit" (to avoid space-crap) placed in strategic areas to preserve glaciers and generally reflect some sun. It's probably cheapest and they would be pretty light since you don't need them any thicker than aluminum foil (probably not even that thick) so even private space agencies could launch smaller ones.

[Raw Shark]

To summarize what AD said: We fucked. Everything not human is fucked more.

Yeah, that's about the situation unless some major positive shit happens. Part of the reason I don't want children very much. I try to be optimistic, but why bring a human into a world that dies? That's just cruel. My goal is to have as much sex and other fun before the end.

Unless a full scale nuclear war happens triggered by water wars (most likely it would be China and India at the start, due to there being far, far, less (if any) fresh water from the Himalayas and fighting over that resource could escalate into a regional nuclear war, then pointless chest thumping by their allies would be the cause if the full scale launch of western and eastern ICBM's took place. That would make GCC moot) Sadly, if it's a limited nuclear war it may actually reduce or reverse the effects of Global Climate Change for several decades. But it's not worth the dead billions.

I'm going to opine that either China or India would probably take the USA out first before staring WWIII, or y'know as the initial pawn move, just on general common sense (maybe Russia second, and somebody might fuck Israel just 'cuz), and then clean up on the other side of Asia before they get their ducks in a row. Americafreedomsparta might not have the largest population, but (not trying to brag) we're kind of the 10' bear in the room. If anybody gets nuked first, it's probably, in the service of poetic justice, us (including this guy; I live within no-living distance of two or three prime targets than I can think of in ten seconds. If the nukes start flying, I'm super extra really not even if I was a zombie permanently dead).

[Simon_Jester]

One side getting the United States on-side for the war would probably work better than pre-emptively blowing it up.

Remember, along with being the bear in the room, the US is ALSO the nuclear power with the biggest, hairiest second strike deterrent force, and it's explicitly designed to survive an atomic Pearl Harbor and hit back at an attacker. Blowing the shit out of our military as a surprise attack to soften us up so they could get the desirable commodities from their REAL enemies didn't work too well for the Japanese, and I suspect it won't work a lot better now that everyone has nukes.

I suspect the US's path to 'falling apart' in a 'climate apocalypse' scenario would be the result of a combination of factors, probably including a lot of internal political disintegration. Not something simple like "nuked to stop you from nuking us while we nuke someone else."

[Flagg]

One side getting the United States on-side for the war would probably work better than pre-emptively blowing it up.

Remember, along with being the bear in the room, the US is ALSO the nuclear power with the biggest, hairiest second strike deterrent force, and it's explicitly designed to survive an atomic Pearl Harbor and hit back at an attacker. Blowing the shit out of our military as a surprise attack to soften us up so they could get the desirable commodities from their REAL enemies didn't work too well for the Japanese, and I suspect it won't work a lot better now that everyone has nukes.

I suspect the US's path to 'falling apart' in a 'climate apocalypse' scenario would be the result of a combination of factors, probably including a lot of internal political disintegration. Not something simple like "nuked to stop you from nuking us while we nuke someone else."

Yeah I don't see someone nuking us so they can nuke someone else as being much of a likelyhood. You hit us and our boomer subs wipe you off the fucking map.

[Adam Reynolds]

On the issue of colonization of another world vs remaining on a ruined Earth, the only advantage to leaving would be in some bizarre hypothetical in which you have easy access to an inhabitable world. Which is obviously not the case in our solar system. For better or worse we are stuck with the Earth that we have.

The only advantage to going into space it that it would prevent you from screwing up Earth any worse. Which I suppose is something.

[FancyDarcy]

Is it possible for earth's more "active", fragile atmosphere to react more violently to climate change and somehow become more hostile to (known) life than the Martian atmosphere, even if only temporarily?

[Alyrium Denryle]

Is it possible for earth's more "active", fragile atmosphere to react more violently to climate change and somehow become more hostile to (known) life than the Martian atmosphere, even if only temporarily?

No. Becoming more hostile to known life would require the rarification of our atmosphere. Now, containing more sulfur, less oxygen etc? That is possible, but wont kill off even all vertebrate life. Permian Extinction is absolute worst case scenario for natural feedback loops running amok, and that would take more greenhouse gasses than we will produce for some time.

[Terralthra]

Best idea I've seen (in addition to heavy switches to nuclear, reducing emissions drastically) is to put essentially a sunshade in the L1 Earth/Sun LaGrange point. It's an established set of technologies (we already have satellites orbiting there now). The temperature rise is large, relative to climate stability, but in terms of energy balance on the planet, it's not even 1% of the surface insolation. It'd be an ambitious project, but it's 100% within our grasp, technologically, and would absolutely work to reduce the Earth's temperature.

The trick would be getting people to take emission reduction and renewable energy and pollution seriously if we implement such a stopgap.

[Simon_Jester]

Is it possible for earth's more "active", fragile atmosphere to react more violently to climate change and somehow become more hostile to (known) life than the Martian atmosphere, even if only temporarily?

No. Becoming more hostile to known life would require the rarification of our atmosphere. Now, containing more sulfur, less oxygen etc? That is possible, but wont kill off even all vertebrate life. Permian Extinction is absolute worst case scenario for natural feedback loops running amok, and that would take more greenhouse gasses than we will produce for some time.

So, no plausible chain that runs from Earth to a Venus-like atmosphere?

[LaCroix]

]So, no plausible chain that runs from Earth to a Venus-like atmosphere?

Do you consider "all supercalderae (calderii? calderas?) on our planet erupting at the same time" plausible?
Either that or a major asteroid strike causing something similar.
You'd need a lot of volcanic gas released to create a Venusian climate (95% CO2 in athmosphere, Earth pretty much 0).

Such events might ( using up a lot of the 28% oxigen to burn everything in global firestorms, and then adding a lot of volcanic gas) get us to, like, double digit percentage CO2, an most importantly, kill off most plant and agae life that might eat it up.

That would get the ball rolling to make things venusian, in time. Still no guarantee to get similar results in the end. An iceball is still more likely.

[Alyrium Denryle]

Is it possible for earth's more "active", fragile atmosphere to react more violently to climate change and somehow become more hostile to (known) life than the Martian atmosphere, even if only temporarily?

No. Becoming more hostile to known life would require the rarification of our atmosphere. Now, containing more sulfur, less oxygen etc? That is possible, but wont kill off even all vertebrate life. Permian Extinction is absolute worst case scenario for natural feedback loops running amok, and that would take more greenhouse gasses than we will produce for some time.

So, no plausible chain that runs from Earth to a Venus-like atmosphere?

Bluntly.... no. First we would have to have very very large additions to the amount of gas in our atmosphere to bring the pressure up that high. Getting that much CO2...well...where is it coming from? To get to the Permian Extinction... Siberia had to erupt for half a million years. Not a volcano in Siberia... but Siberia