On Methods To Weather a Transition To A Hothouse Earth

[We Just Write]

So, CO2 levels today are at about half that the Dinosaurs experienced. Even with the massive demand to switch to renewable resources and energy, this is almost certain to stay in the atmosphere for the foreseeable future. Thus, the planet is almost certainly going to heat up and sea levels are going to rise.

Given that, what sort of things need to be done to ensure that the majority of humanity survives the coming crisis without losing access to our technological knowledge and capabilities? A reduction in the scale of the economy is acceptable, but not in the variety of different technologies humanity knows how to make. Assume that the ultrawealthy can be safely guillotined and disposed of.

 

[Zap Rowsdower]

So, CO2 levels today are at about half that the Dinosaurs experienced. Even with the massive demand to switch to renewable resources and energy, this is almost certain to stay in the atmosphere for the foreseeable future. Thus, the planet is almost certainly going to heat up and sea levels are going to rise.

Given that, what sort of things need to be done to ensure that the majority of humanity survives the coming crisis without losing access to our technological knowledge and capabilities? A reduction in the scale of the economy is acceptable, but not in the variety of different technologies humanity knows how to make. Assume that the ultrawealthy can be safely guillotined and disposed of.

Click to shrink...

The trick is figuring out carbon capture and sequestration. Triggering algal blooms to sink it to the bottom of the sea might have promise, although that's based more on cursory pop-sci than in-depth research.

 

[We Just Write]

The trick is figuring out carbon capture and sequestration. Triggering algal blooms to sink it to the bottom of the sea might have promise, although that's based more on cursory pop-sci than in-depth research.

Click to shrink...

Yeah, that might help. As would other means of putting the genie back in the bottle. On the other hand, with stuff like the methane clathrates in Siberia, greenhouse gasses are probably going to keep entering the atmosphere even if we cut all the CO2 emissions to zero right this second.

 

[Leila Hann]

Barring a new technological breakthrough in carbon sequestration, there's not much we can do to fix this besides the shit we've already known we should be doing (and not done) for decades.

So, in terms of weathering the coming changes...

The two biggest issues are going to be water resources, and coastal degradation. The former can be dealt with by doubling down on water purification and desalination technologies, in particular ways to make them cheaper and more energy efficient so they can be used by poorer populations and without needing us to dump even more fumes into the atmosphere to power them. The latter...well, there's not much you can do about rising sea levels besides moving inland.

If it makes you feel any better, the latter at least will fuck the rich as well as the poor.

 

[RRoan]

The latter...well, there's not much you can do about rising sea levels besides moving inland.

If it makes you feel any better, the latter at least will fuck the rich as well as the poor.

Click to shrink...

Build dikes. Expensive, but less expensive than abandoning major world cities.

Third-world and developing countries are fucked, though.

 

[We Just Write]

Let's see, maximum sea level rise would peak at around 80 meters, with worst-case annual rise being about a couple meters per year. Those'd be some really big dikes.

 

[RRoan]

Let's see, maximum sea level rise would peak at around 80 meters, with worst-case annual rise being about a couple meters per year. Those'd be some really big dikes.

Click to shrink...

One or two or five thousand years from now if we kept doing what we're doing, maybe.

Multiple meters per year is ridiculous fantasy.

 

[We Just Write]

One or two or five thousand years from now if we kept doing what we're doing, maybe.

Multiple meters per year is ridiculous fantasy.

Click to shrink...

There's a reason I categorized it as the worst case scenario. Chances are that yes, it will be slower than that.

 

[Zap Rowsdower]

Absolute rise is not the limiting factor on a human timescale, in terms of coastal costs. Storm surge is, along with the separate issue of saltwater intrusion of groundwater as the sea raises the water table.

 

[Whachamacallit]

A couple meters per year? I don't think anyone thinks sea level rise could happen that quickly! Multi-decadal sea level rise (or Meltwater Pulse) could result in several meters of sea level rise over the course of decades. 80 meters of sea level rise is most certainly possible, but it would probably take a bit of time to reach that since most evidence indicates that the East Antarctica Ice Sheet will probably take a long time to melt compared to Greenland and WAIS.

Still, even the more conservative sea level rise scenarios (take the middling IPCC) would still cause a lot of damage in this century alone. A thing people tend to forget is that erosion is going to eat away at a lot more land than people realize, so even marginal increases will be destructive. While it's reasonable to say that there would at least be an attempt to protect the most important cities from sea level rise, there would be plenty of property casualties.

Some parts of cities would have be sacrificed to protect the rest (you gotta put those dikes, canals, and pumps somewhere), and most settlements aren't likely to see any effort for protection other than a weak local attempt. So Atlantic City very well may be doomed for example. Also, some major cities just can't be saved, with Miami being the classic example. Even if dikes were placed for Miami, the sea would just seep right under it. Maybe it could survive as a floating city I guess?

And of course, that's not even talking about the risk of a meltwater pulse. If one starts in this century, that would be a real catastrophe, even if one only looks at it in the forms of economics.

 

[Spacehillbilly]

This is going to sound like a stupid idea, but we should build a dyke over the melted permafrosts to keep the carbon dioxide from building up.

 

[Spacehillbilly]

We can also try to drain excess water from the rising sea levels, ala the never realized Atlantropa project.

 

[RRoan]

There's a reason I categorized it as the worst case scenario. Chances are that yes, it will be slower than that.

Click to shrink...

Getting a couple of meters of sea level rise per year would require a substantial portion of earth's total insolation to be used purely for melting ice, with no inefficiencies or losses of any sort.

Like I said, ridiculous fantasy.

 

[We Just Write]

Getting a couple of meters of sea level rise per year would require a substantial portion of earth's total insolation to be used purely for melting ice, with no inefficiencies or losses of any sort.

Like I said, ridiculous fantasy.

Click to shrink...

Fair enough. I suppose I just like to over-engineer things.

 

[Quickshot0]

Well to put things with sea level rise on a more realistic footing then. It probably would help if other countries would take the Dutch advice on their undefended coastal cities more seriously. Rushing to build it afterwards is more expensive and can lead to less good implementations. Not to mention the reason for rushing all to often turns out be that some one let the city or area flood once... or many times already.

If such advice is taken seriously, then even in fairly quick sea level rise scenarios, much of the highly developed coastal areas in the world could be protected for a century or so at least I think. Which would give civilization a fair bit of time extra to think about how to resolve their coastal problems.

 

[FullNothingness]

Sea level change is likely going to be a problem... But I expect it will be a limited one.

The part I'm really worried about is changing climate rendering zones of the planet to hot to live or at least too hot or dry for practical agriculture. Once food prices start rising significantly there are going to be major issues. And once stuff like that starts happening (more) migration will kick into high gear. And the advanced nations aren't handling current levels of migration gracefully at all already. Once whole zones of the planet become uninhabitable people will move. And that is likely to mean widespread violence one way or another.

 

[We Just Write]

Sea level change is likely going to be a problem... But I expect it will be a limited one.

The part I'm really worried about is changing climate rendering zones of the planet to hot to live or at least too hot or dry for practical agriculture. Once food prices start rising significantly there are going to be major issues. And once stuff like that starts happening (more) migration will kick into high gear. And the advanced nations aren't handling current levels of migration gracefully at all already. Once whole zones of the planet become uninhabitable people will move. And that is likely to mean widespread violence one way or another.

Click to shrink...

So maybe we need to genehack crops to handle higher temperatures? Actually, maybe we should genehack humans to handle higher temperatures while we're at it.

 

[FullNothingness]

So maybe we need to genehack crops to handle higher temperatures? Actually, maybe we should genehack humans to handle higher temperatures while we're at it.

Click to shrink...

More drought and heat resistant crops might help. But there are limits on how far you can go there. Plants are ultimately still plants, you can't grow crops in a desert without ridiculous amounts of infrastructure.

Engineering people isn't viable IMO. Even leaving aside all the ethical concerns consider for the moment consider just how many people you would need to genetically engineer to help. You are looking at tens of millions or even more people you would need to alter. It can't be done unless technology comes up with a way to do that sort of modification vastly more cheaply and quickly.

 

[Baughn]

Engineering people isn't viable IMO. Even leaving aside all the ethical concerns consider for the moment consider just how many people you would need to genetically engineer to help. You are looking at tens of millions or even more people you would need to alter. It can't be done unless technology comes up with a way to do that sort of modification vastly more cheaply and quickly.

Click to shrink...

Leaving aside the ethical and engineering/cost issues, it's also biologically impossible. Human biochemistry is already running close to the upper end of the protein stability range, with only some smaller animals going slightly higher.

Your normal operating temperature is 36 to 38 degrees. Catastrophic failures set in above 41-ish, and it isn't even in principle possible to engineer protein-based biology that works much above that. The proteins would literally start to denature.

The only way to operate in environments above that temperature is sweating, which we're already well optimized for. We can survive in sixty, eighty, even a hundred degrees for a limited time. So long as the atmosphere is dry, and you have plenty of water, you won't easily overheat.

So what's the problem?

"So long as the atmosphere is dry." There's a thermodynamical limit to evaporative cooling, called the wet-bulb temperature; it's the temperature a wet thermometer reaches in the shade. At 100% relative humidity it's equal to the air temperature, but usually it's a fair bit below. It's what causes "muggy weather".

The maximum wet-bulb temperature humans can survive, under any circumstances, is in the low thirties.

Climate change is scheduled to cause massive, humid heat waves that will push it well into the forties, for instance in lowland India. Get caught in that, and if you lack AC (or ice), or there's a power failure, you will die.

 

[Vindictus]

Leaving aside the ethical and engineering/cost issues, it's also biologically impossible. Human biochemistry is already running close to the upper end of the protein stability range, with only some smaller animals going slightly higher.

Your normal operating temperature is 36 to 38 degrees. Catastrophic failures set in above 41-ish, and it isn't even in principle possible to engineer protein-based biology that works much above that. The proteins would literally start to denature.

The only way to operate in environments above that temperature is sweating, which we're already well optimized for. We can survive in sixty, eighty, even a hundred degrees for a limited time. So long as the atmosphere is dry, and you have plenty of water, you won't easily overheat.

So what's the problem?

"So long as the atmosphere is dry." There's a thermodynamical limit to evaporative cooling, called the wet-bulb temperature; it's the temperature a wet thermometer reaches in the shade. At 100% relative humidity it's equal to the air temperature, but usually it's a fair bit below. It's what causes "muggy weather".

The maximum wet-bulb temperature humans can survive, under any circumstances, is in the low thirties.

Climate change is scheduled to cause massive, humid heat waves that will push it well into the forties, for instance in lowland India. Get caught in that, and if you lack AC (or ice), or there's a power failure, you will die.

Click to shrink...

Obviously, we just need to install heat sinks into our inefficient biological frames.

On that note, we should upgrade to more efficient mechanical frames.

I mean, if we aren't going to stop the death of all organic life, it only makes sense to stop being organic lives ourselves, right?

 

[Avernus]

Getting a couple of meters of sea level rise per year would require a substantial portion of earth's total insolation to be used purely for melting ice, with no inefficiencies or losses of any sort.

Click to shrink...

It doesn't have to all melt, it just has to slide into the ocean. Solid icebergs displace seawater too.

 

[RRoan]

It doesn't have to all melt, it just has to slide into the ocean. Solid icebergs displace seawater too.

Click to shrink...

The vast majority of Antarctica's ice is in eastern Antarctica, on solid bedrock above sea level and going nowhere fast. The west Antarctic ice sheet is the one which is in serious danger, but even there a total collapse would take centuries and only result in a few meters of sea level rise.

 

[Spacehillbilly]

Im writing a letter to my representative about this.

Any suggestions?

 

[Zap Rowsdower]

Leaving aside the ethical and engineering/cost issues, it's also biologically impossible. Human biochemistry is already running close to the upper end of the protein stability range, with only some smaller animals going slightly higher.

Your normal operating temperature is 36 to 38 degrees. Catastrophic failures set in above 41-ish, and it isn't even in principle possible to engineer protein-based biology that works much above that. The proteins would literally start to denature.

The only way to operate in environments above that temperature is sweating, which we're already well optimized for. We can survive in sixty, eighty, even a hundred degrees for a limited time. So long as the atmosphere is dry, and you have plenty of water, you won't easily overheat.

So what's the problem?

"So long as the atmosphere is dry." There's a thermodynamical limit to evaporative cooling, called the wet-bulb temperature; it's the temperature a wet thermometer reaches in the shade. At 100% relative humidity it's equal to the air temperature, but usually it's a fair bit below. It's what causes "muggy weather".

The maximum wet-bulb temperature humans can survive, under any circumstances, is in the low thirties.

Climate change is scheduled to cause massive, humid heat waves that will push it well into the forties, for instance in lowland India. Get caught in that, and if you lack AC (or ice), or there's a power failure, you will die.

Click to shrink...

There is a solution, and it can be seen in fossils from the last time temperatures got this bad, in the eocene: size. The square/cube law means that the smaller you are, the more surface area per unit mass, and so the less heat is retained and the more is radiated out. There's a reason basically so many species in the eocene, from eohippus to eosimias, topped out at "medium sized dog", and it's the same reason there was so much megafauna during the opposite conditions of the pleistocene.

The problem, of course, is that reduction in human size has a rather hard limit in terms of getting the head through the birth canal, so whether we can engineer small enough kids is rather questionable.

 

[Quickshot0]

You could make longer skinnier humans instead I guess? There's limits there as well, but it at least lets you increase your surface area a bit. I think one can see something that looks a bit like this adaptation in some very hot regions of Ethiopia as well.