Ice: The Penultimate Frontier

Space may be The Final Frontier, but Colonizing Icebergs is the Rational Priority

Since SpaceX developed Reusable Launch vehicles there has been a lot of excitement about escaping from the problems of Earth and settling other planets like Mars. People are excited about Space and they are excited about creating a new frontier - with Network States, with a Martian Republic, with Charter cities and even with more conventional seasteads. However I am here to make the case that almost all of that effort is irrational because there is a vastly superior option right here on Earth that everyone is overlooking: floating ice islands.

   

  

“There is no second Earth“

Environmentalists are fond of saying that “There is no second Earth“. They are wrong! Here’s why:

There is an entire second Earth right here on Earth.

Second Earth is a waterworld. It’s the vast Pacific Ocean that covers half the planet. This is both a benefit and a detriment - the major detriment of a waterworld is that there’s no solid surface for us to build on. But apart from that one thing, Second Earth is perfect. It’s very, very cheap to send cargo to since ocean transport is extremely cheap, it has the right atmosphere, the right temperatures, etc.

Some readers may not be familiar with just how crushingly expensive it is to send stuff to other planets. A 2009 Study estimated the costs of a Lunar base at $35bn plus $7bn per year in upkeep costs - and that’s a base for just 4 people, with a liveable area probably in the range of 30m² to 200m². The ISS has a floor area of about 150m², and it costs $3bn per year in upkeep and transport costs for about 6-7 people. The initial cost for the ISS was about $150bn though with SpaceX launch prices that could be cut down by a very large factor; Starship promises launch costs of about $1M per ton in expendable mode and perhaps $100k per ton in reusable mode, though this doesn’t exist yet. And that is to Low Earth Orbit - getting to the Lunar Surface or the Martian Surface is going to be another order of magnitude in cost, though right now neither is possible at any kind of bulk rate and trips to the surface of other worlds are dangerous, one-off rides on custom vehicles.

You might think that $100k per ton is cheap. But by the standards of ocean transport, it is extremely expensive. The cost per ton for shipping bulk goods halfway around the world is about $25 per ton. That’s about 50,000 times cheaper than the cheapest current launch to Low Earth Orbit (Falcon Heavy, $1.5M per ton), and probably about 200,000 times cheaper than the cheapest current price to get to High Mars Orbit, never mind The Martian Surface or The Lunar Surface.

So, Waterworld Earth is 200,000 times cheaper to get to than Mars. There’s an existing and highly mature fleet of ships to transport stuff there. If you can even think about colonizing Mars, you want to try really hard to colonize Waterworld Earth first.

But is that possible? How do you make new land on the oceans?

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Enter ice.

Conveniently, Water is very easily formed into a solid! It’s not the best solid thing in the world, but it is solid. In times past, we even considered making a massive unsinkable aircraft carrier out of wood-pulp-reinforced ice (Project Habakkuk).

But Project Habakkuk-style ice-ships are too small. A single huge ship out in the ocean lacks the scale to be a viable nation. We want something bigger. Much bigger! At a minimum we want 300 square kilometers, about half the size of London. And we want it to be thick enough that anything we do on the surface and any weather doesn’t stand much chance of breaking our new ice-stead, so it should ideally be hundreds of meters thick.

Fortunately, nature just sort of naturally makes these - super-large icebergs break off from the ice shelves in the Antarctic all the time. Iceberg A23a has a surface area of 4,000 km², for example, and it started off with a thickness of 500 meters.

 

 

But don’t icebergs melt?

Here’s my key insight:

Preventing a large iceberg from melting is absurdly cheap per unit area compared to just about any other way of making new land.

Space colonization on Mars costs hundreds of billions of dollars for a colony the size of a large apartment. Reclaiming land in shallow seas risks sovereignty disputes and in deep seas it requires large amounts of material or just the right type of shallow shoal which will have a limited area. Building a free-floating platform like an oil rig would not constitute a solid foundation and it would move up and down with the waves, and in any case would consume a large amount of quite expensive specialized concrete and other materials on a per-unit-area basis, especially if you want it to last for hundreds of years or more. Though I have to admit that just building a lot of floating oil-rig-type structures is also a far better deal than anything to do with space!

Ok, but how do you prevent an iceberg from melting? Easy - you insulate it as cheaply as possible. I have some ideas about how you might do this, but I am probably not quite able to pick the most optimal design on my first attempt. Still, we can at least give some lower bounds on how easy this should be.

One idea for the bottom of the iceberg is to erect a grid of airtight barriers on the bottom of the berg, with cells a few dozen meters wide and a few meters tall and blow air bubbles into them. Finally you could insert some more layers of very thin plastic or some other extremely cheap & sparse material into those air pockets to break up convection cells. Lots of floating plastic balls would do it, for example, and they can probably be mass-produced in huge quantities for tiny costs. The shade balls pictured here are a bit expensive at 36¢ each, but I think we could make something cheaper than that.

Air is a great insulator and it is free (though you would have to compress it to get it down there). One square kilometer times 2 meters requires 1 million cubic meters of compressed air, which costs a minimum of 600 Gigajoules of energy to compress to 50 bar. With an onsite compression plant running at say 10MW, you can compress that much air in 16 hours. That’s super cheap, and your costs are probably dominated by the cost of some plastic sheeting and underwater operations to install it.

An alternative to a free air layer is just to shove lots of air-filled particles or balls down there with upside-down fences to contain them horizontally. This may be somewhat more expensive but it avoids the failure mode of the air finding a way to escape upwards or sideways. Multiple different sizes of particles can be used to exclude almost all of the water, then a final layer of something like plastic can be placed on the bottom to prevent bulk movement of water or particles escaping. The thermal conductivity of this layer will be close to that of air and the remaining water will freeze from the top down over time, creating a sort of ice-air matrix that’s mechanically strong and has a low thermal conductivity.

Finally you can simply use a thin layer of plastic to trap a large layer of water underneath your air or bubble insulation. This water will get cold but it will not be blown away by currents or fall due to gravity. You can even have multiple thin plastic layers that each trap a layer of water on the underside of the iceberg, using water itself as an insulator. Surprisingly, ice conducts heat about 4 times better than water (assuming that the water is not moving and convecting heat in!) so trapped layers of water are a decent insulator

We can calculate the heat leak per m² assuming that there’s a 2-meter thick layer of a 95% air/5% ice with a 5-meter thick layer of trapped water underneath it and warm ocean water at say 10°C underneath that, separated by an infinitesimally thin plastic sheet and also with sufficient internal plastic layers that we can neglect convection in the trapped water layer. The ice/air mix has a thermal conductivity of 0.13 W/Km and the water has a thermal conductivity of 0.54 W/Km, so on a per square meter basis they let through 0.065 W/K and 0.108 W/K respectively. Adding these using the harmonic mean gets you a combined thermal conductance of 0.041 W/K per square meter. We will assume that the bottom of the solid ice is close to melting at -1°C with water at 10°C, so the power is 0.45W. Ice has a specific heat capacity of 2100 J/kgK. Let’s say that the danger zone occurs when the ice increases in temperature by 5°C (from a low starting point of about -30°C) as this will start to affect its mechanical properties negatively. That’s about 10,000J/kg. Each square meter of bottom surface has 500 cubic meters of ice above it, weighing 500,000 kg.

10,000J/kg * 500000 kg / 0.45W in seconds = 11,000,000,000 seconds

That 0.1W heat leak will take 11,000,000,000 seconds or 350 years to raise the temperature of the ice by 5°C

So, basically your iceberg will take multiple centuries to slightly warm up!

 

 

Insulating and Landscaping the Top and sides

For very large icebergs like A23a, the costs of the top and bottom will dominate on a per-unit-area basis because of scaling laws. The perimeter grows linearly whilst the area grows quadratically. The bottom can be quite cheap (air bubbles, plastic shade balls, etc).

The sides can be similar to the bottom, but made of some cheap neutrally buoyant material like expanded glass or expanded clay aggregate packed into a marinized concrete shell. It will be more expensive but the side surface is something like 100-1000 times smaller than the top and bottom surfaces so that’s OK.

But what about the top surface? The top surface of your engineered iceberg needs to be both structurally sound, stable and insulating. This is somewhat complicated by the fact that the top surface of an iceberg is made from compacted snow called firn which is less dense, more elastic and weaker than real freshwater ice. The Surface is also not flat - it has undulations and crevasses. A profile with a ~200 times exaggerated vertical axis is shown below.

For the top I think you can start with something like 50 meters of fresh ice which can be deposited incrementally as pure freshwater via a network of pipes and will freeze naturally. This layer will heal any crevasses and imperfections in the top surface and gravity will finish it to a very flat surface. Fresh, pure ice will also be somewhat stronger than the iceberg itself which is formed from a lot of compacted snow. Freshwater ice is stronger than seawater ice by about a factor of 2, and fresh water is very cheap to source either by melting other snow and ice or by desalinating truly massive amounts of seawater. 50 meters by 300 square kilometers is 15 cubic kilometers of fresh water, but each cubic meter of water only costs about $1 to desalinate, or $1bn per cubic kilometer. With access to cheap nuclear power I think this can be brought down by about a factor of 10, so you pay only a few million dollars per square kilometer of area, plus the one-off cost of a network of pipes and scaffold poles to deploy all that water evenly. Freshwater ice that naturally freezes in the antarctic is by far the cheapest building material in the world.

 

 

Reinforced Ice and Pykrete

A 50-meter thick layer of pure fresh water ice at about -35 degrees is a formidable structural element under compression, but it may be worth adding some Reinforced Ice on top to make the final several meters of the surface ice even stronger.

You can create a plastic-reinforced ice layer by adding a large amount of shredded or processed plastic waste to water. Ironically there may eventually be a shortage of plastic waste in the world because you’re going to want extremely large amounts. Plastic waste is cheap and fresh water is also free or very cheap. If you take the entire US annual production of Municipal plastic waste (about 40 megatons) and mix it 10% plastic to 90% water, that will give you a 1 meter thick layer of plastic-reinforced ice on a 300 km² iceberg.

You could probably also mix in plastic waste from the rest of the world along with basically anything non-toxic and solid you can get your hands on such as wood shavings, agricultural fiber waste like straw, etc. There’s about a gigaton of straw from rice, wheat and corn produced annually which is a waste product in agriculture, so you could probably grab that and perhaps compact it before adding it to your reinforced ice layer to add strength and reduce the thermal conductivity of the top layer. Ice reinforced with wood or other organic fibers is referred to as pykrete.

Sawdust/plastic pykrete is significantly stronger than regular ice under tension, and it can be further strengthened by adding reinforcing fibers akin to reinforced concrete. The beam below with just 1% glass fiber reinforced plastic (GFRP) is about 8 times stronger under tension than plain ice. If the ice was also mixed with 5% straw, sawdust or shredded plastic it would probably be stronger by a further factor of 2 or 3.

Since GFRP-reinforced or basalt-fiber-reinforced pykrete is basically as strong as concrete and about 50-100 times cheaper, it might be worth using it to create hollow, lightweight artificial hills and valleys on top of the pure ice topping layer, or other more exotic artificial terrain. Even in the most conservative case, some small elevations are necessary for passive water drainage

Below is a picture of Los Angeles from the air - a flat, uniform grid of roads and houses. Sprawl like this is not an efficient use of land and will not maximize the value of your land. Even so, vacant lots in this part of LA sell for $1bn per square kilometer.

Ideally you want lakes, rivers, gentle hills and tall buildings to maximize land value, as shown in this image of New York:

But this kind of hyper-valuable ($30bn per km²) land needs a very strong surface and it needs some minimal amount of elevation changes to properly drain the land and accommodate small lakes and so on.

Exotic topography also becomes possible with reinforced pykrete - you may be able to construct huge stacked layers about 50-100 meters tall made of reinforced pykrete with a whole city or park per layer and very convenient vertical transport between them. These layers will need a very slight amount of active cooling and a sensor network to monitor temperature, but I believe that it will be well worth it as you can make your land area much larger and massively improve transport efficiency due to verticality. Modern LEDs can make excellent and convincing artificial skies and arrays of fans and large air ducts can keep the layers pleasant and fresh.

The bottom layers could be for transportation and utilities. Most modern great cities have an extensive (and very poorly planned) underground layer, so I think even in the most conservative case there will likely be one dedicated pykrete sublayer in city areas with active cooling of the pykrete down to -30°C. There will be columns of reinforced pykrete in a regular grid with space in between them for whatever infrastructure is needed, and a layer of foam and very thin concrete insulation around those pillars. Pillar diameter might be 40 meters with 60 meters between them in each direction, and a 20-meter-thick reinforced pykrete upper deck. The layer might be 50 meters tall. This gives a fill fraction of about 30%, though you might also want arches and buttresses so it might be a bit more. Your nice engineered sublayer(s) will hopefully add a lot of value to cities by moving most transport underground and simplifying construction and repair of utilities like water and electricity pipes.

 

 

Look, Ma, No Ice!

Finally you want to finish your top surface(s) with something that doesn’t melt but that is also a good thermal insulator.

You don’t want to have to build a civilization on top of actual ice!

Lightweight aggregates like expanded/foamed glass will form that layer, though likely with a honeycomb of basalt fiber-reinforced concrete and a final reinforced concrete topping layer. That concrete will be expensive - $75 per ton -so 20 centimeters average thickness of concrete over 1km² costs $36M, and basalt reinforcement or UHPC may add to that. But $36M for a square kilometer isn’t that bad - an average house in the UK has a footprint of 77m² so you are paying about $3000 for that concrete layer on a house. The greatest challenge here will be making it very durable and ideally self-healing as well as strong.

The foamed glass aggregate under the concrete is mechanically strong but it is also a good thermal insulator, so the first concrete layer will not be cold.

All-in-all you can mostly make each square kilometer of insulated iceberg out of a combination of tiny amounts of plastic, recycled waste streams, expanded glass and a final layer of relatively expensive concrete. Oh, and lots of water! When these icebergs are under 100km² there’s plenty of cheap materials from humanity’s waste streams, but over 1000km² you really do need to make your own materials out of rock or perhaps some absurdly efficient fast-growing plant because the sheer amount of material required is huge. I think the materials cost for 1km² is around $100M and about double or triple that in city areas or significantly elevated terrain. As the operation gets large I think you end up manufacturing lots of things yourself to lower prices; perhaps at huge scale the cost of this land can get as low as $20M/km²

 

 

The finishing touches

Once you have made your land, you can start putting buildings on it, as well as dedicated parks, lakes, rivers, hills. You will almost certainly not be using this land for normal agriculture as it cost you about $20M-$200M per square kilometer to make, whereas arable land typically sells for a low price of $1.3M per square kilometer. This land is for people to live and work and enjoy themselves, or for high value industry like car factories or chip fabs that laugh in the face of $20M-$200M per square kilometer.

You could do modern vertical farming in a sublayer to make vegetables and cereal crops, and perhaps even lab-grown meat. But there is a global market for food and it is easier to simply buy it and store it than waste your relatively expensive land making food. This ability to cheaply import food as well as essentially any other product from existing terrestrial trade routes is a huge benefit over a space colony.

$200M per square kilometer works out at $66,700 for a 11 × 30 plot of land for a house. That may seem steep, but houses on your artificial island may be much cheaper than in legacy nations as you can reduce taxes and red tape that add a lot to costs, you can build higher, etc. You can also entice people with lower taxes and better demographics.

The high cost of ice-land is somewhat offset by the ability to make stacked layers of it. $200M for 1km² of land isn’t great, but if it is 10 layers deep then it’s actually 10km² of useable area with excellent transportation links.

Fictional islands like Ulthuan, Atlantis and Númenor could be recreated in real life, perhaps multiple times over.

 

 

Pure Industry on Ice

Although in the above analysis I have assumed the need for trees, lakes, nice houses etc it is certainly possible in theory to have a floating insulated iceberg that is dedicated to pure industry such as a massive floating chip fab or data center. The ice and pykrete is merely a physical scaffold that puts you out on the high seas away from legacy governments, and so may be used by a purely industrial or even AI-run network state, like the fictional 01 from The Animatrix. As long as you don’t have fully godlike tech to take over the world or colonize space, industrial ice-continents may be the best self-sovereign option for any kind of startup country.

 

 

Is it safe and stable? How quickly will the ice melt?

The iceberg itself will essentially never melt once it is properly insulated, due to the square-cube law. Real icebergs melt because the bottom sets up a nasty convection cell - cold water falls and warm water rises, but a layer of air/plastic-based insulation on the bottom will almost completely remove that convection cell. The warm water from the sea will never touch the ice. Some active cooling can be used over the longer term (thousands of years) though most likely by then we will have far superior tech anyway.

Without the melting effects of warm water, the iceberg will maintain structural strength and the layer of fresh ice on top will help. I believe that the final structure will be basically immune to any kind of weather or storm due to its gargantuan mass (multiple teraton range) and size. The edges will be vulnerable to wave erosion, but special precautions can be taken to harden the structure around the perimeter.

 

 

Mobility

OK, so you have a complete and insulated ice-continent or ice-island. But it is sitting off the coast of Antarctica in the freezing cold. You want to move it to somewhere with a warmer climate. How do you do that? Surprisingly I think the only viable answer is sails. A large number of sails will accelerate an ice-continent to a speed of a few knots in a few days, and I think that that will be enough to to crawl to the desired location over the course of a few years. Fleets of huge (and I mean HUGE) nuclear-powered pusher tugs are another option but they will only work if there’s no wind or current to fight against. So your island will have to use techniques from the age of sail most of the time.

Once in place it can probably be anchored to the ocean floor via lots of quite beastly cables. Whilst expensive in an absolute sense, I don’t think these will be that expensive per km² of land, as long as it is not anchored in a place with particularly deep water and strong currents.

 

 

Economics

Ice-islands are probably highly profitable in the right places but that will require cooperation from governments. Larger ice-islands can become de-facto sovereign nations out in the high seas. Agglomerative effects and (dis)economies of scale mean that small islands tend to be extremely poor places, but I think that over a size of a few thousand square kilometers an ice-island can be economically self-sustaining, especially if human capital is carefully chosen. Therefore they could fund their own creation by issuing bonds - so the cost of this scheme may well be negative in the sense that the market will pay you to do it.

 

 

Legal and military considerations

Any reasonably sized ice-island - even one thousands of miles from the nearest land - will likely need some political clout via political and ideological allies, propaganda, industry and lethal force in the form of a military.

If you need a small military anyway, why bother building the land - why not conquer it? Well, wars of conquest generally do not work out well in the modern world though there are some exceptions. Many great powers have waged wars and ended up with less territory than when they started, and less money despite winning the war (Britain in 1939 being perhaps the most notorious example). Russia’s invasion of Ukraine in 2022 gained it about 100,000 km² of land but it is unclear whether they will be able to keep any of it in the long-term, and they are losing lots of their trade and industry as a result. Israel has mostly conquered Palestine but they have suffered large reputational damage as well as constant low-intensity attacks.

The advantage of building (as opposed to conquering) land is that you don’t end up pissing off a specific adversary or isolating yourself from global trade networks.

Russia’s conquest of parts of Eastern Ukraine has cost them something like $1.5tr-$2tr for about 100,000 km² , which is about $15M-20M / km², around the more ambitious low end of what I think it costs to make a large ice-island. This is quite surprising - war has become so expensive that it’s starting to get close to the point where you can build new land cheaper than you can conquer it!

 

 

Is This a Distraction?

Does this Actually Matter in the AI Age? Shouldn’t we Reclaim Existing Land from The Baddies?

There is a reasonable concern that even thinking about this at all is a distraction from AI risk. But People do in fact spend time thinking about things like space exploration and network states. From a political point of view, having even a small sovereign country is a massive boon as has been demonstrated by the power of small countries like Israel and Singapore. Even Scientology at one point found it worthwhile to have a naval arm called “Sea Org” so that their leadership could meet outside of any political jurisdiction.

 

 

Conclusion

For something like a few tens to a few hundred million dollars per square kilometer, or a few tens of billions of dollars for a medium-sized city you can probably make a floating island with all of the benefits of a space colony and none of the drawbacks. The same amount of industrial effort spent on an actual space colony on The Moon gets you something the size of an apartment and at great risks in life and treasure, and you can quadruple the cost and risk for Mars, as well as adding a debilitating 20 minut communication delay and low bandwidth to Earth. Philanthropists like Elon Musk and Jeff Bezos should seriously consider throwing 10% of what they spend on space exploration on ice colonization instead. Similarly, people who are into seasteading and Network States might want to consider funding ice-colonization technology.

Update: here’s an executive summary of this idea:

https://transhumanaxiology.substack.com/p/ice-colonization-executive-summary

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