How would human civilisation develop with little iron?

Question

Imagine a planet that's identical in pretty much every aspect (including Homo Sapiens) to our own current Earth, with only a single exception - the continental crust has, for whatever reason, much less iron in it. What's in the core/mantle is not all that important, as long as it provides the conditions above.

I read that life could develop similarly with very little mineable iron (Can an earth-like world lack mineable iron?) so I'm happy with identical life forms. What I wonder about, is how would human civilisations develop if there were 10 times less iron accessible (with ancient and industrial revolution era technology) than there was in the Earth's actual history.

What would be the major differences? Would iron age happen at all? Would industrial revolution (leaving socio-economic readiness aside) happen at all, or how much later? How would it all change if there was 100 or 1000 times less iron available?

Answer 1

You'd barely notice a difference

... mainly because iron is so incomprehensively common.

Iron is about 1000 times as common as copper and 20,000 times as common as tin in the Earth's crust.

SEE: https://periodictable.com/Properties/A/CrustAbundance.v.html

So, even with 10-1000 times less of it, iron/steal would still be easy to make in significant amounts. At 10-100 times less common, you would probably not notice much of a difference in our world's history. Steel would be a bit more expensive, but still a pretty universally accessible metal. 1000 times less common, and it would probably extend the period of time where Iron and Bronze were used interchangeably much longer, but not really prevent the use of steel since it is still the better option a lot of the time. Instead of iron replacing broze, you'd just see each used based on when one is better than the other, or when one is more available in your region.

At 10-100 times less common, no industry would be significantly impacted from developing, but some places in the world might be iron scarce. This could affect the balance of power between economies throughout history such that some empires may rise instead of others and from this you could speculate all sorts of butterfly effects, but by in large, there would be enough places to acquire iron in that world that no country would be fully cut off from having it as a readily available resource.

At 1000 times though, you may also start to see the industrial revolution impacted, but not really prevented. There would still be plenty enough steel for mechanized production machines to remain economically viable. So early industrialization like grain mills, textile factories, etc. would still happen. But... things like trains, automobiles, and highrises use a LOT of steel, and this is where you would see the scarcity bottle neck maybe start to affect you. Just like copper started becoming scarce when we decided to wire and pipe up our entire world with the stuff, iron might become scarce if we tried laying down too many railroad tracks, making too many car engines, or making a bunch of steel framed highrises. There would still be enough viable ore to go around to get you started, but you'd often have to go farther to find it which would make it more expensive.

The transportation revolution would seem to be in jeopardy because of this except for a very important discovery that happened in 1888 called the Bayer Process which is where we learned to mass produce aluminium. Aluminium is even more common in the crust than iron; so, the Bayer Process opened up a virtually limitless supply of metal even without abundant steel. By replacing most of our bulk steel with aluminium, the industrial revolution could stay more or less on track. Aluminum, like copper, needs to be alloyed to become comparable to steel in strength, but instead of needing something rare like tin, it normally alloys with trace amounts of magnesium, silicon, and/or zinc which were all easily isolated elements by 1888; so, by the time the automotive and high-rise structure industries really starts to take off enough for steel supplies to be a problem, we'd already have enough enough access to aluminium alloys to pretty much replace steel even at very large scales.

The bottle neck would be cost, new aluminum costs about 3x as much as steel per pound to refine but is twice as strong for its weight. This would make things like sky scrapers much more expensive at first because you would need a similar weight of aluminum as steel to hold up the weight of all that concrete, but things like automobiles would be less affected because you are only engineering to the weight of chase. Either way, the cost of aluminum would cause an initial adoption issue for a few years, but would not stay a lot more expensive for long.

Aluminum is much cheaper to recycle, form, and transport than it is to refine. So, recycled aluminum products are only about 1/2 the cost of steel; so, as your civilization starts to have enough old stock to blend with the new stock, the cost of aluminum will drop to prices that could be comparable to steel today.

All this would really mean for anyone today is that cars would be a bit more expensive maybe making public transportation a bit more common and high rises would also not be as high. But on the surface, society and our history would still be pretty recognizable.

Answer 2

Ten times less iron would make iron more valuable but overall many things would look similar. Iron is very common. But if we assume iron is made scarce by these changes, then the world does begin to look different.

Brass, Bronze, and various formulations would largely replace iron

While Iron is more generally useful than bronze and copper and so on, there are still smithing and smelting techniques that can improve the qualities of other metals beyond the level it is generally assumed the bronze age sat at (especially considering many issues with various bronzes were caused by lack of tin or proper equipment).

However even so, the relative advantage of these metals is lower - they are rarer, and harder to produce - so wooden or even stone weapons would not be considered quite so primitive. Clubs and maces would potentially be more common, and more warriors might go armourless. Simple tools that rely on size or force might be still used alongside smaller metal tools that rely on hardness.

Skilled woodcrafting and wood treatment would be used in large-scale constructions and everyday goods for longer

While in many cases iron replaced wood for use in household items and such, the relative higher scarcity of copper would likely mean that things like lanterns or shutters, latches, locks etc would use treated hardwoods more often rather than metal. Likewise, lacquering would probably be more popular, as well as using high-labour cost expensive but tough fabrics.

Supply issues, technological issues, and social issues led some areas of Asia (notably japan but also many pacific islands, korea) to reserve iron for warlike uses and use more of other materials in construction and household goods - those are good references for the kind of workarounds in pottery, stone, cloth, and timber that humans will use when they don't have iron to spare.

Good steel would be more of a semi-mythical metal than an everyday item

How to make good steel was non-obvious. It took a very long time of constant and widespread use for people to figure out how to create stronger iron. If iron was rarer, there would be less opportunity for that kind of development - however, if it was rare, perhaps more effort would be spent on refining it (iron was largely improved when people figured out safe techniques to cheaply improve its quality - there were very labour intensive methods to improve the quality but those were typically only used to produce luxury items aimed at the upper class) resulting in a kind of 'damascus steel' where a labour-intensive (and secret) method is used to make good quality iron or steel. A well-made steel sword would give an immense advantage in a fight over a bronze sword or a club, as would steel armour over (heavier and usually not stronger) bronze, leather or wooden armour.

There would potentially be religious or social rules over the use of iron or steel, which did exist in some areas of the globe, but to a greater extent due to the rarity than existed in our world.

Industrialization would proceed significantly slower

Methods to produce strong materials that are not based on iron do exist but are often more difficult in terms of mass production. They rely on harder-to-produce raw materials and/or processing methods that take longer or require more complex factories and machinery that were produced later in the industrial revolution than industrial furnaces/smelteries and in many cases were powered by or relied upon iron equipment that would be more expensive to reproduce in bronze, wood, or stone.

The discovery and utilization of aluminium would be a far bigger deal

Although it is actually quite hard to get a usable metal aluminium out of naturally occurring minerals, in an iron-poor world having a sudden source of an abundant and useful metal would be absolutely game-changing and potentially kick off a harder and faster industrial age than had existed previously.

Answer 3

Although clearly less available than today, even at one thousandth the quantity we have there might still be substantial ore available because there is so much of it.

This might mean it was available to some nations and not others and it might run low before the iron age took off. But assuming a worse case situation where iron is not available in concentrated form any more It would change the course of history. The Bronze Age would last longer and instead of an iron age there would have been a nickel age or similar.

Answer 4

Many civilisations have developed with little to no iron. Maoris, for one. You would get a lot of fishing, wooden boats, sails etc but nothing very strong or long-lasting. Everything would need to be created multiple times and constantly repaired.