Though I’ll admit Tolkien could be an outlier here. He seems to have been quite thorough on a bunch of things.
To quote a military historian‘s analysis: „ Tolkien’s first-person experience of war and his deep grounding in medieval and Anglo-Saxon literature means that – while Tolkien does not stop to discuss Aragorn’s tax policy – Middle Earth tends to fit within the ‘zone of the possible’ much more neatly than Westeros. Armies in Middle Earth move at normal speeds, the economic and population systems (and the human terrain with them) make sense, characters behave within the confines of religious belief and social custom, and so on.“ (https://acoup.blog/2019/10/06/new-acquisitions-how-fast-do-a...)
I just read it because I’m thinking about writing a crossover fanfic between Tolkien and Sailor Moon set at the end of the Fourth Age/Silver Millennium, and I need to figure out the geography. I’ve mainly settled on throwing out Tolkien’s map, drinking a long draught of Graham Hancock kool-aid, and setting the thing in the Younger Dryas. (The core conceit: Eärendil’s silmaril === Usagi’s silver crystal.)
http://www.accessdenied-rms.net/forums/showthread.php?tid=13...
It's a bit similar to the world in "Game of Thrones": that one too is a fantasy world that doesn't follow the regular laws of astrophysics, and doesn't even appear to be a planet at all.
The final war with Morgoth also destroyed a good chunk of western middle earth
With such common and devastating divine interventions it is not surprising that plate tectonic is not a good predictor of geography :D.
Note that Arda is supposed to be planet Earth , circa ~10000 years ago, but of course the geography only vaguely matches.
Many subsequent authors will have only seen modern or American or no countryside at all and get their impressions of "the middle ages" from a mostly-fictional cultural pastiche of Tolkien (who was really writing a Late Antique world), Dungeons and Dragons, Monty Python, etc. so it's no surprise their worlds are rather implausible.
I agree with all the rest of your comment, but I think this point is only partly correct. Gondor can be interpreted as Byzantinian (late Antiquity), but Rohan is rather Anglo-Saxon (early Middle Ages), and the Shire actually quite modern (18th-19th century England). Numenor of course is Atlantean (romanticised classical Antiquity), the Druadain are Stone/Bronze Age, and the Elves - are the Elves.
European populations were not at all static. There were many massive population declines more or less going back to the beginning of agriculture as far as we can tell https://en.m.wikipedia.org/wiki/Neolithic_decline
Climate change, the plague (usually one accompanied the other) and to a much lesser extent warfare occasionally reduced populations on a regional scale by more than 70%. Often leaving large areas very sparsely inhabited or even abandoned.
As dar as we know the last major plague in Middle Earth occurred almost 1400 years before the events described in the LOTR yet the populations never seemingly recovered in much of it.
In contrast in Europe recovery took about 300-400 years. However we must take into account that the plague remained endemic and kept reoccurring regularly during those periods, which put a massive downwards pressure on population growth.
From what we can tell human populations can grow at an extremely fast pace by premodern standards if resources are ample and climatic conditions are good.
For instance according to some estimates the populations of medieval England and some other countries in Northern Europe might have almost tripled between the 1100s and the 1300s.
In a completely empty place like Eriador that must have happened at an even faster rate (e.g. the British colonies in New England).
After the collapse of the Northern kingdoms Bree supposedly thrived for centuries without any major calamities. That doesn’t make any sense though, assuming a couple of thousand people lived there initially with all the ample land a population of ~2000 would have increased to over 100k at a somewhat conservative growth rate of ~2% (and it’s unlikely that its initial population could’ve ever been that low considering all the refugees etc.). Something similar applies to the Shire as well.
So overall I don’t think we can really apply real world demographics to middle earth. There certainly must have been some force/factor not directly described by Tolkien that kept growth rates very low.
>So overall I don’t think we can really apply real world demographics to middle earth. There certainly must have been some force/factor not directly described by Tolkien that kept growth rates very low.
Perhaps women in Tolkein's world are far less fertile than in our world (except for Samwise's wife). Or maybe they developed some effective contraception.