So in my home-brew world, the Gods basically put a giant, magical barrier around an entire continent. The gods do not interact with anything inside the dome, it operates in a way similar to an Earth-like planet.

Rules of the barrier:

  • The barrier is semi-spherical and completely encapsulates the continent.
  • Living things cannot pass through the barrier.
  • Sunlight can enter and leave the barrier.
  • Water cannot pass through the barrier, including water vapor.
  • The barrier is a complete sphere that extends beneath the earth.
  • The barrier is not perfectly spherical underground, being more shallow and extending 100 miles beneath the surface. The continent sits on one, unbroken tectonic plate, so the barrier does not move through fault lines. Bear in mind I am not too familiar with geography and the intricacies of plate tectonics, so if that it not possible, I would imagine that the barrier allows for the passage of earth/magma through it.

I have some experience with predicting climates and geography based on where a landmass is on a planet, assuming near-Earth characteristics, like east-west wind vortexes and mountains affecting desert formation. But seeing as this is a little more complicated (or maybe it isn't?) I wanted the opinion of the community.

How would the presence of this barrier affect the climate and geography of this continent differ from a similar landmass that lacks such a barrier?

Below is a picture that shows the continent in relation to its position on the planet, including scale in relation to a map the the United States.

World map and barrier's size

  • $\begingroup$ I believe you forgot to finish the last sentence before the image ("but because ...") :) $\endgroup$
    – Joachim
    May 21 at 15:21
  • $\begingroup$ Where in the world is the dome? Near the equator? Over a pole? $\endgroup$
    – sdfgeoff
    May 22 at 3:52
  • 1
    $\begingroup$ What do you mean by "dome"? Since you're asking about landmasses, is it a sphere, a demi-sphere? How deep and how high does it dig/peak in? Does it move with the crust or does it stop it straight? The more the details of the magic is known, the better! $\endgroup$
    – Tortliena
    May 22 at 9:41
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    $\begingroup$ This is not an answerable question as it stands. You're going to need to define your map with a lot more detail (latitude lines, for instance) for us to judge even normal climates, and then you're going to have to show where this dome actually is (right now, it looks like "the entire world", not "one continent") before we can take any guesses at its climate impacts. You're also going to need more details about the dome (does it go underwater, for instance). $\endgroup$
    – Palarran
    May 24 at 11:25
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    $\begingroup$ "Water cannot pass through the barrier" - what about water vapor? $\endgroup$ Jun 1 at 16:26

2 Answers 2


Bottled ecosystem

Have you ever seen a bottled ecosystem?

bottled ecosystem

They work thanks to their simplicity. Nothing can escape the system and all that is required to keep going is sunlight. Sunlight guves the plants energy to griw and do their processes. These processes allow for others to eat it alive or compost the dead parts. This in turn gives the plant sustenance again. Water evaporates and trickles back down the bottle. If the bottle would be big enough it could create it's own (rain) clouds.

What you have done is bottle a continent,minus one or two things. Because of the size, you can expect similar weather. Areas will still heat up or cool down, causing high or low pressure, which will result in wind. Water will evaporate, rain will fall, clouds will form. Sure we will miss the extra water some storms from further away would bring, but water also wouldn't leave.

The true result on the weather is difficult to know. Currently we have many big computers calculating the weather, but sometimes we still get surprised. In your dome I expect less extreme weather, as there's less chance for big build ups, but I might be wrong. You will probably have some more rain on the edges of the dome, but a storm would only bring wind, possibly weakened by the sudden dryness as it crosses the barrier.

Many other large things will stay more or less the same. Tides will continue. Waves will crash in the shores. Migration is severely reduced, reducing biodiversity, but things will evolve around it.

Wind will still blow in fertile sands or blow them out. So much will be unchanged that the effect won't be huge.

Thanks to the size I think it will hardly change. A few strange things will definitely happen and cause some interesting weather, but in the grand scheme of things it isn't a big deal.

  • $\begingroup$ This is super helpful, thank you! I was worried that their would be just too many issues/problems with the set up to predict the results, but this makes a lot of sense, thank you! $\endgroup$
    – Grail
    Jun 5 at 21:57

Ask gods, not humans

When gods are controlling everything and they change whatever, whenever, how can somebody predicts what gods will do next?


Let gods make certain rules or laws (of physics, chemistry, math. etc.) and run the world under these rules. Only then somebody can predict what happens when.


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