On Earth, we have problems with rain and other forms of precipitation: either it's absent for too long and it causes droughts and ecological disasters, or it's way too plentiful and it causes massive floods and human misery. it's also hard to predict when the rain would fall and rain, snow, hail and so on that falls at the wrong time has been known to cause significant safety problems and ruined moments.

So I was considering to have the society in my fictional Earth world to have geo-engineered the global weather system such that there is a predictable amount of rain, snow, hail, or other forms of precipitation every day of the year, but at the same local time of day. In effect, it's a perpetual precipitation system that is perpetually maintained at a certain position relative to the position of the sun, but as Earth rotates, the system would not move along with it, instead staying in that position above the planet. This system would have been activated roughly within the next century and already been running for a couple centuries by the time the story happens.

This example is purely hypothetical: if the system was designed to always rain at 3 AM, it would stay in a location such that the time zone where it is currently 3 AM (in this world time zones are not the mess they are on our planet Earth) would always be directly underneath it. It would always rain at 3 AM in this example no matter what part of the planet you look at, and while the rest of the day would have a variety of sun, overcast weather, wind and temperature change like a day on our Earth has, rain would only fall at 3 AM.

One consideration I have already made is that not every region would want rain at the same time of day, and some areas might want rain more than once per day or not every day. So I would also accept solutions where the rain is more or less frequent than once per day, as long as the rain cycle itself would actually be predictable in when it happens and how much falls out of the sky.

The problem I have is that I do not know nearly enough about global ecology and the rain cycle to gauge whether this idea would actually be an improvement over our current situation from that perspective. There are probably considerations that I haven't made, like the effects on animals, and whether wild plants and animal may suffer adverse effects from this. I know there currently are already areas with wet and dry seasons which may not react to this change well. Or I might be underestimating the resilience of these systems and how it might even improve them...

Would a weather system like this be problematic for Earth's ecology as a whole? Or would it actually be an improvement long-term over the current "it happens whenever it happens" weather system?

  • $\begingroup$ The description looks quite similar to Master of Orion 2's Weather Controller tech/system, and frankly I think that this system will overall improve global weather, or at least be tunable enough to improve weather over cultivated areas, allowing better crops and less worry about draughts or fires. Also you can allow this system to not control weather over faraway ocean, in case there would be imbalanced rain vs evaporation, to allow normal weather to compensate. So the answer is IMHO "improvement over existing", but can't exactly predict what will happen. $\endgroup$
    – Vesper
    Commented Aug 4, 2022 at 14:19
  • $\begingroup$ @Vesper "improve weather over cultivated areas" so what's wrong with irrigation then? we already have it, it's well understood much lower tech (🤔 it barely even qualifies as 'tech' really 🤗) is easier and likely far cheaper. $\endgroup$
    – Pelinore
    Commented Aug 4, 2022 at 16:23

2 Answers 2


Rain (like Luck) Favors the Bold:

Your system would be wonderful for agriculture (at least in the short term), since the water supply would be utterly predictable. Crops are designed or selected to produce abundantly if at all possible. They fail horribly without the care of humans who assure these plants are cared for. They are bold plants.

Some plants are adapted to grow and spread aggressively. These plants do well in environments where they can find the resources to do so. They choke out the competition by expanding rapidly and constantly. But when things get bad, they collapse, relying on sheer numbers and volume to guarantee survivors. They are bold as well.

Diseases and insects require specific conditions to grow and spread. Often, they need plants to be at a high density and growing well to spread effectively. Seasonal cold and drought kills insects and chokes out molds that can otherwise rot crops. They are bold.

But most plants (and animals) are more conservative in their evolution. They depend on seasonal variations for having the right amount of water at critical times, and have evolved mechanisms to deal with drought conditions. Other plants depend on dryness to prevent molds and diseases from spreading out of control.

A lot of plants also need different amounts of water to thrive - compare rice and cranberries (which need water-filled paddies and bogs) to agave (which requires quite arid conditions).

So a constant water supply will be great - for plants that want to choke out the competition. In the short term, it will be great for agriculture. Those plants will have ideal growth conditions to make food. You would need regional differences in total rainfall to allow for different crops, however.

But the plants that need cycles to reproduce and thrive, and those who depend on competitive plants dying off periodically, will be brutally out-competed. There will be a mass extinction event as biological systems simplify under a single pressure to grow. And those same rapidly growing plants will start to compete with your crops as they try to invade your agricultural land.

Yes, your society can use technology to protect their crops. But they can use the same tech to irrigate fields in a controlled fashion that won't disrupt the environment.

So use your tech elsewhere, or introduce a locally significant variation in seasonal, regional and daily rainfall. Oh, wait, that's what we already have...


One potential problem

Your storm(s), which remain(s) effectively stationary with respect to your planet, is moving at close to 1,000 mph relative to the planet's surface. So, unless your rain has a good method of slowing down, it would have so much energy that it would evaporate due to atmospheric drag, or if it didn't, the high speed rain would tear through crops and damage everything else.


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