Eli5 how could we ever out of water if it never leaves the Earth's atmosphere.
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Posted Mar 26, 2022, 11:24 AM UTC
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Well, it does leave our atmosphere but not at any rate we have to worry about.
Almost all the water on Earth is not drinkable. It's seawater. It's locked up in glaciers. Etc, etc, etc. It's just a tiny bit that's drinkable.
And Sci Fi is "so obsessed" with showing a dry, barren Earth because that's probably what you're interested in and so it's what you consume. There's plenty of Sci Fi where the Earth is perfectly fine. Utopias even.
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Thank you. Yes I seem to gravitate towards post apocalyptic scifi or space scifi..
It typically shows the earth (as is now) but brown and no ice caps. Therefore stemming great googling and reading. And to me it doesn't make sense. We have the ability for light travel but now desalination?
For me the expanse hit it well. High salt water ruining everything.
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If things get too warm like in deserts the water goes into the air and makes more clouds and those are not easy to drink like water from the ground. Also if it gets stuff in it like trash or tiny bits of rubbers and plastics or chemicals from farms or factories or cars and stuff it gets harder to clean into drinking water. So if we keep the water filters we have and the water gets dirtier, we get less pure water out of the filters and that is what we may run out of more easily, the pure drinking water.
On the big scale, if the magnetic field of the planet goes away we will lose a lot more air and water into space. When the sun gets bigger it will be closer to the planet and that will heat the planet more and also blow the upper clouds and air into space more.
If the sun was smaller before, it's possible that mercury and venus were once like earth - so we can guess what might happen to earth orbiting a bigger older sun, it might end up looking like those planets with almost no water at all. And if it continues like this with the sun getting bigger and stronger with winds, mars may one day be like earth and even the gas giants like jupiter and saturn might one day shed their excess gasses and turn into smaller rocky planets like earth
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Wow. I greatly appreciate your response. Time for me to read more.
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A good chunk of Sci-Fi and speculation involves Mars, a planet that is dry and barren. There are theories that a long time ago it did have life, and we are seeing its post-apocalypse state. The Martian Chronicles, as well as the Martian Manhunter/J'onn Jones are examples.
A dry and barren earth makes clear that life, at least life anything like we know it, is gone. Space exploration has found very little water in our solar system.
It is similar to various monuments/landmarks. Seeing the Statue of Liberty buried shows just how bad things got in Planet of the Apes.
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To be technical, it's very hard for us to run out of actual water to drink. If push comes to shove we can purify salt water like some countries do right now, it's just not worth it right now for most part. And that water is mostly again used for purposes other than drinking, we require very very little of the water we use today if we just wanted to drink it.
Most water is used for agricultural purposes, some say around 70%. So we need it to produce food, and most of the other water is used for industrial purposes, domestic usage accounting for the water usage after that.
Again though, unless something very catastrophic happens that we run out of water to use, it's unlikely that we run out of water on earth. Water is one of the most abundant things on earth, even just accounting fresh water. If push comes to shove, there is always sea water to use. So the catastrophic desert planet and people fighting for water to drink is something quite unlikely to happen.
That being said, specific areas (mainly areas that already have less water to begin with) due to bad water policy can become deserts or run out of water (directing it to some other area in effect), so earth doesn't run out of water, but that place can have water shortages and the population would be forced to migrate to another area (making the country in effect collapse and cause all kinds of problems), and we can pollute water making it harder to use.
TL;DR Earth on a whole is unlikely to run out of water, bad policy can make specific susceptible areas run out (directing said water to some other area on earth) forcing the population to migrate to another area (collapsing the country/city/area).
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Thanks!
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All the land could have become deserts, but we could still have water in the oceans. Desertification exists, even long before climate change and Greta. If something happened for ALL the water to leave the planet, we probably wouldn't be here anymore.
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I also appreciate your response and agree.
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Because it is not water that is rare (about 2 thirds of our planets surface is covered in it) it is Drinkable water. Which is what we use to grow crops & drink.
If temperatures rise too much, evaporation will increase, causing there to be more clouds & less surface water.
If we pollute the land, then the rain is spoilt as it collects upon ruined ground, or when it falls in the oceans, as it does today, becoming unusable.
Thank you for your response. I appreciate it.
Fun tidbit, while the commonly accepted scientific theory of where Earth got it's water is that it is extraterrestrial in origin, coming from comets etc, some say that it came from the rocks that were originally smoothed together to form Earth to start with.
Link: https://www.google.com/amp/s/amp.abc.net.au/article/12598198
On top of that, just because the quantity of water on Earth doesn't change radically, doesn't mean it's where you want it to be.
Both the Sahara and the polar regions used to be lush forests for example. Now they're both arid because there either isn't any water or it's frozen.
The ongoing climate catastrophe is already creating incredible droughts in growing parts of the world while causing excessive rainfall in others. That's why you're seeing things like excessive wildfires in the US and Australia beyond what is normal for example.
My own country is famously wet and rainy for most of the year. But for years after years now we've had springs and summers that are far too dry for us and autumns that are disastrously wet because all the water falls in an increasing number of massive storms instead of drizzling throughout the year.