It is common to hear things like it takes one gallon of water to create a single almond, or watering a lawn can take X gallons per month/year, or it takes X gallons to make one pound of beef or yield X pounds of alfalfa.
My question is, is that water “gone forever”? Or does the water thats used return to the water table/cycle in some other form. When you water the lawn does a large amount of that seep into the ground, evaporate, and return to the atmosphere?
Or is the water used in these ways truly gone forever (in terms of humans being able to use it again)?
The question is a bit like “If I spend all my money, is it truely gone forever or did it just return to the global financial streams?”
Like with the money, water exists in very different states of usefulness. Sea water, for example, is incredibly abundant, but using it requires desalination, which requires enormous amounts of energy.
Ground water is really useful, because it’s where you need it and it’s usually pretty clean.
Rain clouds mostly pull their water from the sea. Hence using water e.g. in agriculture will not increase the amount of rain by any significant amount.
Ground water replenishment thus doesn’t depend on the amount of ground water spent for e.g. lawns. Similar as your wages usually don’t depend on how much money you spend on a holliday.
So if you waste ground water, it’s mostly just gone, while you wait for rain to refill it. Sadly, in most regions that happens far slower than people are spending their precious water resources on useless nonsense like a green lawn.
You can’t destroy it and it doesn’t go anywhere. It just gets moved around and used for different things at different times.
Water lawn > Grass uses water to grow more grass > humans mow lawn > grass clippings dry out > water returns to atmosphere
If everyone on earth died at once and decomposed, how much water would be returned to the environment?
Very little, tiny fractions of a tiny fraction of a percent of the water on the planet.
Maybe a few years, once the ISS crashes down to earth as that is one of our greatest of planet reserves
What about something like electrolysis where it’s separated?
If you keep them separate sure, but the moment you burn hydrogen it just turns back into water.
So then the truth of the matter is that we can create water from hydrogen and oxygen and we can also destroy water by reducing it to its elemental compounds. As such, water can be created and can be destroyed, meaning that the overall level of water available on earth can change over time, however our commonest uses for water have it not be destroyed and eventually return to the water cycle.
Technically, yes.
Realistically, any amount we split/convert is so small as to not matter to anything. The amount of water on the planet is absolutely ridiculous. 1233.91 quintillion liters to be more specific.
Depends. Sometimes the water gets dirty and needs to be treated, sometimes it evaporates and needs to rain, sometimes it could be reused as is
In very rare cases (nuclear fusion) the water is destroyed into its primitive elements
While the water most likely returns to the cycle, in many places replenishing the aquifer can actually take years, even decades. In those places using too much water means the aquifer keeps depleting and causes a bunch of other problems such as salt water intrusion.
Another factor to add to these answers: if the water has been treated (if it’s mains water), then a not inconsiderable amount of electricity (and so carbon emissions) will have been used to treat it, and probably quite a lot more electricity will have been used to pump it around the country. So using water is also burning energy
It’s a cycle, but it’s not in balance.
There is a lot of water on earth. Most of it is salt water which is not usable for crops or consumption etc.
The graphics on this Wikipedia will give you an idea of the distribution: https://en.m.wikipedia.org/wiki/Water_distribution_on_Earth
The water we use for food production, watering lawns, bathing and toilet flushes is pumped from the fresh ground water, which is only about 0.76% of all water on earth.
When we use water, it will eventually, one way or the other, flow into the sea, where it turns into salt water. The evaporation from the sea will create clouds that will rain and seep down to become fresh ground water again.
The problem is that we are basically taking the tiniest bit and turning it into the largest faster than it can be replenished.
