[mesot420]

I was having an argument the other night with my husband and he said that we've had the same amount of water (volume) since the beginning of time. I said that slowly humans have been comsuming it and that we may still be close to the same amount but it has decrease because water may be the miricle of life but it's not created miraculously. Am I right or is he.

[ashley0716]

Well I'm not a scientist, but our bodies are made of mostly water and there are BILLIONS of people on earth NOW versus the beginning of time, so my educated guess is there is less water. Hence the reason lots of areas in the world are suffering a drought and have water usage restrictions. I live in Savannah GA and I'm not allowed to wash my car or water my lawn. And your husband needs to understand, that women are ALWAYS right!

[ebaines]

I'm afraid you're both wrong. First, you husband is wrong because there are plenty of chemical reactions that occur all the time that change water into something else (hence depleting it), but there are others that create water. Some examples:

1. Plants combine water with nutrients from the soil and energy from the sun for photosynthesis. The result is that water gets locked up into the tissues of plants as something other than water (such as sugar), thus depleting the amount of free water molecules in the atmosphere and in the ground.

2. When you burn any fossil fuel the main ingredients of the fuel are hydrogen and carbon. For example the principle ingredient in gasoline is octane, consisting of 8 carbon atoms and 18 hydrogen atoms. When octane burns the carbon combines with oxygen to create carbon dioxide, and the hydrogen combines with oxygen to form water vapor. That's why you sometimes see water dripping out the tailpipes of cars on cold days before the car is fully warmed up - that's the water vapor condensing out of the exhaust. Hence as humans use fossil fuels we are adding to both the carbon dioxide and water vapor content of the atmosphere. Carbon dioxide is of course a green house gas; water vapor can be too, but in general it precipitates out as rain.

3. Also, scientists believe that over the millennia comets that have hit the earth from space have contributed to the overall quantity of water.

So the total amount of water on the earth has certainly changed over the years. But whether it's more or less is hard to say.

Not sure what you mean by humans "consuming" water, unless you mean the water locked up in our bodies as Ashley suggests? Of course, that water gets released after you die and your body decomposes.

[firmbeliever]

Where is Earth's water located?
Huge 'Ocean' Discovered Inside Earth | LiveScience
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