Water, water

This image has been going around the intertubes recently, I saw it first on Planet 3.0 and again on APOD. It is one of those interesting illustrations of large quantities that seems surprising or anti-intuitive either because you never thought about it carefully before or just because it is hard to get your head around sizes that are so far outside the realm of everyday experience.


Anyway, I am posting it because my wife insisted (a very unusual turn of events, considering the usual frown upon spending my non-work time on the computer!). When she saw it she became quite alarmed and thought people should see just how little water there is and how it is actually small enough that our polluting activities are a threat.

A new version popped up that puts the much smaller quantity of fresh water into perspective.

And don't forget that that ball of freshwater is mostly out of range of our drinking glasses and irrigation systems. A full 74.5% of that much smaller ball is locked away in ice caps and glaciers and 24.7% is groundwater (much of that out of reach). There is only .56% of the world's freshwater circulating in lakes, rivers, rainfall, soil and the biosphere.

We poison it at our peril, this goes without saying, yet I am sure another image of that much smaller ball of water set beside something on a more human scale, like a large city, would provoke an opposite "wow, there is so much!" reaction.

This seems to touch on a lot of interesting ethical communication issues, but I don't really know what to make of them. Is it wrong to pick the view that triggers the reaction you want ("Oh no! There is so little!" or "Bah! Look at all that, let's frac-away!"), even if it is what you believe to be the case?


More like this

That's actually way more water then I imagined.

By Jacob Schmidt (not verified) on 22 May 2012 #permalink

Completely and totally misleading. Every mention of this picture has been accompanied by warnings about the paucity of water on this planet and the need to be better stewards of our natural resources. I do not disagree with this general sentiment, but I would caution against the use of visual sophistries. Is that a small ball? Hardly. That ball contains approximately 380 Million Trillion gallons of water (about 7.6 Million Trillion of fresh water). For comparison, if an Olympic sized swimming pool holds about 100 billion rains of sand then to get to 7.6 million trillion grains of sand, you would need about 7.6 million swimming pools.

For this to be at all useful or relevant it needs a reference. If you want to show this as a historical point, it needs a comparison model. Big round globs of blue mean absolutely nothing in and of themselves without the available water change/lack of change.

By Jim Plassard (not verified) on 22 May 2012 #permalink

Why does it need a reference to be useful or relevant.

Look how big that ball of rock is.

We live there.

Look how small that ball of fresh water is.

We pollute that.

If you really don't give a fig, then there's nothing that could make it relevant for you.

So why pander to your whim?

I thought this comment from elsewhere was worthwhile:

If you want to make something sound big, you describe it in terms of area or length. If you want to make something sound small, you describe it in terms of volume. So, when someone tells you how many times all the X's would stretch from the earth to the moon and back, they're almost always trying to make X sound very abundant. In contrast, when someone tells you the dimensions of a swimming pool that would hold all the X's, they're usually trying to make X sound scarce.

This is the visual equivalent of that trick. We see the earth's crust stretched over a huge sphere of other stuff (as in reality), but we see the water forming a 100%-water sphere, with nothing else inside it (unlike reality). As a result, the water looks woefully inadequate to give the earth what it needs.

-- John Cohen, via Metafilter

There are some other good comments there, although much of it is off-topic.

that was sort of struck home to me on one of our trips up to Lake Superior.we were viewing the lake from a pier at the town of Two Harbors when i said something to my Wife about how vast Superior was.a fellow taking photos at the light house said something like " see that ore boat way out there,if you stood it on end more than half of it would be out of the water"that comment made Superior a lake and not the Sea,a lake just like some of the small ones we canoe around on that have 100 foot holes.

Does that include water deeper in the Earth's crust and mantle?

If the large ball included al the water within living things, would it be any larger? I know the answer is almost certainly no, but now I'm curious.

Anyway, it's true to an extent that all visual representations of data can be misleading. Hypothetically, one can imagine a biosphere which actually uses an unimaginably small fraction of that water to live, hence the blue ball being so small relative to the Earth would be irrelevant. But we're not that biomass.

We see the earth’s crust stretched over a huge sphere of other stuff (as in reality), but we see the water forming a 100%-water sphere, with nothing else inside it (unlike reality).

I somehow initially read this as referring to the usual depictions of the Earth, and agreed with what I had thought was John Cohen's point (the real point may actually have been somewhat opposite). When we see a normal image of the the Earth, we may know "intellectually" that the water merely covers a rocky sphere, but it sure looks like the planet is actually a big ball made of water, with some continents on top. Even while knowing the actual situation, the brain may still "trick" you, just like optical illusions can persist past knowledge of how they work. So, images like this one help balance out that natural subconscious impression.

This impression is probably the main reason the image feels so "surprising" (at least if you weren't asked to predict what it would look like beforehand). If you see a photograph of a naked person carrying their own clothes as tightly bunched as possible, you won't feel surprised at how small the total volume of the clothes is compared to the person, but with this naked-Earth image, there's a distinct sense of "huh, that can't be right…"

By the way, I recently had something of the opposite experience when I found myself surprised by how full my house's rain barrel became after a single half-hour storm. I had to think somewhat hard to intuit the way in which the house's gutter (which all goes into the barrel) has a large total area despite its narrowness, and this area multiplied by three inches of rain can result in over forty gallons.

That picture effectively compares the water to the volume of the earth, which is unfair.
Using their data I calculated that if that water was spread evenly all over the WHOLE earth, not just in the oceans, so it is equally deep everywhere, it would be 2.8 kilometers deep. As high as when I go skydiving, EVERYWHERE. That is a lot of water.

By David Gransden (not verified) on 24 May 2012 #permalink

Just a quick note on comments and moderation. This is all new, what with the Nat Geo merging and I am finding everything seems to go into moderation. I will do my best to clear things quickly and make it so this is not the new normal. When you post from NA time zones, remember I am in Australia so won't be able to do anything til late afternoon your time.

"That picture effectively compares the water to the volume of the earth, which is unfair."


Now calculate the size of a sphere representing the amount of CO2 in the atmosphere. I can tell you, it would be completely invisible.

The invisible sphere of CO2 is all we've got to keep us and every other living thing, alive.

Stop worrying about the amount of water available to us, and start worrying about the amount of CO2 that's available to us. Going on the track record of scientific prognostication over the last 1000 years, the prevailing consensus of 'experts' at the time, has always been wrong.....100% of the time. If you don't believe this, cite an example of when the scientific establishment, at any time during the last 1000 years, has been right, on any subject. It has always been the individual, the sceptic or 'denier' as they are referred to today, to get it right.

What is more remarkable though is that whenever the scientific or academic establishment delivers a prognoses, it not just wrong, it's often opposite to the truth.

Like in 1665 when the then Government advisers insisted that the outbreak of the Black Death was due to cats so, having given the order for all London Cats to be destroyed, The Black Death immediately turned into a disaster of epic proportions, the rats now being freed from its only natural predator.

The academic consensus today tells us that CO2 levels are rising. As always, they will be wrong. More importantly, they will be shown to have got the exact opposite of the truth, ie, CO2 levels are probably falling.

The 100% track-record of establishment advisers says that the truth lies with the individual who stands alone and contradicts the academic consensus.

By Justin Gudgeon (not verified) on 24 May 2012 #permalink

"Is it wrong?" you say.

To be honest, right or wrong it's probably unavoidable. Like any executive summary. Particularly if it's the image which formed one's own opinion on the subject, where the bias is presumably more unconscious than conscious. I first saw a picture like this on Prof Ian Stewart's geology series for the BBC where it was presented without any kind of reference to pollution etc. So it looks like the pollution association came later.

One can debate linear vs. area vs. volume graphs until the cows come home. However, in this narrow context it would see that the principal omission in this particular image is a ball showing the quantities of pollutants we're dissolving in that water.

As always, the Golden Rule is to ask "What's this guy trying to sell me?"

By Ian Kemmish (not verified) on 24 May 2012 #permalink

Justin Gudgeon:

If you don’t believe this, cite an example of when the scientific establishment, at any time during the last 1000 years, has been right, on any subject.

Ooh, I've got one! In 1843, the scientific establishment held that the Earth was round and orbited the Sun. I have a near-infinite supply of other available examples, of course…

It has always been the individual, the sceptic or ‘denier’ as they are referred to today, to get it right.

Of course, it's not too difficult to find instances of the "deniers"/skeptics of the consensus being wrong. The only trouble is that this makes them quickly forgotten. There isn't room in the history books for every nut with an idea, eg, Emoto's "water emotions" experiments and whatnot.

As a result, there isn't a plethora of historical stories along the lines of "lone maverick takes on the establishment and loses"; they're equivalent to "dog bites man" in their commonness.

In any case, if you truly feel that the establishment is always necessarily wrong, then there's no hope for any truth to become established, is there? As soon as the scientists agree with you that CO2 is falling (a claim which, by the way, I've never seen anyone make before,m skeptic or no), then whoops, reality will make sure to do the opposite, right? I can only hope that scientists convince themselves that I, Lenoxus, am destined to be sick and poor.

I am much concern with the usage of fresh water. As we can see very small amount of fresh water is available for the drinking purpose. But still we are not considering this issue to be resolved and save the earth. The beauty of the earth is with the availability of water but human are not in a mood to save this important blessing. “SAVE WATER SAVE LIFE”

By kousar khushwali (not verified) on 29 May 2012 #permalink

The approach to explain the volume of earth and water is very interesting but the figures seems a little bit higher. acording to Howard Perlman (2012) total fresh water in the form of Ice caps, Glaciers, & Permanent Snow is almost 68% while the ground freshwater is 30.2%. Still the situation of avalaibility of water given seems true as Howard Perlman (2012) also mentions that over 99 percent of all water (oceans, seas, ice, most saline water, and atmospheric water) is not available for our uses. And even of the remaining fraction of one percent (the small brown slice in the top pie chart), much of that is out of reach.
U.S. Department of the Interior | U.S. Geological Survey
URL: http://ga.water.usgs.gov/edu/earthwherewater.html
Page Contact Information: Howard Perlman

Hi Coby,

Thanks for using my graphic, illustrating Earth's fresh water.

Just to clarify, the fresh water sphere doesn't include glacier sources. See the notes at my article, and the link to the USGS source data.

Accessible fresh water is about .77% of all water (ground water, lakes, rivers, etc.) N.B.: An additional 1.74% of global water is stored as glaciers, ice caps and permanent snow, but is not accessible and usable.

Jay Kimball
8020 Vision

By jaykimball (not verified) on 29 May 2012 #permalink

"The invisible sphere of CO2 is all we’ve got to keep us and every other living thing, alive."

And doesn't that rather indicate that CO2's effect is rather important?

"and start worrying about the amount of CO2 that’s available to us"

We don't need any more CO2.

If more CO2 were needed, it wouldn't be growing so fast: the ones "needing" it would be eating it up quicker than we're producing it and the seas wouldn't be taking it up and becoming more acidic.

Changing the focus slightly, but still on the subject of water, here is an interesting new paper on ocean warming published yesterday:

This is the concluding statement from the Abstract:

".....we consistently obtain a positive identification (at the 1% significance level) of an anthropogenic fingerprint in observed upper-ocean temperature changes, thereby substantially strengthening existing detection and attribution evidence...."

And in an interview for the Australian ABC, one of the paper's authors had this to say:

"...This paper's important because, for the first time, we can actually say that we're virtually certain that the oceans have warmed, and that warming is caused not by natural processes, but by rising greenhouse gases primarily." And he described the evidence of global warming as unequivocal. "We did it. No matter how you look at it, we did it. That's it," he said...."

I wonder how the denialist machine will spin that one.

I wonder how the denialist machine will spin that one.

I actually went and checked. Hehe. No mention of it that I could see on everyone's favorite faux-skeptic website.

Speaking of Wattsup, while I was over there I noticed another unbelievable whopper by the esteemed Mr. Watts. This time he linked to the wrong journal regarding an article supposedly showing that random walk-generated trends were better predictors of climate than conventional models. Hard to explain all the details but I tried to sneak a post past the moderator/henchwoman that acts as the Thought Police on that site. We'll see if I succeed. This time I was careful to send it to myself first.