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Human Water Use Accounts For 42% of Recent Sea Level Rise

Unknown Lamer posted more than 2 years ago | from the global-plot-to-drown-new-yorkers dept.

Earth 324

scibri writes "During the latter half of the twentieth century, global sea level rose by about 1.8 millimeters per year. The combined contribution from heating of the oceans, which makes the water expand, along with melting of ice caps and glaciers, is estimated to be 1.1 millimeters per year, which left some 0.7 millimeters per year unaccounted for. It seems that the effects of human water use on land could fill that gap. Researchers report in Nature Geoscience that land-based water storage could account for 0.77 millimeters per year, or 42%, of the observed sea-level rise between 1961 and 2003. The extraction of groundwater for irrigation and home and industrial use, with subsequent run-off to rivers and eventually to the oceans, represents the bulk of the contribution. It would be even worse if we weren't also locking up lots of water from rivers behind dams like the Hoover Dam."

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Worse? (2, Insightful)

Anonymous Coward | more than 2 years ago | (#40075987)

It would be even worse if we weren't also locking up lots of water from rivers behind dams like the Hoover Dam

Even worse? Like a couple more millimeters! Evacuate NYC!

Re:Worse? (0)

MyLongNickName (822545) | more than 2 years ago | (#40076069)

0.77mm per year over 42 years. So the person who modded you up wasted a mod point.

Re:Worse? (3, Insightful)

jdgeorge (18767) | more than 2 years ago | (#40076091)

It would be even worse if we weren't also locking up lots of water from rivers behind dams like the Hoover Dam

Even worse? Like a couple more millimeters! Evacuate NYC!

According to my calculations, 1.8 mm per year means about 3.5 inches in the 50 years they're talking about. They're not laughing in the Maldives, Florida or a number of low-lying coastal regions, such as, oh, yeah, Manhattan.

Re:Worse? (5, Interesting)

Anonymous Coward | more than 2 years ago | (#40076189)

Except no one looks back at the 20th century and remembers the great sea level disaster. The sea rose 7" over the 20th century, with zero acceleration in rate until the satellites came online, and no one noticed for 90 years. (Which obviously proves satellites cause sea level rise. )

If you continue to just use the geologically stable tide gauges (as was used before satellite data became available) the rate of sea level change hasn't changed in 100 years.

Re:Worse? (4, Funny)

Chrisq (894406) | more than 2 years ago | (#40076241)

The sea rose 7" over the 20th century, with zero acceleration in rate until the satellites came online, and no one noticed for 90 years. (Which obviously proves satellites cause sea level rise. )

So the Chinese are the good guys for blowing up satellites after all.

Re:Worse? (1)

wonkey_monkey (2592601) | more than 2 years ago | (#40076731)

Satellites? Please. Everyone knows this has been caused by the steady decline in pirate activity over the last two centuries, which has even been enough to more than compensate for the lack of displacement caused by their boats!

Re:Worse? (1)

Anonymous Coward | more than 2 years ago | (#40076333)

Except no one looks back at the 20th century and remembers how all the spoiled people demanded to own the beaches, mostly because they didn't. And now we've got a supreme court decision that says they do.

Hilarious, because the spoiled californian who came to texas and challenged the law actually went "whoops I didn't mean that" when he discovered that once he personally owns the beach, he has to buy his own sand to put on it, and now he's gone and broken the toy for everyone else in the US. All that beachfront property became mostly worthless overnight except to the megarich who can afford to buy the sand for it.

Re:Worse? (5, Funny)

Dewin (989206) | more than 2 years ago | (#40076617)

(Which obviously proves satellites cause sea level rise. )

Well, there is one particular satellite [wikipedia.org] that has been well known to cause sea levels to rise quite significantly, so I think you might be on to something here...

Re:Worse? (4, Funny)

Baloroth (2370816) | more than 2 years ago | (#40076721)

Well, there is one particular satellite [wikipedia.org] that has been well known to cause sea levels to rise quite significantly, so I think you might be on to something here...

Well, yes, but not globally.

Re:Worse? (1, Insightful)

phantomfive (622387) | more than 2 years ago | (#40076473)

Don't forget geological effects. Continental drift can be as much as 50mm a year. Then you have places like this [sfgate.com] , where the annual change is measured in feet, not millimeters.

When it comes to coastal issues, a 3.5 inch sea rise in 50 years is relatively small.

Re:Worse? (5, Informative)

BMOC (2478408) | more than 2 years ago | (#40076483)

Coral Atolls cannot suffer from sea level rise, they are the result of life living near the surface creating a deposit that itself builds the atoll. The Maldives will never suffer from gradual sea level rise. Charles Darwin himself discovered how Atolls remain above water. If these islands were bedrock, you might be right, but they're not. Atolls are essentially floating islands.

http://www.pacificdisaster.net/pdnadmin/data/original/The_dynamic_response.pdf [pacificdisaster.net]

Results show that 86% of islands remained stable (43%) or increased in area (43%) over the timeframe of analysis. Largest decadal rates of increase in island area range between 0.1 to 5.6 hectares. Only 14% of study islands exhibited a net reduction in island area.

Despite small net changes in area, islands exhibited larger gross changes. This was expressed as changes in the planform configuration and position of islands on reef platforms. Modes of island change included: ocean shoreline displacement toward the lagoon; lagoon shoreline progradation; and, extension of the ends of elongate islands. Collectively these adjustments represent net lagoonward migration of islands in 65% of cases.

Results contradict existing paradigms of island response and have significant implications for the consideration of island stability under ongoing sea level rise in the central Pacific.

First, islands are geomorphologically persistent features on atoll reef platforms and can increase in island area despite sea level change....

Re:Worse? (2)

aaarrrgggh (9205) | more than 2 years ago | (#40076203)

Well... Hoover Dam doesn't have that much water behind it anymore... But if it was filled to capacity from current levels ocean levels would decrease by 0.077mm. The horror!

Really? (5, Insightful)

Dmritard96 (1268918) | more than 2 years ago | (#40076003)

"It would be even worse if we weren't also locking up lots of water from rivers behind dams like the Hoover Dam." - Isn't the rate at which it leaves the lake the same as if the dam hadn't been there (with maybe the exception of evaporation...), just with a delay? My understanding was that dams affect latency but not throughput...

Re:Really? (2)

Drethon (1445051) | more than 2 years ago | (#40076049)

I think the water behind dams may have a higher evaporation rate. Though my understanding of the Colarado river and such, the bigger issue is that diversion for irrigation is leading to the river essentially drying up before it reaches the ocean.

Re:Really? (0)

rickb928 (945187) | more than 2 years ago | (#40076247)

A lot of the Colorado River 'evaporates' into Arizona etc. before it trickles into Mexico. We call it 'water supply'.

I know. I drink some of it every day, and evaporate it into the local aquifers, shallow though they are. And we drink it again and again before it eventually evaporates from my pool (or others, or our tiny little lawns) and goes elsewhere.

You may want to refer to this 'evaporation' as 'use'.

Re:Really? (2)

saveferrousoxide (2566033) | more than 2 years ago | (#40076101)

Not quite. Dams actually meter the water out at a specific rate, but that rate is typically less than what would flow naturally. Hence, the giant wall of water being held back. When it rains, the level goes up and when it doesn't it (relatively slowly) drains out. If it rains too much, there is a mechanism to release more water in a controlled flow so it doesn't spill over the top. If the Hoover dam wasn't there the Colorado river would be much wider and deeper at that point, flooding a lot of developments that have cropped up since it was put in.

Re:Really? (1)

Dmritard96 (1268918) | more than 2 years ago | (#40076125)

Right, but doesn't the average still need to be the same (again neglecting evaporation)? otherwise the lake would eventually be growing or shrinking...

Re:Really? (1)

Qzukk (229616) | more than 2 years ago | (#40076379)

(again neglecting evaporation)?

You're also neglecting reuse of the artificial lake's water. Most of them are used as reservoirs for irrigation or public water supply.

Re:Really? (3, Insightful)

TapeCutter (624760) | more than 2 years ago | (#40076449)

They claim the ocean is rising due to increased runoff from human activity, yet it's well known that most of the worlds major rivers are a shadow of their natural self by time they reach the ocean (if they get there at all). Perhaps stormwater drains are taking up the slack, but for the moment I'm left with two credible claims that on the surface appear to directly contradict each other?

Re:Really? (1)

tmosley (996283) | more than 2 years ago | (#40076511)

Perhaps increased evaporation from human use causes greater rainfall at sea, leading to the rise?

Re:Really? (1)

progician (2451300) | more than 2 years ago | (#40076795)

Contradiction in nature simply means that the two or more process acts against each other, and it is up to us to predict what is going to happen at the end. If I push you from the one side and somebody else pushes you from the other you can measure easily who is actually pushing you harder by checking which direction do you move. If the sea level is rising, and we can't account for the extra volume of the water that means we don't know every factor yet so we need to look further.

Re:Really? (1)

Jeng (926980) | more than 2 years ago | (#40076119)

The volume behind the dam is going to remain fairly steady.

Re:Really? (0)

progician (2451300) | more than 2 years ago | (#40076181)

Depends. If you have a buffer in a system, and you're investigating the amount of information processed by the end-point, you'll always find that you're missing a full buffer data between input and the output since the buffer has been set up. Of course, after the dam is full, the rate of water flow will be restored to the original state (sort of), so the global water re-cycling rate will be restored too. However, when you release the buffer, you need to release it with a higher rate than the water-flow is originally (otherwise the dam would not release extra volume by definition), and if we assume that the water re-cycling rate is around 100% in its natural cycle (let's say, annually) than the additional volume released during the period of flushing the dams, the water-level should rise provided that the re-cycling rate do not change.

sea levels rising for thousands of years (4, Interesting)

rubycodez (864176) | more than 2 years ago | (#40076009)

The sea levels have been rising since the last ice age, and for much of that time much faster than now. The volume of the ocean changes for many reasons. Those lands that are essentially at sea level are doomed anyway, no point in the sob stories of displaced natives as their land would be covered even without any alleged actions by man, if not now then in next few centuries. Better they move now before their population grows even bigger and more people are affected.

Re:sea levels rising for thousands of years (2)

WillAdams (45638) | more than 2 years ago | (#40076099)

This also includes some prime U.S. real estate as well --- I for one would be very sad to lose the Outer Banks (North Caroline barrier islands), and losing them would have negative implications for the North Carolina coast during hurricane season.

This does create some interesting questions:

  - could one divert water from the outflow of major rivers for and pump it up-hill to a reservoir which would replenish ground water?
  - should cooling systems for nuclear power plants, rather than pump all water immediately back into a river pump it into a reservoir?
  - should water facilities which take up ground water be required to return said water to a (different) local reservoir instead of putting it into a local river or stream?

Re:sea levels rising for thousands of years (4, Insightful)

Penguinisto (415985) | more than 2 years ago | (#40076503)

re. Outer Banks: I don't think you'd lose their buffer characteristics overnight; you'd have to wait until they were under something like 30' of ocean. They're still there and able to temper/stop any storm surge from hurricanes.

re. aquifers: why would you want to pump it anywhere? You fill the aquifer with the water that is still uphill by damming it up while it's up there - it's less energy-intensive that way. Problem is (if Oregon is any indication), building a dam is politically impossible these days.

re: ground water: A big problem is that some aquifers (e.g. the Ogallala) span multiple states. Who gets to pay for, manage, and regulate that?

One more bit: In most of the Western US, water is a very touchy subject. Water rights and ownership is separate from property and mineral rights (e.g. you can often own the dirt, but not the water to be found in, under, or on it). Except for parts of Oregon and Washington, you will find water rights, ownership, and laws to be a byzantine and brain-hurting mess to sort through. That it works at all without physical violence breaking out is a miracle.

Re:sea levels rising for thousands of years (0)

Anonymous Coward | more than 2 years ago | (#40076519)

Meanwhile, marine creatures are talking about the recent "air level rise" and are trilled with the prospect of gaining the Outer Banks.

Since the ice age? (-1)

Anonymous Coward | more than 2 years ago | (#40076163)

So, let me get this straight, if you take the sea level at the last ice age, when the water was all trapped in ice as your starting point, and compare to later, when the ice has melted, the sea level has risen from all the melted ice?

http://www.giss.nasa.gov/research/briefs/gornitz_09/

And you hypothesize that there is an infinite amount of ice that would continue this trend, doing the same thing and ultimately doing the same damage we're doing?

So if I shoot you, that's OK, because time would have killed you anyway? I think you're doing three things: 1) cherry picking your data points, 2) extrapolating the graph not the underlying data it represents, and 3) using irrational logic.

Re:Since the ice age? (2)

tomhath (637240) | more than 2 years ago | (#40076529)

It's called Post-Glacial Rebound [wikipedia.org] , the land was pushed down by the glaciers, it's still rising now that the ice is gone. And since water runs down hill the Great Lakes (among others) are draining.

Re:Since the ice age? (4, Interesting)

The Mighty Buzzard (878441) | more than 2 years ago | (#40076553)

I'm pretty sure he was saying that it always continues warming from one ice age until we hit the next. Whether we melt all the ice a hundred years sooner is unimportant in both the short and long term. In the medium term you have a bunch of people pissing and moaning because they got stuck with the changing real estate rather than their great-grandkids.

The ice is going to melt. We are going to have another ice age. There's not a damned thing anyone can do about it and it's probably not going to happen in my lifetime, so why should I give a fuck?

Re:sea levels rising for thousands of years (-1)

Anonymous Coward | more than 2 years ago | (#40076225)

They're mostly brown or yellow. Fuck 'em, I say.

oh (-1)

Anonymous Coward | more than 2 years ago | (#40076025)

oh

Makes you think doesn't it. (0)

Anonymous Coward | more than 2 years ago | (#40076029)

Imagine how much Facebook contributes to sea level changes.

Re:Makes you think doesn't it. (1)

santax (1541065) | more than 2 years ago | (#40076071)

Hmmz, haven't calculated that, but I did calculate that Facebook is adding about 90% shit to the internet. Leaving 9% for twitter and 1% for 4chan. An outcome that suprised me to be honest. I would have expected twitter to be good for at least 11%.

Re:Makes you think doesn't it. (1)

Chrisq (894406) | more than 2 years ago | (#40076261)

Hmmz, haven't calculated that, but I did calculate that Facebook is adding about 90% shit to the internet.

That's proof. Think of all the water used to flush that shit away.

Re:Makes you think doesn't it. (1)

rickb928 (945187) | more than 2 years ago | (#40076305)

You must be using Sense. Your Friend Stream combines Facebook and Twitter, so you get most of your shit in one stream.

The rest of the shit is from that damned Yahoo! gizmo you installed. Same as your PC. Keyword 'mail'.

Re:Makes you think doesn't it. (1)

Dishevel (1105119) | more than 2 years ago | (#40076487)

While Facebook does indeed contribute the vast majority of shit to the "series of tubes" 4chans shit is oz for oz much more potent.

Preventing water from returning to the sea (1)

Compaqt (1758360) | more than 2 years ago | (#40076039)

I had always thought it was bad to prevent water from returning to the sea, as in:

-damming it up
-sucking it out of rivers before the river reaches the sea

It seemed to me that that would be upsetting ecological balances.

But now this seems to contradict that.

Actually, now that I think about it, it makes sense. The water from underground aquifers shouldn't to the ocean. It should go back into the ground.

This is one of those weird anti-environmental = environmental things (like some people who believe in AGW also now believe in nuclear as a solution).

Re:Preventing water from returning to the sea (0)

rickb928 (945187) | more than 2 years ago | (#40076389)

"always thought it was bad to prevent water from returning to the sea"

I dare you to try. You may delay it, but the water will return to the sea. No matter what clever little trick we try, unless we bottle it and hide it in salt caves.

But the water will eventually go where it goes. Ask any homeowner who's had the pleasure of a leak. Water extracted from an aquifer will go around and some will take its place and replenish the aquifer. If you draw too much out, sure, the aquifer will be depleted, but rain wil usually refill it.

When I lived in Maine, I understood water fairly well. My hometown is served by two poinds, which are owned entirely by the water district, both fed by aquifers, clear enough to look 150 feet straight down from the air and see the bottom. Better water than you can buy. When I was living further south in Maine, I had the opportunity to visit someone who had a well dug stupendously deep (+600ft) and drank water that flowed from an aquifer that fed the Poland Spring - I was drinking their well water after it got by the pipes that otherwise extracted it to be sold. this went further west and spilled into the lake that supplied the city I lived in at the time, again water others would pay for, except that this lake had boats with motors in it, and still a few camps that had not diverted their waste asd required by law. change comes slowly.

Good water I appreciate. Out here in Arizona, too much calcium and chlorine. Tastes like bath water or public pool. Bleagh.

Wrong Science (0)

mrops (927562) | more than 2 years ago | (#40076711)

To be honest, its science like this that does harm to global climate change initiatives.

I can't see humans drinking and then pissing changes ocean levels. Yah, I am exaggerating, but that is what we are saying. The same water that had got there anyway got routed and used, how does that explain sea level rise!

Dam Baby, Dam! (2)

PrescriptionWarning (932687) | more than 2 years ago | (#40076055)

So we just need more dams to fix this right, time to put those beavers to work!

Re:Dam Baby, Dam! (0)

Anonymous Coward | more than 2 years ago | (#40076127)

Large-scale nuclear fusion would also fix this. Turning water into helium, oxygen and energy.

Re:Dam Baby, Dam! (1)

TapeCutter (624760) | more than 2 years ago | (#40076609)

I think you mean hydrogen, Eventually Earth will be like Venus, the Sun's rays having split all the water molecules in the upper atmosphere and sent the H2 spinning off into space. On the scale your planning people will be busrting into flames in a few thousand years. OTOH you will have averted countless ice ages over the next billion years or so.

If we do the right thing and burn the H2 then there won't be any change in the total amount of water in the system, save for what is in H2 storage tanks.

Re:Dam Baby, Dam! (4, Funny)

dkleinsc (563838) | more than 2 years ago | (#40076273)

... time to put those beavers to work!

Must ... resist ... obvious ... joke

Dam! (0)

Anonymous Coward | more than 2 years ago | (#40076073)

That remark regarding influence of the (Hover) dam is rather uninformed: the water mass trapped behind dams world wide is negligible. Obviously, I leave the math as an exercise for the reader.

Re:Dam! (1)

houstonbofh (602064) | more than 2 years ago | (#40076133)

That remark regarding influence of the (Hover) dam is rather uninformed: the water mass trapped behind dams world wide is negligible. Obviously, I leave the math as an exercise for the reader.

So is the amount of sea level rise. But while two wrong do not make a right, to negligables do make a headline.

Re:Dam! (1)

Dcnjoe60 (682885) | more than 2 years ago | (#40076343)

the water mass trapped behind dams world wide is negligible

I bet if you ask the people of Johnstown, PA or anywhere else that a dam has collapsed, they would have a different point of view.

Re:Dam! (1)

rickb928 (945187) | more than 2 years ago | (#40076471)

Might want to ask the fish also. they see it as a major stumbling block. Or did, when they were around, but the Hoover dam is a substantial impediment to their reaching those spawning grounds, so they, well, gave up.

Other smaller dams did as much damage. Atlantic Salmon didn't need the extra tress, but this contributed to their becoming rare as they are now. I've caught my last Atlantic Salmon quite some time ago. Somehow the Pacific varieties have survived. Apparently the Japanese and Norweigans don't drive over there and fish them out.

Re:Dam! (3, Funny)

lxs (131946) | more than 2 years ago | (#40076167)

I have a hard time picturing how a hover dam manages to trap any water. Won't the water simply flow underneath the dam?

Re:Dam! (1)

fprintf (82740) | more than 2 years ago | (#40076521)

Bedrock is fairly impermeable.

Re:Dam! (1)

Chrisq (894406) | more than 2 years ago | (#40076277)

That remark regarding influence of the (Hover) dam is rather uninformed: the water mass trapped behind dams world wide is negligible.

Quite right. If a dam is hovering then the water can leak out from underneath.

That's why geologists now call this epoch (3, Insightful)

fredrated (639554) | more than 2 years ago | (#40076075)

the 'Anthropocene', we have changed the surface of the earth so much.

Re:That's why geologists now call this epoch (0)

Anonymous Coward | more than 2 years ago | (#40076695)

Geologists don't. Malthusians do.

I don't buy it (4, Funny)

Waffle Iron (339739) | more than 2 years ago | (#40076077)

This is obviously just another cry of "the sky is falling" from a bunch of alarmists pushing their anti-freedom agenda.

There's no credible evidence that this so-called "ground water" exists at all. Look down at your feet: The ground is made out of dirt. How do they supposedly turn all this dirt into water? Answer: They can't. Dirt is black, water is clear. You don't get one from the other. It's just common sense, people.

There's nothing to see here. Move along.

Re:I don't buy it (0)

Anonymous Coward | more than 2 years ago | (#40076141)

This is obviously just another cry of "the sky is falling" from a bunch of alarmists pushing their anti-freedom agenda.

There's no credible evidence that this so-called "ground water" exists at all. Look down at your feet: The ground is made out of dirt. How do they supposedly turn all this dirt into water? Answer: They can't. Dirt is black, water is clear. You don't get one from the other. It's just common sense, people.

There's nothing to see here. Move along.

I actually know people who would actually believe what you said and get outraged over it and bitch about the "Liberals" and their "Agenda" about ground water.

You could have a brilliant career writing for Talk Radio and Fox News - if you don't already.

Re:I don't buy it (2)

Dishevel (1105119) | more than 2 years ago | (#40076543)

You actually know that teacher in NC?

Re:I don't buy it (0)

Anonymous Coward | more than 2 years ago | (#40076205)

Dirt is black

On a completely unrelated topic... Where the hell do you live that has black dirt? A volcanic crater?

Unless it's black by night. But then again... by night water is also black... OMG! Ground is water by night! And Liberals are sending it to the ocean! They are actually destroying american soil!

Re:I don't buy it (2, Funny)

pr0nbot (313417) | more than 2 years ago | (#40076215)

Brother, your indignation is most righteous! However, you must remind yourself of the Scripture!

Genesis 1:6 -- 'And God said, "Let there be a firmament in the midst of the waters, and let it separate the waters from the waters." 7 And God made the firmament and separated the waters which were under the firmament from the waters which were above the firmament.'

Let us not be the ones to disrupt the wisdom of His divine order by moving the waters from one side of the firmament to another!

(I'll work on a Raëlian interpretation next.)

Re:I don't buy it (-1)

Anonymous Coward | more than 2 years ago | (#40076493)

Sarcasm is for the weak of mind.

Re:I don't buy it (0)

Anonymous Coward | more than 2 years ago | (#40076517)

This is even funnier when I imagine Foghorn Leghorn saying this.

Unsustainable. (3, Funny)

Hatta (162192) | more than 2 years ago | (#40076083)

So how long can we use surface water at this rate before we run out?

Re:Unsustainable. (1)

Jeng (926980) | more than 2 years ago | (#40076193)

The question should be "So how long can we use fossil water at this rate before we run out?"

This is what they are talking about.

http://en.wikipedia.org/wiki/Fossil_water [wikipedia.org]

This is the one we should worry about in the US.

http://en.wikipedia.org/wiki/Ogallala_Aquifer [wikipedia.org]

About 27 percent of the irrigated land in the United States overlies this aquifer system, which yields about 30 percent of the nation's ground water used for irrigation. In addition, the aquifer system provides drinking water to 82 percent of the people who live within the aquifer boundary.

Re:Unsustainable. (1)

hherb (229558) | more than 2 years ago | (#40076229)

If we apply current economic wisdom, infinitely. The more we use water, the more it will become... until all surface is covered by water for all to enjoy.

Re:Unsustainable. (0)

Anonymous Coward | more than 2 years ago | (#40076313)

Funny... I thought the current economic wisdom is to Print more Water to shore up the stock market (Q-water-tative Easing 1, 2, & 3).

Re:Unsustainable. (1)

dkleinsc (563838) | more than 2 years ago | (#40076691)

Well, obviously, trickle-down economics would work.

Re:Unsustainable. (1)

dkleinsc (563838) | more than 2 years ago | (#40076255)

Depends where you are: The southwest US is already having serious water problems, while all the Great Lakes cities are doing just fine in terms of overall supply. It bothers me that anyone would think that growing turf grass in a desert was a good idea, but that is in fact what we're doing.

Re:Unsustainable. (0)

Anonymous Coward | more than 2 years ago | (#40076613)

In India, not very long at all [nasa.gov]

Re:Unsustainable. (0)

Anonymous Coward | more than 2 years ago | (#40076729)

Un-obligatory [xkcd.com]

really? (0)

Anonymous Coward | more than 2 years ago | (#40076207)

Idea if you took a huge amount a water out of the ground and say that acted like coolent for the earth would it not over time when you take a lot heat up the earth thus expand the rate at which the poles melt as well?

Re:really? (0)

Anonymous Coward | more than 2 years ago | (#40076505)

What the fuck is a 'coolent'?

Re:really? (0)

Anonymous Coward | more than 2 years ago | (#40076667)

"coolent" is an indicator that someone has turned off their spelling checker.

Your question in an indicator of someone who places more importance in form than function. People who are more interested in reading the messages will understand that this is simply a spelling mistake, know exactly what is meant and carry on without making an issue of it.

Oh, wait, am I responding to Sheldon Cooper? What an honour.

The relevant part (1, Insightful)

Corson (746347) | more than 2 years ago | (#40076239)

The relevant part in this shocking news is "0.77 millimeters per year", not "42% of recent sea level rise". How on earth does one measure 0.77 mm per year? When I watch the waves breaking against the sea shore this seems so far fetched.

Re:The relevant part (2)

spectrokid (660550) | more than 2 years ago | (#40076631)

it is called "averaging". If you have a hole year to do it, you can do a fucking lot of it.

Re:The relevant part (1)

wes33 (698200) | more than 2 years ago | (#40076781)

You point is intriguing. How many "hole years" are in a century?

Re:The relevant part (3, Informative)

skine (1524819) | more than 2 years ago | (#40076753)

The older method, still in use, is to use tide gauges. Basically, these are long cylinders placed below the water level, and thus are able to remain mostly unaffected by waves. Hundreds, if not thousands of measurements are taken electronically every day, and these measurements give a good measure of the water level at that location over the course of the year. According to Wikipedia, there are over 1700 tide gauges being used worldwide, so you wind up getting a good average of the worldwide sea level.

The newer method is to use satellite altimeters which use radar to give accurate measures of the altitude of the land or sea below them.

The two methods combined give millions of data points over the course of a year, and scientists have been taking measurements since the mid-1800's.

Despite what one may think, it's not quite like there are scientists on beaches around the world placing a new toothpick in the sand for each and every wave.

It could be... (1)

Troyusrex (2446430) | more than 2 years ago | (#40076253)

I was thinking that this might be mathematically silly as even though .77 millimeters per year isn't much the surface area of the ocean in VAST (131.6 million miles). But a quick calculation on Wolfram Alpha shows it'd only take 69,300,000 gallons of water or less than enough water to fill a supertanker. That sounds reasonable to me.

Re:It could be... (1)

Dynedain (141758) | more than 2 years ago | (#40076469)

Something seems off there.

If the raise described is the volume of one supertanker, that means 1 supertanker filled with water would (fully dispersed) raise worldwide ocean levels by .77mm.

Sure, less weight for oil than water, so the total displacement for working supertankers is lower, but still... with the armada of supertankers around the world, this should be measurable effect in total.

Re:It could be... (0)

Anonymous Coward | more than 2 years ago | (#40076791)

I absolutely love this. Ocean level rise measured to such a fine degree that we might only be measuring the displacement of all the freighters, oil tankers, super cruise ships and oil drilling platforms that we've placed on the ocean surface in the last couple of decades.

What would be the effect of building a floating city? Right, the ocean level would rise even more and that would create more of a demand for floating cities to give people places to live as the ocean level rises from adding floating cities to the mix.

I guess we'd better haul all them things out of the water before we flood any more valuable land. I'd suggest building that bridge from Asia to Alaska so we could move everything by rail but then the ocean level would rise from the displacement of the footings for the bridge.

Oh, the irony of it all.

Dams (0)

Anonymous Coward | more than 2 years ago | (#40076271)

Umm, by continuity, the water is still flowing through the dam. If dams fully stopped the flow of water, the water would eventually overflow. We dam it to extract work from the water level height.

Re:Dams (1)

Jeng (926980) | more than 2 years ago | (#40076423)

There is an volume that is locked behind the damn.

There used to be a volume of water locked away in deep aquifers which do not get replenished.

If the damns let loose then that volume of water behind the damns would help increase the sea level, much in the same way that the water that used to be in deep aquifers is increasing the sea level.

Sea Level Rise (0)

smitty_one_each (243267) | more than 2 years ago | (#40076283)

Sea level rise,
A 5-o'clock shadow surprise.
For grooming and the wise,
We continue to despise.
Burma Shave

Human water [mis]use? (1)

Polizei (1782856) | more than 2 years ago | (#40076293)

I think that it's not the regular water use that's the problem, but the *misuse* - mainly manual underground water extraction...
Normally, water that has come to the ocean will eventually return to the ground in the form of rain, rivers will be full, etc...
Manually extracted water could not be returned that easily to the source. I'm not aware of the way that rivers are formed, or if/how they refill but this doesn't seem to be the problem in this case.
And, uhm, yes. The ocean level is rising since I remember. Deal with it.

I need help. (0)

Anonymous Coward | more than 2 years ago | (#40076299)

Can someone explain to me how we can possibly measure the level of the World's oceans to within a tenth of a millimeter?

Frankly, when I consider the effects of temperature, wind, tides, currents... I find it hard to believe that we can come within a decimeter or two of accuracy.

One tenth of a millimeter?

Confused (1)

IndigoDarkwolf (752210) | more than 2 years ago | (#40076353)

Could someone explain this part to me:
"It would be even worse if we weren't also locking up lots of water from rivers behind dams like the Hoover Dam."

I get that destroying dams would cause greater fluctuations in water flow rates downstream. Over the long term, however, how would destroying dams cause a net increase in annual water flow rates? Are we actually letting out less aggregate water than comes in, causing dam lakes to actually grow larger each year and dooming them to inevitably flood over the dams creating them? I thought dams merely regulated water flow after building up a large reservoir to spin the turbines for electricity generation.

Re:Confused (0)

Anonymous Coward | more than 2 years ago | (#40076451)

It wouldn't in the long term, but over the course of the last ~100 years the sea level increase that would have happened had we not built large dam systems would have been greater. Stockpiling water behind dams has offset some of the released ground water. It won't be sustainable to keep dam building up at a sufficient rate to counter-act groundwater usage / glacial melting / thermal warming for every though.

Hoover dam (1, Insightful)

spectrokid (660550) | more than 2 years ago | (#40076371)

Ok, smartasses: the Hoover dam contains 37 cubic kilometer of water. The oceans 1.3 BILLION. This argument is ridiculous.

Re:Hoover dam (4, Interesting)

blueg3 (192743) | more than 2 years ago | (#40076489)

The oceans are also much deeper than a few millimeters. Total volume isn't really meaningful here.

One millimeter across the world's oceans is about 350 cubic kilometers. So if the contents of the Hoover Dam flowed to the ocean, they would (ostensibly) raise the sea level by ~0.1 mm.

Re:Hoover dam (0)

Anonymous Coward | more than 2 years ago | (#40076507)

Now how many other dams are there.

Comedy by the Confussed (0)

LifesABeach (234436) | more than 2 years ago | (#40076387)

Nature Geoscience must be hard up for cash, its editorial staff are all on vacation, or a combination of both. I would think that a simple review of all known damns holding capacities versus the loss of ice would end this comedy by a once respected periodical. As a minor note to those, like me, that are the unwashed, the early 1980's was the last time earth had normal weather conditions. Good times, good times indeed.

Anyone else confused? (5, Insightful)

Anubis IV (1279820) | more than 2 years ago | (#40076399)

...by this comment at the end of the summary?

It would be even worse if we weren't also locking up lots of water from rivers behind dams like the Hoover Dam.

I don't see why this matters much. If you released all of the dammed water, you'd have a one-time increase in ocean levels. So what? Dams control rivers, sure, but those rivers are still flowing and have been this entire time. Surely the throughput from that river over a relatively short period of time is far more significant than any amount of water dammed along that river.

To me, that statement is as silly as, "We'd have even more cars on the road if we weren't locking some of them up at red lights and intersections."

More news for AGW alarmists (2, Insightful)

bhlowe (1803290) | more than 2 years ago | (#40076403)

How is this news for nerds? Hell, there is probably a good percent of the slash dot crowd that doesn't even bathe regularly... Really, the alarm over AGW is really not tech related unless any of the following: Its a _real_ crisis (just one little drowning?), 2. something that can be done, 3. or it is actually interesting in a nerdy kind of way...

If this were a real concern, beachfront property prices would be falling. Islands would be littered with For Sale signs. 1 mm over many decades doesn't mean squat..

Well, obviously (2)

Tifer (2644417) | more than 2 years ago | (#40076421)

We should scoop up millions of gallons of seawater and blast it into space. Water on the moon, indeed!

extraction of groundwater (1)

swell (195815) | more than 2 years ago | (#40076475)

Photos from orbit will show earth looking more and more like a prune with all that sucking of water, oil & gas from below even as the surging tides flow in to fill the wrinkles that appear. The earth will turn in on itself and shrink like a raisin with the remaining ice caps to look like a tasty sugar frosting. The end will come when a giant spoon scoops up the planet and it is crushed by immense teeth and devoured in a potent mix of saliva and digestive juices. Or maybe I'm letting my imagination carry the concept too far...

Could be other causes, too (3, Insightful)

Dcnjoe60 (682885) | more than 2 years ago | (#40076477)

There are other causes besides just melting ice caps and expanding water and man made activities. For instance, the Great Lakes in the US are rising. As they rise, the more and more water runs out of them and eventually finds its way to the sea. There are other large bodies of water with similar geological forces in play that have nothing to do with man's activity.

It seems like places like Venice were worried about rising water levels long before 20th century man started irrigated cropland and the like. I am not a climatologist or anything like that but it seems like an awfully simple model that only looks at melting ice, warming water and the rest is because of people.

Just so we are clear here, (1)

rickb928 (945187) | more than 2 years ago | (#40076491)

It's our fault, we are usign too much water and upsetting the balance.

Bad humans! Be gone!

Riiiiiight...

Stop peeing in the ocean! (1)

Snaller (147050) | more than 2 years ago | (#40076497)

Damn it people, how often do I have to tell you!

Nonsense (0)

Anonymous Coward | more than 2 years ago | (#40076513)

Hogwash. Ground water is replenished from rain, snow, run off, etc. etc. All this hullabaloo about warming, oceans rising, blah blah blah is all naturally occurring. It's cyclical. Get over it. I grew up in a time when the environmental lobby was claiming that we were going to cause an ice age. It's all a bunch of bullshit. Humans are really bad however, at managing water resources for our own use.

I'll tell you what though - humans are making the environment more toxic. Now that's something to be actually concerned about and to put resources behind to clean up.

How? (4, Insightful)

Just Some Guy (3352) | more than 2 years ago | (#40076523)

It would be even worse if we weren't also locking up lots of water from rivers behind dams like the Hoover Dam.

How would that be? Dams don't make the water go away. Over time, the amount of water going into the reservoir equals the amount leaving, or else the water levels would either drop or overflow the dam. The only significant change I'd see is that dams increase the surface area of the water and would therefore raise evaporation, so some of the water that would normally go downstream would turn into atmospheric moisture instead. For global warming purposes, that's probably not a good thing. But would it actually have a non-negligible effect on ocean levels?

Re:How? (3, Informative)

Sir Realist (1391555) | more than 2 years ago | (#40076743)

I wondered this too... so I went and read the linked original article, which quite clearly states:

"Artificial reservoirs, such as the Hoover Dam on the Colorado River and the Three Gorges Dam on the Yangtze River in China, have the opposite effect, locking up water that would otherwise flow into the seas."

So your (and my) suspicions were correct; reservoirs don't make this problem worse, as the /. summary implies, but instead partially counteract it. Bad /. summary; no biscuit.

Land Mass Rising (1)

na1led (1030470) | more than 2 years ago | (#40076725)

I live in Maine, and the land mass here has been slowly rising. I guess I'll be safe, even if sea level rises.
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