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

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."

Comments

Worse?

[Anonymous Coward]

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?

[jdgeorge]

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?

[Anonymous Coward]

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?

[aaarrrgggh]

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!

Re:Worse?

[Chrisq]

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?

[Anonymous Coward]

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?

[phantomfive]

Don't forget geological effects. Continental drift can be as much as 50mm a year. Then you have places like this, 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?

[BMOC]

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

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?

[Dewin]

(Which obviously proves satellites cause sea level rise. )

Well, there is one particular satellite 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?

[Baloroth]

Well, there is one particular satellite 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?

[wonkey_monkey]

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?

[tompaulco]

Well... Hoover Dam doesn't have that much water behind it anymore
Having just last week spent 15 minutes flying over the lake in a commercial jetliner, I am inclined to disagree with you. In fact, it is listed as the 25th largest lake in the United states out of almost a half million lakes.

Re:Worse?

[TheSeventh]

That article you linked to is about coastal erosion, where the soil holding up the cliff was washed away into the sea. What does this have to do with sea rise or anything else? And it wasn't talking about the 'annual change' of that particular coastline, but the fact that several feet of the ground between a particular apartment building and the ocean was washed away in a few days.

Instead of being modded insightful, you should be modded Off-topic instead.

Re:Worse?

[phantomfive]

You aren't very polite, and you aren't good at doing basic research. If you'd spent five minutes on Google, you might have found this, which shows a change in the coastline of more than .5 meters over the last 146 years.

If you can't tell what continental drift and erosion has to do with sea-level rise, I don't know what to tell you. Continental drift means some coasts are growing an order of magnitude larger than the sea change. In other places, it is shrinking many times faster than sea level change.

Thus we see, for people who live on the coast, sea level rise of 1.8mm is a laughably small problem, when compared to the many other things they are facing.

Re:Worse?

[K. S. Kyosuke]

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.

It's obvious, they're just trying to protect Tibet from being flooded by evil water-wasting imperialist western countries.

Re:Worse?

[riverat1]

After the drought conditions that have existed in the Colorado River drainage for the past decade Lake Mead is currently only 57% of its normal water storage and that's up a bit from a couple of years ago. Lake Powell behind Glen Canyon Dam is only 72% of full. Together they are around 18 million acre-feet below their full capacity.

Re:Worse?

[Anonymous Coward]

I live in Florida on the water. I'm at 18.5' of elevation at the top of my bank and 22' at the lowest point of my door sill. At 1.8mm a year I'll worry about it in 3132.6 years when the water reaches the top of the bank...till then I'm just gonna chill with a cold one.

Re:Worse?

[nitehawk214]

While GP's "not much water" is an exaggeration, water use of the dam has been outpacing the rate it gets filled for decades now.

Soon it may not be able to produce power.

Basically irrigation and water use has grown quite a bit since the thing was built, and as the article suggests, a lot of this water ends up in the ocean.

Re:Worse?

[gx5000]

Venice comes to mind, and Mont St-Michel.....

Re:Worse?

[nitehawk214]

Actually I take back some of what I said, the lake is higher now than it was in the last 2 years (since the article I linked was written).

Levels are pretty good now, though that link doesnt show the outflow amount, and so doesnt say how much more water we use today.

Re:Worse?

[careysub]

You are probably thinking of Glen Canyon Dam, which is upstream from it. Lake Powell, behind Glen Canyon, was 150 feet below full pool 7 years ago with a fraction of its maximum volume, and is 50 feet below full pool now which makes it 2/3 full. Due to declining precipitation and increased water usage demands, some think that it will never reach full pool again.

Re:Worse?

[Sparticus789]

Right. The moon only affects North America. Everyone else gets to ignore it.

Re:Worse?

[FatdogHaiku]

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!

I think that's a false assumption in any case. We don't save that water forever, we use it somehow and then it continues on in the cycle of water we pump out of the ground. A reservoir only delays waters journey, it does not terminate the process. Once (or if) a reservoir is full the normal volume of outflow for the river needs to resume in some manner or the dam will overtop. If we were to pump the water into the ground (and leave it there forever) that might be different.

Re:Worse?

[FatdogHaiku]

(Which obviously proves satellites cause sea level rise. )

A statement of much gravity!

Re:Worse?

[hey!]

Except no one looks back at the 20th century and remembers the great sea level disaster.

Ever hear of Venice? Of course Venice is also subsiding, but seven inches on top of that has made a big difference to them.

The problem with sea level rise in the short term isn't that suddenly you're city is drowned every day of the year. It's with the increase in frequency with which rare catastrophic events occur. Every coastal city has a high water level below which flooding effects are marginal and above which they are catastrophic (e.g. a levee is overtopped). How close waters commonly come to that mark determines the impact of a marginal increase in sea level.

Cities like Venice or New Orleans which are already prone to flooding are certainly affected by an 18 cm rise in mean sea level, although that effect isn't necessarily seen every year. Boston on the other hand was built to withstand 3-4m tides and has never had a major flood from the sea, so the 18 cm rise in the 20th C. had zero effect on it. If at some point in the future sea levels rise by a meter or so, flooding might become a common event in Boston. At that point a further 18 a cm rise would be very expensive to deal with.

The effect of sea level rise is not linear, and it's not uniform throughout the world. The effect depends on how a city is constructed and situated.

Now as to "geologically stable tide guages", if you knew anything about surveying you'd know that rather begs the question. In any case you can get any result you want by arbitrarily throwing out data; *mocking* data you'd prefer not to exist doesn't count as an argument.

Re:Worse?

[couchslug]

Over that time it's still more economic to rearrange infrastructure than change anything else.

There is nothing on the coasts man can't afford to readjust/move/scrap in such a long timeline.

Re:Worse?

[Anonymous Coward]

They're not laughing in the Maldives

Actually, they are lauging. Sea level in the Maldives actually went down, but they really love the attention and money they can get from claiming that they're drowning.

Re:Worse?

[rthille]

The islands are created by the corals living in the waters. That limits the rate at which they can be "built" up to keep up with sea level rise. Also, other effects of rising CO2 levels, like warmer seas and ocean acidification may reduce the rate at which corals can build islands.

Re:Worse?

[Talderas]

This sounds retarded. I must read about it. Can you provide a little more detail so I can better investigate or even an article about it?

Re:Worse?

[TheSeventh]

Continental drift is not about coasts "growing" at all. Continental drift is exactly what it sounds like, and should therefore be self-explanatory. The "continents" are "drifting" (moving in other words). With some simple research, you would have found the definition if you couldn't deduce the meaning. US Geological Survey

Coastal erosion is where the "coasts" are "eroding" away. Ocean waves and currents are washing away soil and rock, moving the coastline (where the water meets the land) inward in some areas, outward in others, and both in some locations, which is also known as submersion.

Thus we see, your original post was wrong, and the article you linked to had nothing to do with the parent comment, or in fact, your own comment. The parent comment, and indeed this whole slashdot post, is about Sea Level Rise. Your comment was trying to compare continents moving, with an annual change of several feet, not in sea-level rise, but in coastline erosion. Literally 3 separate topics.

Lastly, your sentence:

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

is confusing as you're trying to say that a small amount of sea level rise doesn't matter very much towards coastal issues, which is the opposite of what this slashdot post is about. The sea level goes up, and the coastline moves inward. Not only from erosion (soil washing away), but because the water is moving further inland as it rises. Therefore, low-level areas will be submerged in water.

Sea level rise is not a relatively small coastal issue to an area like the the Maldives, which has an average ground level of 59 inches (the planet's lowest country). The sea rises, and not only does their coast disappear, but their whole country. That's kind of a huge issue.

Re:Worse?

[jc42]

Well, there is one particular satellite that has been well known to cause sea levels to rise quite significantly, ...

Well, yes, but not globally.

Perhaps not, but that's because it's only one satellite that can only be above one point on the Earth's surface at any given time. We've sent up thousands of smaller satellites that are scattered widely throughout a large spherical volume. When those little satellites' mass was below the Earth's surface, it pulled downward on the water; now that their mass is up above in a spherical arrangement, they're pulling up on the water from all directions. So clearly they are the cause of the slow rise in sea level worldwide.

Hey, you know that you're going to be reading variants of this argument from all over the interwebs now that the secret is out. So just remember that you read it here first. ;-)

Re:Worse?

[phantomfive]

You still can't see how a coastline growing or shrinking might be related to the topic of oceans rising? Or how it might be more important to a person actually living on the coast?

You have trouble seeing how someone's coastline disappearing at half a meter per year is more worrisome than a 3mm ocean level rise? Or how someone living in a subduction zone might be worried about their tectonic plate moving into the ocean at a rate of 50mm per year, more than they are about the 3mm ocean level rise? What is wrong with you?

Re:Worse?

[riverat1]

An acre-foot of water is one acre of area covered by a foot of water. It is a common unit in the United States for measuring large volumes of water. One acre-foot is equal to 1233.48184 cubic meters or 325851.4 US gallons. Hogsheads vary is size but if you take it to be 63 gallons then an acre-foot is about 5,172 hogsheads. Troy ounces is a measure of mass, not volume.

Re:Worse?

[Intrepid imaginaut]

Funny cos its true, in the last episode of Supernatural, the devil was haggling with the head of the leviathans, and at one point went like "you can have Canda, we get all the rest" "The whole United States?". Argh.

Re:Worse?

[michelcolman]

Maybe he meant "fluid troy ounce"?

Re:Worse?

[dwillden]

In case you really don't know, an acre foot is the amount of water that would cover one acre to the depth of one foot. This is equal to 325,851.43 gallons or 1,233,481.84 liters.

Or 5,172.25 hogsheads

Re:Worse?

[nanoflower]

I'm not the original poster but here is a link that seems related to what he was talking about:

http://www.chron.com/business/real-estate/article/Critics-fear-ruling-for-beach-homeowners-will-1717985.php

The gist is that in Texas people have the right to use any beach even if it puts them close to a house, up to the vegetation line. The problem is when the vegetation line is moved by a heavy storm. Apparently one woman ended up having her home move from being on private property to being on public property because of this vegetation line marking the end of the public beach.

Re:Worse?

[TheSeventh]

Coward. This was disproven, but why bother with facts, when you can't even spell?

They especially love the attention they get from Tsunamis, like the one in 2004 that wiped out quite a few of their islands. 57 islands were seriously damaged, 21 resort islands had to be closed, 6 were destroyed, and 14 had to be completely evacuated. Only 9 of over 1300 received no damage.

With an average ground height of less than 5 feet above sea level, I'm sure they'll be fine for at least a few more years.

Re:Worse?

[RenderSeven]

If at some point in the future sea levels rise by a meter or so, flooding might become a common event in Boston

Dont disagree with any of your post. But (maybe OT) the Boston Globe ran a front-page story a few years ago with a map of Boston showing it mostly under water. The article and caption said the map was a projection of the effects of sea level rise due to global warming (over 50 years IIRC). There was no other explanation of the map in the article. I finally found the source of the map in a research article that explained it better... yes it assumed worst-case sea level rise from GW, but coupled with a category 5 hurricane storm surge at peak high tide. A projection not taking GW into account showed little difference. It's an example of terrible reporting and fear-mongering, even though it was factual and possibly not even intentionally misleading. It's a good example of the need to be skeptical over any claims from either camp, and that skepticism isnt always 'mocking'.

I went to debunk your Venice claims but far as I can tell its not wrong. Venice is sinking faster, or slower, or not at all, due to aquifer depletion, water composition, foundation decomposition, or tectonics. All depending on which study you read last. But sea level rise does seem to be the significant factor far as I can tell. However I took the comment about "geologically stable tide gauges" as a reasonable caveat to avoid cherry picking data from differing inputs, something both pro- and anti-GW camps have been known to do.

Re:Worse?

[Crosshair84]

Except that all the doom and gloom about ocean acidification is junk science.

They decrease the pH in the lab by adding sulfuric acid to the water instead of the proper method of increasing the CO2 concentration. (Since it's easier to dump in a measured amount of acid and measure with pH strips rather than rig up the equipment to measure and maintain a high-CO2 environment.) That increased CO2 makes it easier for coral and other organisms to make calcium CARBONate for their shells. Where do you think that carbon to make their shells comes from? (dissolved carbon dioxide, bicarbonate ions, carbonate ions) The carbon is what is in short supply in seawater, 441ppm calcium vs 90ppm carbon, so increasing the amount of CO2 in the oceans increases the amount of carbon, meaning coral can grow faster because the process has become more efficient because of additional carbon, more than offsetting any damage to their shells.

You also have the inconvenient fact that there are past times in Earths history where CO2 levels were 10 times higher than they are now, yet coral still grew and thrived. The pH of seawater is around pH 8.2. Pure water is pH 7.0, and clean rainwater is pH 5.6. Also, seawater is a highly buffered solution. (Translation: It can take up a huge amount of dissolved inorganic carbon without significant effect on pH.) There is not the slightest possibility that the oceans could approach the neutral pH of pure water even if all the fossil fuel in the world were burned, so all talk of ‘acid’ oceans is pointless.

Re:Worse?

[Sparticus789]

I believe everything I see on TV. Especially that "Ancient Aliens" show. Kurt Vonnegut is brilliant for figuring that out.

Re:Worse?

[Mindcontrolled]

Oh, yeah? Just one link, 30 sec of googling:

Using a 30-tank experimental system, we manipulated CO2 levels to simulate doubling and three- to fourfold increases [Intergovernmental Panel on Climate Change (IPCC) projection categories IV and VI] relative to present-day levels under cool and warm scenarios. Results indicated that high CO2 is a bleaching agent for corals and CCA under high irradiance, acting synergistically with warming to lower thermal bleaching thresholds.

Re:Worse?

[Firethorn]

enough water to cover 1 acre with 1 foot of water. It's around 326k gallons. It's a more useful measurement when you're dealing with dam levels and watering fields.

Re:Worse?

[Cramer]

Perfectly "clean" rainwater should have a pH close to 7.0 -- being pure water. 5.6 is bordering on "acid rain". (I'll check my rainwater sisterns, but they've had a long time to settle.)

Yes, sea water is highly buffered. However, that buffer is not instant. Look at the small scale in my (freshwater) aquariums... they have carbonate buffers in there (a lot of it, in fact -- aragonite and commerical buffers) and the pH can still dip below 6.6. If I draw a sample for testing, sealed in the tube, the pH will slowly recover to 8.4 as the disolved buffer does it's job. A great deal of the buffer capacity of the oceans are the coral in them.

But yes, I agree, CO2 is not what's going to destroy our oceans. We've been doing far, far worse things to them for a long time now.

Re:Worse?

[zidium]

0.77 mm/yr * 42 yr/period = 32.34 mm/period; that's 1.25 inches per quarter century or 3 inches per century.

Re:Worse?

[flatass]

That's no satellite....

Re:Worse?

[TheSeventh]

Coastline erosion or deposition is not as dangerous as sea levels rising and flooding everywhere. Erosion is a problem for the coasts, and for the short-sighted who built property on sandy beaches, but sea levels rising affects everyone on the planet. So while somebody living 100 miles from the ocean isn't worried about coastal erosion washing his house away, he does need to worry about the rivers and lakes around him rising and submerging his house permanently. And while it was 1.8mm/year for the last half of last century, it's warmer now than it was then, which means the ice will be melting faster, which means the sea level will rise faster.

Whether the coastline is eroded away or submerged, it's still gone, and that much more water will have other drastic effects as well, besides flooding the coastal regions. Warmer oceans and higher sea levels means more moisture in the air, which means more rain, tropical storms, hurricanes, tornadoes, tsunamis, etc. I'm pretty sure a hurricane does far more coastal damage than erosion would in several years.. So yeah, I care more about sea levels rising than the coastal erosion of rich people's homes in California.

The people in Manhattan as well, aren't going to be worrying about erosion as much as they will be worried about their homes a few miles inland being flooded and submerged. As well as everyone else that lives in low lying inland areas around the world.

You mentioned continental drift in your two previous posts, I assume you're done talking about the continents drifting around now? But you bring up Subduction zones, and you clearly have no idea what they are, and couldn't even bother to look at wikipedia for 30 seconds before talking about them.

People in Subduction Zones don't worry about coastal erosion so much because they are more worried about the vast amount of earthquakes and volcanoes around them, which generally occur in subduction zones.

Re:Worse?

[TheSeventh]

If the sea level rises, it affects everyone, not just those living on the coasts. Rising sea levels will affect those living far inland with rising lakes and rivers, flooding and submerging their homes which are nowhere near the coasts. So yeah, I care more about sea levels rising than erosion washing away rich people's homes in California, and the homes of all the people who were short-sighted enough to build on sandy beaches.

I'm sure the people in Manhattan aren't worried about erosion nearly as much as the nearby water rising and flooding/submerging their homes a few miles inland. And while it was 1.8mm/year in the last half of the last century, it is warmer now than it was then, which means the ice will melt faster, which means the water will rise more quickly.

Whether the coastline is eroded or submerged doesn't really matter that much, it is still gone. And with that much more water, and with the warmer temperatures, that means there will be more moisture in the air, which means more rain, tropical storms, hurricanes, tornadoes, tsunamis, etc.

I'm sure a hurricane would do much more damage to the coast than several years of erosion would do.

You brought up continental drifting in your last two posts, I assume you know you were wrong about that having anything to do with sea levels, and are done talking about it now? But you bring up subduction zones, which you clearly have no idea about, and you couldn't be bothered to spend 30 seconds to look at them on wikipedia before trying to talk about them?

I really don't think people in subduction zones are worried about their tectonic plate moving into the ocean, and they are more worried about the earthquakes and volcanoes which are typical of those areas. If the plate they are on is subducting under another one, the coastline is the last thing they should be worried about.

Re:Worse?

[TheSeventh]

This was a duplicate comment, as it looked like the previous one wasn't saved. Thank you slashdot.

Re:Worse?

[RenderSeven]

If you leave one beer unopened out of every 6-pack, leaving the CO2 sequestered, you'll do more to help the earth than any activist. And you'll have plenty of beer in reserve for the Zombie Apocalypse.

Re:Worse?

[BMOC]

CO2 is one of the primary building blocks that coral-algae symbiosis uses to survive and grow. More CO2 dissolved in the water means coral might actually grow faster:

Many corals, as well as other cnidarian groups such as Aiptasia (a sea anemone) form a symbiotic relationship with a class of algae, zooxanthellae, of the genus Symbiodinium. Aiptasia, a familiar pest among coral reef aquarium hobbyists, serves as a valuable model organism in the study of cnidarian-algal symbiosis. Typically, each polyp harbors one species of algae. Via photosynthesis, these provide energy for the coral, and aid in calcification.[14] The algae benefit from a safe place to live and consume the polyp's carbon dioxide and nitrogenous waste.

The ocean is becoming LESS basic on the ph scale. It is (allegedly) moving more towards a neutral chemistry. It is NOT acidic nor is it becoming "more" acidic.

Stop spouting baseless fear.

Re:Worse?

[BMOC]

Did they add the CO2 to the mixture on geologic timescales? If not, they cannot possibly be simulating the earth properly. Biological processes over eons trumps this simple experiment every time.

Sure, if you throw enough CO2 into the experiment in hours or days, you'll kill coral. However there's no possible way to do this to earths oceans within all of mankind's technology. If instead you're adding fractions of a percent of CO2 to the mix per century (as real life behaves), biology responds to neutralize the increase.

Re:Worse?

[JWSmythe]

    I still haven't figured out how everything on television, even educational channels like History, have become tabloid television. It feels like I can get more reliable information from the Weekly World News, and The Onion.

    You get real news from Comedy Central.

    You get blatant lies and propaganda from Fox News.

    You get sensationalized half truth from every other "news" outlet.

    You get wild ass conspiracies and paranormal BS from Discovery, History, and National Geographic.

    No wonder people seem so dumb. They aren't actually idiots, they've just been exposed to so much "crap as fact" media, that they don't know any better.

    BTW, you're thinking of von DÃniken, not Vonnegut.

Re:Worse?

[gmhowell]

Unopened beer? You tree huggers come up with some insane ideas.

Re:Worse?

[phantomfive]

Coastline erosion or deposition is not as dangerous as sea levels rising and flooding everywhere.

I think you're basically buying into someone's hype or propaganda. You need to take a step back and re-think through this issue with a clear mind. It will do you good.

Re:Worse?

[riverat1]

Lake Mead was essentially full in 2000. Since then a series of drought years has dropped the water level by around 100 feet. 2011 was an exceptional water year in the Colorado drainage so the lake came up some but for 2012 the inflow is expected to be less than 30% of the average from 1981 to 2010. The Lake Mead Water Data web site has historical information about the water conditions in Lake Mead. In particular you might want to look at the Averages by Year data. Also, you can get a summary of the current conditions for the Upper Colorado basin that is updated monthly here.

Re:Worse?

[reason]

This is a complete misunderstanding of the chemistry involved.

Increased dissolved CO2 concentrations (pCO2) make it much HARDER, not easier for corals and shellfish to fix calcium carbonate.

The reaction is:
Ca2+ + 2HCO3- CaCo3 + H2O + CO2
This reaction can go in either direction. It needs to run from left to right to create coral and shells. Increase the concentration of CO2 in the water and you increase the pressure in the other direction (right to left, i.e. dissolution of CaCO3 rather than accretion).

Re:Worse?

[Stuarticus]

What is it that Calcium Carbonate dissolves in again? Maybe this GCSE science site will help your understanding. http://www.gcsescience.com/f3.htm

Re:Worse?

[Stuarticus]

More useful than a cubic metre?

Re:Worse?

[rthille]

We're seeing the results of the 'geologic timescales' experiment we're doing in the oceans now. Corals are bleaching and being dissolved back into the oceans.

Re:Worse?

[phantomfive]

Right, someone else's propaganda, of course.

Well I certainly don't think you would come up with that propaganda on your own! Though it would entertain me if you did.

It fascinates me that you think continental drift is not relevant in an article about sea rise. You are right, of course, continental drift is a relatively small issue compared to tsunamis....the point is, the ocean level rise is a relatively small issue compared to the you land being lost in a subduction zone. And it's a non-issue if your land is growing.

This sentence is also interesting: "But no thanks, I don't want to watch Fox News." Do you think that everyone who disagrees with you watches Fox News? I think that shows some kind of bias.

Re:Worse?

[rthille]

5.6 seems to be the correct pH for rain water.
http://www.epa.gov/acidrain/education/site_students/phscale.html

Re:Worse?

[Firethorn]

It is when all your maps are marked up in acres.

One thing I've noticed about metric vs imperial is that metric is more useful for scientific measures and simplicity. Imperial is more useful for actually doing things without a calculator when 'close enough' is good enough.

Once you're used to the system, doubling, halving, or even tripling or thirding a recipie is easy with imperial. It's a bit more of a pain to do it with metric. When building a house, I've seen people use the base 12 system to do all sorts of useful ratio stuff quickly and easily.

There's nothing all that special about base-10. One can argue that base-12 is more useful in a lot of ways.

Re:Worse?

[RockDoctor]

The sea rose 7" over the 20th century, with zero acceleration in rate until the satellites came online

ITYM "in OBSERVED rate," the satellites being able to gather more uniform and more accurate data, with less variation in biases compared to ground-based surveying.

and no one noticed for 90 years

No-one made much of a fuss about it, many of the areas with patent sea-level change or fall having well-understood reasons for those changes. For example, the Baltic Sea has been shoaling for all of the areas recorded history, but this has been understood since the 1850s (courtesy of M. Agassiz) as the result of isostatic rebound following deglaciation. Similarly, over the same period the UK has been well-known to be tilting along an axis (approximately the Tees-Exe line) due to deglaciation of the Scottish highlands and longer term (Alpine) subsidence in the Thames/ Rhine/ Southern North Sea Basin, which has been happening for 30+ million years.

None of this has excited particularly much comment (well, Londoners bleat about being drowned while Cloggies get on with building dykes) over the 40+ years that I've been aware of the issue. What has changed in that time is that regional surveying has got better and more consistent, allowing global inventories of the changes ... and the realisation that there is a global eustatic change going on, not just local isostatic changes.

Re:Worse?

[Anguirel]

You still can't see how a coastline growing or shrinking might be related to the topic of oceans rising? Or how it might be more important to a person actually living on the coast?

You have trouble seeing how someone's coastline disappearing at half a meter per year is more worrisome than a 3mm ocean level rise? Or how someone living in a subduction zone might be worried about their tectonic plate moving into the ocean at a rate of 50mm per year, more than they are about the 3mm ocean level rise? What is wrong with you?

50mm horizontal is very different from 3mm vertical. There are regions where "dry" land several miles from the normal high-tide point is still only a few inches above sea level at high tide. 3mm up can mean hundreds of meters in.

Additionally, tidal effects are felt hundreds of miles up-river. For example, I know the Hudson River feels tidal effects all the way to Albany, 140 miles up river. Here... http://en.wikipedia.org/wiki/Head_of_tide

So yes, a 3mm vertical rise in ocean level might matter to a lot more people than 50mm of coastal erosion, since it can have an impact along several hundred of miles of rivers and streams that aren't usually considered "coastal", and which are not having any erosion issues at all.

Re:Worse?

[phantomfive]

The point is, 3mm a year is a small amount, and isn't a huge issue.

Really?

[Dmritard96]

"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?

[Drethon]

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?

[saveferrousoxide]

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?

[Jeng]

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

Re:Really?

[Qzukk]

(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?

[TapeCutter]

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?

[tmosley]

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

Re:Really?

[progician]

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?

[tompaulco]

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...)
Surface area is the largest single factor in evaporation.

Re:Really?

[tompaulco]

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)
Ah, well you see, it is humans fault that less water finds its way to the oceans AND it is humans fault that more, um...water, uh... finds its way to the oceans.

Re:Really?

[seandiggity]

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?

It's only contradictory because you've forgotten about aquifers/wells, and seem to underestimate the amount of groundwater the modern industrial world relies upon. TFA specifically mentions groundwater.

Re:Really?

[cpu6502]

I suspect humans are pulling water out of the ground that would normally remain underground. That's causing a slow but measurable transfer of H2O into the ocean and higher levels.

As for "disappearing rivers" that's only true in the western desert areas. In the central and east part of the U.S. the rivers have greater flows than before and often set high tide records. This is a result of humans sucking water out of the ground & then dumping it into the rivers.

Re:Really?

[Mindcontrolled]

Oh that I live to see this day, I agree with tmosley. Well played. That's basically the process, as far as I know - we extract loads of ground water - fresh one as well as fossil one. So sinks for water, particularly deep aquifers, play a lesser role in the water cycle. Since we force water to stay near the surface, evaporation increases and transport to the sea becomes increasingly important compared to transport into ground water. How, in the long term, ocean evaporation rates may change to counteract this is another problem, one for which I do not know any studies out of hand.

Re:Really?

[JWSmythe]

    I would have been happier if he sounded more like Ross Perot. His statement was far too intelligent and topical, compared to most of the candidates.

Re:Really?

[Drethon]

So can you pee into the air and let it evaporate before it hits the ground rather than wasting water to flush toilets?

...sorry for some reason your post made that image pop into my head...

Re:Really?

[tompaulco]

Yes, but the effective surface area of a whitewater river is a lot bigger than the area of land it covers.
Yes, and the effective surface area is increased tremendously by aeration in a white water situation. I would say that it still wouldn't compare to the surface area of a lake formed by damming up that river for years.

Re:Really?

[camperdave]

Is the surface area of the lake behind the dam greater than the area of the now dry flood plain regions next to the river downstream of the dam? Just because there is a man-made lake there doesn't mean that the surface area of the entire river system has gone up. Typically, dams are put in where there are deep gorges, so the surface area wouldn't change all that much anyway.

Re:Really?

[rickb928]

Depends on your location and context...

Re:Really?

[CrimsonAvenger]

Dams actually meter the water out at a specific rate, but that rate is typically less than what would flow naturally.

Absent significant evaporation, releasing water at a rate lower than it would flow naturally will cause the level of the reservoir to increase constantly.

Since this is not the case, I have to assume that either (a) evaporation is a huge factor, or (b) you're wrong....

Re:Really?

[Drethon]

And this is when I wish I could mod funny someone who responds to my comments :)

Re:Really?

[rickb928]

Just let it go. I no longer get mod points no matter my karma or mod ups. Never.

Re:Really?

[saveferrousoxide]

It's the difference between a constant flow and the natural cycle of high and low flow down the river depending on rain or drought. As I mentioned, there are spill-over mechanisms if the level of the lake behind gets too high. There are also planned, controlled releases for that allow for maintenance like dredging the lake bed and unclogging the "drain," so to speak. http://www.ussdams.org/howdam.html

Re:Really?

[tmosley]

This is a good study, and it gives me some real numbers to work with, and an alternative to the human production of water from combustion as a significant contributing factor to global warming. If humans are raising the ocean levels beyond simple thermal swelling, we have enough data to calculate the change in equilibrium between water vapor and water. I had never thought of fossil water as a major source of water vapor, but it makes perfect sense, and explains why areas far from manufacturing, city pavements, and heavy traffic are warming, while remaining consistent with the observation of a lack of warming in the highlands of Asia.

Note that ocean evaporations rates are unlikely to change as a result of this, since evaporation is a function of surface area. Even it AGW were caused by CO2, and the weather was getting warmer, the oceans would evaporate at approximately the same rate (controlled for temperature) as they would if they were a few millimeters deeper as a result of fossil water use. That is, the only real impact of fossil water use is during its use. It won't lead to any more than a short increase in precipitation as the vapor/runoff makes its way to the sea.

Re:Really?

[riverat1]

... 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).

While that's true for the Colorado River I don't think it's true for "most" of the worlds rivers. Practically none of the water withdrawn from rivers and lakes gets destroyed or even removed from the water cycle for any length of time so one way or another it makes its way back to the oceans eventually. What is being added and thus is causing the SLR talked about in the article is mostly the water withdrawn from underground aquifers without being replaced. Like petroleum we will run out of that "fossil" water sooner or later.

Re:Really?

[phantomfive]

Hehe, I hope you're as quick to look for problems in studies you agree with, as you are in studies like this. That is the mark of a good scientist, looking for problems in things he already believes to be true.

sea levels rising for thousands of years

[rubycodez]

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

[WillAdams]

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

[Penguinisto]

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

[mcgrew]

RTFS, less than half of the rise is from us. If we didn't dig another well and never used groundwater to irrigate, the oceans would still be rising, just a little less than half as fast.

Two millimeters per year is tiny, IIRC the moon is moving away from the eath at a higher rate. This is such a slow rise that we will have little trouble adapting.

Re:sea levels rising for thousands of years

[rthille]

You don't have to pump the water up hill to replenish the ground water. Here's a google maps link: http://g.co/maps/8nehd to an impound area on the Santa Clara River in Southern California. They have a diversion dam on the river which allows the water to flow to the side and into the pond(s) when there's enough flow, and otherwise flow down river.

Re:sea levels rising for thousands of years

[Mindcontrolled]

As long as the rate stays constant. Given the current sea ice data, I do have my doubts about that, though.

Re:sea levels rising for thousands of years

[Kaenneth]

Humans are bound to the coastlines however; and not just because of enocomic reasons like shipping.

Why are waterfront homes more expensive? why do people go to the beach and enjoy swimming? It's ingrained in our DNA to live next to bodies of water.

http://en.wikipedia.org/wiki/Aquatic_ape_hypothesis

Re:sea levels rising for thousands of years

[Myopic]

Mmm hmm. Yeah, it's not the rise, it's the rate. Same for temperatures.

Re:sea levels rising for thousands of years

[rubycodez]

there are graphs online of the rate and rise for the last ten thousand years. it's never been constant

Re:sea levels rising for thousands of years

[rubycodez]

that's completely irrational, most people on coastlines won't care fuck-all if the ocean rises four inches in the next 100 years. It doesn't matter for most.

Preventing water from returning to the sea

[Compaqt]

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

[kenh]

My well water is used in my house and is disposed of in my septic system, which returns the water to my local water table - I'd be hard-pressed to figure out how my water usage was somehow contributing to the cataclysmic (if infinitisimal) receeding shore lines around the world...

Re:Preventing water from returning to the sea

[stupid_pygmy]

Most of the water usage is not generated from household use, but from agriculture. As a result, the food you eat has much more to do with water usage than anything else (a good reason to be vegetarian): http://www.un.org/News/briefings/docs/2008/080514_Water.doc.htm

Re:Preventing water from returning to the sea

[justthinkit]

You may delay it, but the water will return to the sea. No matter what clever little trick we try
.

How about filling a lake that has no outlet?

Re:Preventing water from returning to the sea

[rickb928]

There's always an outlet. It will overflow somewhere.

Dam Baby, Dam!

[PrescriptionWarning]

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

Re:Dam Baby, Dam!

[dkleinsc]

... time to put those beavers to work!

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

Re:Dam Baby, Dam!

[TapeCutter]

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!

[Intrepid imaginaut]

You see beaver means vagina in the USA, so he's clearly got some angle about using vaginas to build dams. Not quite sure how that would work, one would imagine the general grappling and lifting would be better done by hand or even by large machines, unless you're talking about Thai professionals of course, man some of them can put a ping pong ball into orbit. One night in Bangkok makes a hard man humble, indeed. ... wait what was I saying?

Re:Dam Baby, Dam!

[nedlohs]

"nuclear fusion" - I think you missed that part.

Re:Dam Baby, Dam!

[rthille]

No, he said Fusion, which would make one Helium atom out of 4(?)Hydrogen atoms. (I assume 4, since the atomic weight of He is ~4x that of H.

Re:Makes you think doesn't it.

[santax]

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%.

That's why geologists now call this epoch

[fredrated]

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

Re:That's why geologists now call this epoch

[fredrated]

Can someone smarter than me explain why my factual statement was modded down to zero?

From wikipedia: "Many scientists are now using the term and the Geological Society of America titled its 2011 annual meeting: Archean to Anthropocene: The past is the key to the future."

I don't buy it

[Waffle Iron]

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

[pr0nbot]

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

[Dishevel]

You actually know that teacher in NC?

Re:I don't buy it

[Mindcontrolled]

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

Let me introduce you to Chernozem - one of the most fertile soils of the earth.

Re:I don't buy it

[hedge49]

Well, well.

Re:I don't buy it

[TheSeventh]

As opposed to you, a clear coward, who, while trying to insult others and call them dumb, can't quite handle the complexities of elementary school grammar. . .

Now, are you trying to say that my 1st grade teacher told me to be self-righteous, told me I'm smart (I could read pretty well in 1st grade), or told me that global warming is real?

Idiot.

Unsustainable.

[Hatta]

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

Re:Unsustainable.

[Jeng]

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

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

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

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.

[hherb]

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.

[dkleinsc]

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.

[dkleinsc]

Well, obviously, trickle-down economics would work.

Re:Unsustainable.

[Jeng]

Was going off of the fossil water article that used the Ogallala aquifer as an example.

Re:Dam!

[houstonbofh]

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!

[lxs]

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

The relevant part

[Corson]

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

[spectrokid]

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

[skine]

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.

Re:The relevant part

[wes33]

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

Re:The relevant part

[TapeCutter]

Old fashioned tidal gauges are very acurate if kept well maintained, a simple tube effectively removes the waves, larger ones use what is called a "stilling well" but the principle is the same as measureing the 'true' hieght of choppy bath water with a perspex tube. Having said that I'm pretty sure the 0.77mm/yr is a statistic, ie: the gradient of the trend over a number of decades or centuries in some areas. An (unexplained) three inch rise over 100yrs is certainly something that could be observed in historical records.

I don't know if these guys are right or wrong, so I cheated a bit by skimming TFA, the source is credible and previous research backs the general conclusion. I still don't know if they are right but either way it is nice to see a slashdot article that highlights a genuine conundrum in Earth science.

Re:The relevant part

[CubicleView]

if...pfff...every year is a hole year on /.

Re:The relevant part

[SteveFoerster]

Two, with a dick year in front of them.

Re:The relevant part

[justthinkit]

How much bigger does the surface area of the ocean get, per mm of sea level rise? (as a percent ifyouhaveit).

Re:The relevant part

[skine]

I don't know if there's any practical way to determine that.

First, such a function would definitely not be linear, given the variety of coastlines. Places that have flat sandy beaches would see a greater increase in local surface area, while places with coastal cliffs would see a negligible increase.

Second, it's entirely possible that an increase in the sea level of 10 meters could increase the surface area of the ocean by a tenth of a percent (350,000 square kilometers, or approximately the area of Germany or Montana), but possibly a far smaller percentage. However, it is estimated that about a tenth of the world's population lives under 10 meters elevation.

I fully admit that this is largely guesswork. Most is based on eye-balling maps such as this:

http://merkel.zoneo.net/Topo/Applet/appletTopo.php?lang=en&file=mondeB

And the estimate of populations in low elevation coastal zones comes from here:

http://www.npr.org/templates/story/story.php?storyId=9162438

Re:The relevant part

[Bigby]

None of that takes into account the transformation of the earth's surface under the water. How are they measuring that and its impact on the water level? I would assume that they take the moving of plates into account.

It could be...

[Troyusrex]

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...

[Dynedain]

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...

[Troyusrex]

You are right! I exchanged miles and meters! So I was only off by a few orders of magnitude....

Re:It could be...

[eastlight_jim]

It is off a bit ;-) ((335,258,000 sq km * 0.77mm) * 1000 kg per metre cubed) / 200000 tonnes = about 1.2 million suezmax tankers.

Re:It could be...

[rich_hudds]

I get surface area of oceans is 3.5x10 ^ 14 m2 so a .77mm increase would be 2.31x10 ^ 11 m3

in gallons I make that 8.75 x 10 ^ 8

If a supertanker holds 8.4 x 10^7 gallons then that makes 10 supertankers which still sounds surprisingly low to me.

Where did I go wrong?

Re:It could be...

[Stickybombs]

Well you have 10^11 cubic meters. And there are a lot of gallons in a cubic meter, so you shouldn't end up with 10^8 gallons. I don't feel like doing the math, but that part is wrong for sure.

Re:It could be...

[rich_hudds]

Doh, got the gallon conversion the wrong way round which puts me out be 10^6.

That sounds a lot more reasonable

Re:Makes you think doesn't it.

[Chrisq]

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:Dam!

[Chrisq]

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.

Human water [mis]use?

[Polizei]

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.

Re:Makes you think doesn't it.

[rickb928]

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:Dam!

[Dcnjoe60]

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.

Confused

[IndigoDarkwolf]

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.

Hoover dam

[spectrokid]

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

Re:Hoover dam

[blueg3]

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

[Half-pint HAL]

The Hoover dam doesn't hold back the world's largest reservoir -- according to Wikipedia, it's number 30. It's a good example for Americans, though. The top 29 reservoirs on the page total 2195.722 cubic kilometers, or another 58.9 Hoovers' worth of water. By blueg3's reckoning (350 cubic kilometers = 1 mm), that's another 6 millimeters. That's only 29 megadams -- there's a few other megadams to account for, and a lot of normal dams. Iceland impounds a huge amount of water in dams. Europe still has a considerable network of canals, and as well as the water in the canals themselves, there's a lot of reservoirs holding reserve water to account for losses at locking. There's also the artificial ponds and cisterns maintained by individual farmers.

All little bits and pieces add up.

And this is only one variable in a very complicated equation that gives us the entire picture of the current state of the world. Each tiny variable deserves to be studied, not to be dismissed.

Anyone else confused?

[Anubis IV]

...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."

Re:Anyone else confused?

[Dan East]

They certainly increase evaporation, and probably absorption of water back into the ground. Whether or not that amount of water is negligible or not is the question. Simply put, less water makes it to the ocean after a river is dammed than before.

Re:Anyone else confused?

[FrootLoops]

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.

Not "any amount"; it's a question of magnitudes. Suppose for the moment that half the world's water will be put behind dams in the next year--sea levels would plummet. The question is, how much water have we taken out of the ocean and squirreled away in dams over the last 50 years? I don't know. Maybe it's significant compared to the amount of water associated with sea level rise, maybe it's not.

Of course, after a river has been dammed and the dam has been filled, the amount of water flowing through should be on average the same as before the dam (modulo the extra surface area of the new lake and possible seepage, etc.). Dams create lakes and regulate water flow, evening out droughts and floods. But that's not the point here.

Re:Anyone else confused?

[Half-pint HAL]

The non-moving water behind a dam is behind a dam. The non-moving water not behind a dam is somewhere else -- and mostly the sea.

More news for AGW alarmists

[bhlowe]

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..

Re:More news for AGW alarmists

[FTWinston]

1 mm over many decades doesn't mean squat..

You missed out the rather important per year part from that sentence.

Re:More news for AGW alarmists

[phantomfive]

If this were a real concern, beachfront property prices would be falling.

Probably not, remember the beach DOES break off even now, houses fall into the ocean, like this, and people are still lining up to build another house on the edge of the cliff when it happens. Beaches are dangerous for more reasons than just sea-level rise.

Re:More news for AGW alarmists

[bhlowe]

I definitely qualify as a computer nerd.. and I also work on alternative energy science (LENR) as a hobby.. I think SlashDot has drunk the Al Gore kool-ade and most of this AGW stuff is poor conjecture and scare tactics designed to extract more taxes and funnel more taxpayer dollars towards solutions that will not solve the dire warnings predicted.

The US has spent $80B since 2008 on climate science.. And besides employing a bunch of people and making a few people wealthy, the net result is of no tangible benefit to mankind. A vibrant free market economy requires that the majority of the people produce a real service or product.

Well, obviously

[Tifer]

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

Re:Dams

[Jeng]

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.

Re:Dam!

[rickb928]

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.

extraction of groundwater

[swell]

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

[Dcnjoe60]

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.

Re:Could be other causes, too

[chrismcb]

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.

How do the lakes rise AND more water runs out of them?
Also... there aren't many Great Lakes in the US. Or do only half of the lakes rise?

Re:Could be other causes, too

[Dcnjoe60]

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.

How do the lakes rise AND more water runs out of them?

Also... there aren't many Great Lakes in the US. Or do only half of the lakes rise?

The bedrock in the area is rising, basically the floor of the Great Lakes. As it rises, the water is pushed out because the volume of space for the water to occupy is less. Accepted theory is the area was compressed during the last iceage from the weight of the ice sheet and has been gradually re-expanding to its natural contour. Of course this does not happen equally at every location and one end of the Lakes is rising faster than the other which has same effect as taking a baking dish full of water and lifting one end. The water runs out the lower end.

Re:Could be other causes, too

[Stuarticus]

Venice is built on a swamp, and as a wise man once said: http://www.youtube.com/watch?v=aNaXdLWt17A

Re:Makes you think doesn't it.

[Dishevel]

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

Just so we are clear here,

[rickb928]

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

Bad humans! Be gone!

Riiiiiight...

Stop peeing in the ocean!

[Snaller]

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

Re:Dam!

[fprintf]

Bedrock is fairly impermeable.

How?

[Just Some Guy]

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?

[Sir Realist]

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.

Re:How?

[swillden]

"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."

But they don't. When you build a new one, then for a few years afterwards they may reduce the flow to the seas, but only as long as the reservoir level is rising. Eventually, they get full, and inflow equals outflow, or we draw them down, and outflow exceeds inflow.

Re:How?

[Sir Realist]

Well yes and no. There's the water in the reservoirs themselves, that is still missing from the oceans. That doesn't account for a continuing decrease in sea levels though, except for the continuous creation of new reservoirs. But reservoirs also have an enormous evaporation rate, and the water that we take out of them for use often never makes it back to the ocean, for various reasons: we spray it on our gardens and golf courses and it evaporates, is absorbed by plants, or returns direct to groundwater. We flush it down our toilets, and it goes to sewage treatment plants where it sits in enormous pools with high evaporation rates while being treated. In California it gets run in open-topped canals through deserts down the length of the state, evaporating all the way. That sort of thing. The water isn't removed from the ecosystem, but a fair bit of it bypasses the ocean part of the cycle. Even ignoring things like Hoover dam and the Colorado - which makes a bad example because of the huge amount of its water which gets used out of the river's watershed - you generally see much smaller amounts of water flowing out the ocean ends of rivers after they're dammed (for water storage; I'd imagine the effects of flood control dams are smaller, but I couldn't personally vouch for that.)

Having said all of that, its hard to imagine that any of it adds up to a hill of beans when it comes to _ocean_ levels. I'm more-or-less trusting the quoted research on that, not having the time to chase it up myself at the moment.

Re:How?

[Intrepid imaginaut]

And it took this long to mention this woefully obvious point? Slashdot, you have failed.

This whole article has a reek about it, and I like the pong not at all.

Re:How?

[swillden]

I agree that reservoirs -- and many of the uses we make of the water -- increase evaporation, which Just Some Guy mentioned. But that's not what the sentence you quoted says. I also find it hard to believe that reservoirs, even though all of their direct and follow-on effects, add up to anything in the context of ocean levels.

Re:How?

[Sir Realist]

Yeah, like I said; I have trouble with the statement; but until I get a chance to read the research, I'm giving it the benefit of the doubt. I can think of plausible mechanisms that would at least contribute to that effect, so while its difficult to believe that they would be of an appropriate magnitude, I'm not going to dismiss it out of hand.

My only real point was that the /. summary says one thing and the original article says the opposite... and then to show that again for this post, I went back and re-read the summary, discovered I'd misread it the first time, and got embarassed. So there's that.

Re:How?

[FrootLoops]

The summary referred to a 40 year period, during which time I imagine many new reservoirs were created by damming rivers. As the reservoirs filled they would soak up water that otherwise would go back to the ocean. There are other effects to consider (evaporation, seepage, increased human water use because of the dam...), but the summary's statement isn't patently false.

Re:How?

[FrootLoops]

reservoirs don't make this problem worse, as the /. summary implies

You misread a mistake into the summary. It says

It [the observed sea-level rise between 1961 and 2003] would be even worse if we weren't also locking up lots of water from rivers behind dams like the Hoover Dam.

The antecedent of "it" isn't terribly clear, I suppose, and the sentence uses a double negative, so the mistake is understandable.

There is an actual mistake in the summary here, though: the Hoover Dam was made in the 1930's, and I imagine Lake Mead filled during that time. They should have picked a dam whose reservoir filled between 1961 and 2003, like the Atatürk dam which filled between 1990 and 1992.

Re:How?

[Sir Realist]

Wish I could mod you up - yep, I got it wrong.

Re:How?

[swillden]

By an utterly insignificant amount. Do the math, you're talking about raising the ocean levels by micrometers.

Re:How?

[chrismcb]

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.

TFS says

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

And then you showed evidence ""Artificial reservoirs, ... have the opposite effect, locking up water that would otherwise flow into the seas." which seems to be the same thing TFS implies. So how is the summary wrong? I think it is YOU who gets no biscuit.

Re:How?

[chrismcb]

. Eventually, they get full, and inflow equals outflow, or we draw them down, and outflow exceeds inflow.

If only the water went somewhere else than just the ocean...

Re:How?

[nickersonm]

Perhaps you should do the math. Assuming a 3.6e8 km^2 surface area for the ocean, the largest reservoir alone, going by Wikipedia's 180km^3 figure, could account for 0.5mm of sea level. A trivial calculation. Others have posted similar further up the page.

Re:How?

[FrootLoops]

Wish I could mod you up

Hah, ironically your original post got modded up and mine is unmodded. Oh well :)

Re:How?

[swillden]

I stand corrected.

Re:How?

[Sir Realist]

Yep; all my biscuits are belong to OP. I totally misread it.

Re:Since the ice age?

[tomhath]

It's called Post-Glacial Rebound, 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?

[The Mighty Buzzard]

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?

Land Mass Rising

[na1led]

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

sea level rise has been a lie/scam anyway.

[argStyopa]

http://www.telegraph.co.uk/comment/columnists/christopherbooker/5067351/Rise-of-sea-levels-is-the-greatest-lie-ever-told.html

But if there is one scientist who knows more about sea levels than anyone else in the world it is the Swedish geologist and physicist Nils-Axel MÃrner, formerly chairman of the INQUA International Commission on Sea Level Change. And the uncompromising verdict of Dr MÃrner, who for 35 years has been using every known scientific method to study sea levels all over the globe, is that all this talk about the sea rising is nothing but a colossal scare story.
Despite fluctuations down as well as up, "the sea is not rising," he says. "It hasn't risen in 50 years." If there is any rise this century it will "not be more than 10cm (four inches), with an uncertainty of plus or minus 10cm". And quite apart from examining the hard evidence, he says, the elementary laws of physics (latent heat needed to melt ice) tell us that the apocalypse conjured up by
Al Gore and Co could not possibly come about. ...
When running the International Commission on Sea Level Change, he launched a special project on the Maldives, whose leaders have for 20 years been calling for vast sums of international aid to stave off disaster. Six times he and his expert team visited the islands, to confirm that the sea has not risen for half a century. Before announcing his findings, he offered to show the inhabitants a film explaining why they had nothing to worry about. The government refused to let it be shown.

But hey, we all know that "there is 100% consensus among the serious scientists on AGW", right?

Re:sea level rise has been a lie/scam anyway.

[Overzeetop]

"Despite fluctuations down as well as up, "the sea is not rising," he says. "It hasn't risen in 50 years." If there is any rise this century it will "not be more than 10cm (four inches), with an uncertainty of plus or minus 10cm".

So...he's basically saying that he has a mean rise somewhere just shy of 10cm, and an uncertainty of 10cm. That would, to a simple engineer like myself, suggest that sea levels ARE rising, and that they are rising at a rate which is somewhere between a negligible amount and 20cm over 100 years, or (wait for it) 2mm per year. TFS suggests that 1.8mm/yr is the annual average amount for the last fifty years. Presuming that there was no change - or a negligible one - from 1910-1960, that would average out to 0.9mm.yr.

That's 9cm in 100 years or 10% less than Dr MÃrner's "not more than" mean, and well within his +/- 10cm. band.

Re:sea level rise has been a lie/scam anyway.

[kenboldt]

now now, let's not let facts get in the way of a good story.

Re:sea level rise has been a lie/scam anyway.

[ath1901]

Mörner is not one of the serious scientists. I thought I recognized his name and looked him up at wikipedia. One of his previous achievements is winning the "Deceiver of the year" award for supporting dowsing.

http://en.wikipedia.org/wiki/Nils-Axel_M%C3%B6rner#Views_on_dowsing

Oh, and his claims about the sea level is not supported by satellite measurements.

Re:sea level rise has been a lie/scam anyway.

[CrimsonAvenger]

So...he's basically saying that he has a mean rise somewhere just shy of 10cm, and an uncertainty of 10cm.

Actually, it looks like he's saying the mean rise would be ZERO, with an uncertainty of 10 cm.

Plus or minus 10, but not more than 10....

Re:sea level rise has been a lie/scam anyway.

[CAIMLAS]

And, correct me if I'm wrong, but "no more than 10cm, with an uncertainty of 10cm" means to me that the answer he came to is statistically insignificant, or something like that. He's trying to lie with science.

Look, either you can measure it, or you can't. You can't say "it's risen 10cm" when you could be off by as much as 10cm. Science doesn't work that way. "There may, or may not be a room with a door down the hall to your left". Sorry. Try again.

This whole thing reads like "we can stop global tide levels from rising any further by not using the toilet". It's retarded. Do people even realize where ground water comes from?

Inherently stable system

[PPH]

But sea level rise due to global temperature should be offset by the associated decrease in the number of pirates. As this number declines, the associated hull displacement contributing to sea level rise decreases, bringing the system back towards stability.

It never fails to amaze me how little we understand the systems that we are attempting to regulate. Possibly with serious unforeseen consequences.

Now you kids stay off my lawn! I'm doing my part to reduce sea level by watering it.

Sub sea profile changes?

[atouk]

With all the earthquakes that happen undersea every year, the is some major ocean fllor remodeling going on. Of course the zero sum model that they are pushing also must mean that the ocean volume change because of tectonic shift is also zero sum.

A few thousand square mles of ocean floor raising a couple inches will have more of effect to sea level increases than all man made activity over the last ten thousand years.

I'm suprised that they haven't blamed hunting beavers in the 1700's for an increase in sea level changes because all the beaver dams that would have been built would have prevented ONE TRILLION (pinky to upper lip) gallons of water from entering the sea.

Re:Sub sea profile changes?

[trenobus]

Exactly. Changes in the volume of the ocean basin have a huge potential to change sea level. The sea level could drop even if the volume of water increased. But I don't believe that's the end of the story. I think the weight distribution of water on the tectonic plates can affect tectonic activity. The melting of polar ice caps could cause large changes in the weight distribution, and I expect that will increase tectonic activity until a new equilibrium is established. So more earthquakes and more volcanic activity. And more volcanic activity could reduce sunlight to the surface, which could cause more ice to form, changing the weight distribution again.

It's not a simple system. I think our understanding of how it all works is still in its infancy.

1 great lake is falling not rising

[bussdriver]

Actually, I know that 1 of the great lakes (forget the one) is lower and the amount is approximately the amount taken out of it for freshwater use (farming is always a big water user.) I heard about the studies back when the Great Lake states were discussing a deal where they would forbid any other state from stealing water from the Lakes - which sounded a bit nuts to people up here but people in AZ just assume someday they'll get water from the Great Lakes like we were just next door. I followed the hardly covered issue back then because having been in AZ, I know it was not crazy to the people wanting to make the deal. Thankfully our politicians opposed it (no lobby or media coverage) but when the time comes they'll easily change positions and undo past law if properly bribed.

Re:1 great lake is falling not rising

[Dcnjoe60]

Actually, I know that 1 of the great lakes (forget the one) is lower and the amount is approximately the amount taken out of it for freshwater use (farming is always a big water user.) I heard about the studies back when the Great Lake states were discussing a deal where they would forbid any other state from stealing water from the Lakes - which sounded a bit nuts to people up here but people in AZ just assume someday they'll get water from the Great Lakes like we were just next door. I followed the hardly covered issue back then because having been in AZ, I know it was not crazy to the people wanting to make the deal. Thankfully our politicians opposed it (no lobby or media coverage) but when the time comes they'll easily change positions and undo past law if properly bribed.

Actually, the whole region around the Great Lakes is rising. It was compressed during the last iceage and has be returning to it's normal, decompressed state ever since. If it was simply water being taken out of the lakes for other use, then the level would be low everywhere. However, the one end has raised significantly (in geological terms) and has nothing to do with water usage. However, the water that was in the now lifted area has run out, ultimately into the ocean (through the normal channels).

Other parts of Canada and the northern Midwest are also experiencing the lifting/tilting. They just don't have massive bodies of fresh water on top of them so it isn't noticeable like it is on a shoreline.

Re:1 great lake is falling not rising

[Bigby]

The point wasn't about water use from the Great Lakes, but that the Lakes are physically rising...like a mountain would. If the bottom of the lake rises faster than the mouth than it will drain at a higher rate.

If Only...

[kenh]

If only there were some way for water in the oceans to be reclaimed - perhaps we could find some way to take water from the oceans, form them into big "clouds" and then have some sort of propuslion system (wind currents?) push them over dry patches of land and somehow have that water somehow drop from the sky onto the ground...

Oh wait, this might take care of it.

Re:If Only...

[ongelovigehond]

If rain were the answer, why do you think people are pumping up ground water in the first place ?

Re:Makes you think doesn't it.

[Sulphur]

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.

In which case the oceans have less volume.

Anthropogenic Global Draining

[J'raxis]

I can't wait to see how they work Anthropogenic Global Draining into the overall eschatology...

Re:Anthropogenic Global Draining

[tomhath]

Shallow aquifers won't make much difference, because if the water isn't pumped out of wells it eventually runs out of surface springs anyway. Many major US cities like New York, Detroit, Chicago, etc. use surface (lake or reservoir) water anyway. There are a few deep aquifers in arid regions that apparently hold water captured during earlier climate cycles like the Ogallala Aquifer. The article doesn't convince me that this is a significant contributor to ocean levels rising, it seems to base too much on unproven speculation.

Re:Anthropogenic Global Draining

[Mindcontrolled]

If you had any clue, you'd know that influences on the water cycle are long since part of climate models. But you are not interested to have a clue, are you, you have an opinion instead.

dihydrogen monoxide

[CoderFool]

I have been reading up on dihydrogen monoxide (water) and it's dangers (dhmo.org) and, after reading this article, I say DHMO is not worth the trouble and we should just ban it.

Very funny, but aquifer depletion...

[Radical Moderate]

is a real problem. Sure, eventually those aquifers will fill up again, but we'll be dead before that happens, and in the meantime how do we irrigate the crops that depend on wells for water?

Personal Water Use -

[hedge49]

Water use anywhere is sustainable within the recharge and filtration parameters of the aquifer/surface supply. And the cost to bring the water to US drinking water standards. Trouble has been that water rights laws are traditionally written in scientific ignorance, and politics will trump science for the time being, usually to the detriment of real individuals in favor of the most recent sub-category. If you want an entertaining read on the subject, try 'Centennial' by Jamess A. Michener. Skip the dinosaurs, and the murder mystery, and go to the aquifer part. But global warming has consequences for water beyond sea level rise. Now that the Great Lakes don't freeze over each winter, evaporation continues all year. Malaria is coming back to the Ukraine now that the swamps don't freeze and kill of the mosquito population. The Brits are making wine. No worries there, though, cause none will make it offshore, both as a consequence of local demand and external standards. The overwhelming preponderance of humanities' unsustainable global activities are a result of concentrated waste injection (feed lots, chicken & pig farms, sewerage outfalls, and everyone pees upstream of NO), or water use/diversion (as in the movie Chinatown). The circulation of water is like blood in an animal. It can take a certain level of bleeding, cuts & scrapes, or pathogenic attack, and survive. But what we're doing in both willful ignorance and greed (privatization of water supplies in South America) is accelerating the detriment that global warming represents to inland fresh water supplies, and will sicken and kill the beast. Hell, women have anti-freeze and flame retardent in their breast milk because our water filtration / treatment systems aren't meant to keep that stuff out. So, look for water wars next, and for your water bill to start looking like your cellphone charges, and for businesses to crop up to make water re-use (toilets) more common. The earth makes a great natural filter, unless poisoned with heavy metals. Or mining runoff. Look to the coal industry for a huge contribution to lowering water quality, both as a function of runoff, and of drastic geological changes that cap or divert natural surface flows. Look for the poisoning of entire ecosystems by fracking. They (Warren Buffet, et. al.) were smart, and got grandfathered in before the burning tapwater, and surface hydrocarbon venting started. It takes 1 PPM of any petroleum component to make water undrinkable, and it's a bitch to remove the lighter molecules either by filtration, RO, or catalytic settling. So, don't pour your crankcase oil down the storm sewer, recycle it. Don't water your lawn, let it die off in favor of locally hardy species. Stop treating for minor pests, and go organic for gardens, with natural remedies for pests. Jacques Cousteau said that the earth, if scaled to the size of an egg, would be different from a stone only by the addition of a single drop of water, and a speck of dust. Love him, or sick-to-death of his preaching (while using some pretty energy intense equipment) he understood how complicated and complex the water issue is. A few hundred nodes on a Cray would be a good start for local basin study, and something bigger for the global picture. It's as complicated as atmospheric weather, but while interconnected, is much more difficult to quantify. It's mostly underground, and you can't rubber ducky it as easily. And, God Almighty, stop Monsanto and their brethren, who developmpatented GMO corn, etc, so their Roundup will not affect the plant. But it's only creating 'super pests' that drink roundup like koolaid.

7 Billion People

[sixx66]

With an Earth population of 7 Billion, that's an awful lot of shitting, pissing and flushing going on. Add to that what industry uses and it is hardly surprising.

Displacement caused by shoreline erosion

[j-stroy]

umm... any beachgoer knows that the sea tosses up sand, rocks and debris during storm season, and also breaks the big rocks into little ones, pulling the shoreline under the water. Since coastlines are fractal, they can be very long for a certain somewhat small area of water.. also fresh sediments washed downstream from all the river systems. What about the displacements caused by these effects on the seabed, or sea plants and animals fixing atmospheric gasses into their biomass? No doubt these things have been considered.. but have they been considered accurately?

I don't understand

[jweller13]

I'm confused. How does locking up water in LAND reservoirs increase sea levels? No I didn't read the source article.

Clearly...

[roc97007]

...we need more dams.

Re:Wrong Science

[Mindcontrolled]

Well, we are doing a lot more than drinking and pissing, don't we? We irrigate, we pump ground water etc.

Let me try a simple model. It's not a working model, but it shows on a very simple scale how things are interconnected:

Let A,G,O,S be the amount of atmospheric, ground, oceanic and surface water.

Now, we can assume that the rate of change for each is at least partially dependent on its amount. We can thus formulate differential equations.

For example, surface water gets replenished by precipitation and by groundwater seeping out from natural wells. Therefore

dS/dt = k(AS)*A+k(GS)*G

k(AS) and k(GS) being first order rate constants for transfer of atmospheric and ground water to the surface, respectively.

That's not all of course, surface water is also lost to the other reservoirs. So:

dS/dt = k(AS)*A+k(GS)*G+k(SA)*s+k(SG)*S+k(SO)*S

Nomenclature for the other rate constants as above. Now, we can do this for A,G and O the same way and get a system of differential equations, which in reality, are of course not strictly first order and not strictly dependent on the simple amounts, but lots of other factors.

Since we are playing with the rate constants, in particular related to evaporation and ground water extraction, we get measurable changes in A,G,O and S.

Simplified, but voila, Science.

Re:Since the ice age?

[Half-pint HAL]

It's called Post-Glacial Rebound, 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.

Is it only the beds of the Great Lakes that are rising then? Not, like, the entire continent around them...??

Re:Dam!

[Half-pint HAL]

Check the spelling of the GP and GGP posts. Hover dam. Hover. Dam.

Solution

[GameboyRMH]

Coastal reservoirs with hydro-power dams. Place your municipal water intakes here so that the outgoing water supply is reused before it hits the oceans.

Let's alarm everyone of the obvious!

[neurosine]

Water tends to flow. Yes, after being extracted from the earth much of it (hopefully) flows into the ocean (as opposed to outer space.) Although this does account for some water displacement, what is the point or insight we should take from this. Should it distract us from the fact that, much more crucially, the filtration process we have known and enjoyed for so long is being (almost systematically) ruined by interest who gain to profit from selling us clean bottled water and wiping out the 'free' water we have traditionally been able to enjoy as a species? Do you not see this as a simple side effect of this process? Sure we are having an effect on the system and should wise up or be culled, but in all likelyhood there's a mechanism already in place for that which we're simply unaware of. The earth will be fine. You and I and all of our digital ink and aspirations, on the other hand; are temporary. Not to say our bits and pieces aren't eternal, but that their coalescence into you and me and the meanings we assign to those things are. Olden evil always burns itself out in the end, and yeah there's alot of collateral damage if you assume the universe isn't unfolding as it should. My body is 80+ percent water right now. All of it will be gone next week, perhaps en route to the ocean....I actually quite often ensure this by peeing in the ocean. It's fun. But don't blame me.

Re:Dam!

[TheSeventh]

. . . . . whooooooosh! . . . . .

Re:Wrong Science

[riverat1]

Precisely!

Re:To those struggling with the math... LOOK HERE

[riverat1]

No, water vapor is unable to drive air temperature changes since the amount of water vapor in the atmosphere is regulated by the air temperature. You may be able to effect some temporary local changes from adding water vapor but globally it has no effect.

Re:Dam!

[ignavus]

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

It's a Hoover Dam. It vacuums up all the water, so it disappears. A hover dam is more like a cloud in the sky. Well, until it rains.

Re:Your sig

[rthille]

Which two? :-)

Questionable science.

[Andreas Otto]

I'm going to ignore the blatant hysteria and sensationalization of the article and concentrate on one word in this article. "could"... this means in scientific terms "we have no clue why these figures don't add up and are just making shit up".