Is Groundwater Depletion Causing Sea-level Rise?

by |November 10, 2010

A recent study from Yoshihide Wada and other researchers from Utrecht University attempted to assess the status of global groundwater depletion—that is, the amount of water that is being drawn out from underground reservoirs that is not being replaced by precipitation—and came up with some startling conclusions. Chief among them that depletion of groundwater may be contributing to as much as 25 percent of observed sea-level rise in recent years.

Groundwater pumping in India for irrigation.

What does this mean? Try to imagine it this way: human beings have stuck giant straws into the ground all over the world and are sucking out ancient water that has been there for, in some cases, millennia. That water is initially used to irrigate crops, water lawns, etc, but then it has to go somewhere, eventually into the sea. Or to put it another way, as Duke University’s Bill Chameides puts it, “Mankind is moving buckets and buckets of water from land to the ocean.”

To conduct their study the authors extracted country-based data on groundwater use, combined it with estimates of water demand (based on population density and location of irrigated areas) to determine how much groundwater was being withdrawn. They then subtracted that figure from an estimated rate of groundwater recharge.

Patrick J. Michaels, a climate change “skeptic” who writes for the Cato Institute has already seized on the study as supposed evidence that global warming isn’t as bad as we think. Under a part of his blog “The Current Wisdom” subtitled, “More Good News About Sea Level Rise” he writes that the Wada study “estimates that about 25% of the current sea level rise has nothing whatsoever to do with “global warming” from any cause, but instead is contributed by our increasing removal of fossil groundwater to suit our growing water demands.”

But as Chameides points out “the groundwater depletion story of Wada et al doesn’t change the big-picture story of climate change and sea-level rise. Should the Greenland or Antarctic ice sheets go, the contribution to sea level from groundwater depletion will be … well, like a drop in the bucket.”

In fact, according to Chameides, the IPCC suggested that groundwater might be contributing to sea-level rise, but did not quantify how much because of uncertainties. Furthermore, as far as I know no one has studied to the degree to which the human pressure to accelerate groundwater depletion is exacerbated by increasing drought caused by climate change.

One thing is for sure though – for anyone who has studied the issue, there is no “good news” in the depletion of groundwater at such staggering scales. Take India, where the exploitation of groundwater is already taking a massive toll—in the form of lost productivity, huge government costs for subsidies and energy consumption, unstable electrical infrastructure, unsustainable debt burdens, displaced and suicidal farmers, families suffering from fluoride poisoning (a result of ever-deeper drilling of wells) and saltwater intrusion among many other consequences.

As Marc Bierkins, one of the Utrecht University study authors, told,

If you let the population grow by extending the irrigated areas using groundwater that is not being recharged, then you will run into a wall at a certain point in time, and you will have hunger and social unrest to go with it . . . that is something that you can see coming for miles.”

Consequences are not limited to the developing world, though—two of the areas most at risk of groundwater depletion according to the study are the Midwest United States (which sits above Ogallala, a massive fossil aquifer) and California—two ends of the breadbasket of the U.S. and much of the world.

In the end, many of the solutions to groundwater depletion end up sounding a lot like those put forth to mitigate climate change. Conserve both energy and water; adopt more sustainable agricultural practices; grow more trees. The real good news is that we can apply strategies to address both groundwater and climate change simultaneously — if we can find the will to do so.

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14 thoughts on “Is Groundwater Depletion Causing Sea-level Rise?

  1. Jeremy says:

    “The real good news is that we can apply strategies to address both groundwater and climate change simultaneously — if we can find the will to do so.”

    I agree with your point Lakis, but given recent events I’m not optimistic the U.S. can, or will, muster the determination you mention. After the recent midterm elections, Obama admitted the American Clean Energy and Security Act of 2009 (aka the Waxman-Markey cap and trade bill) is likely dead in the water, so to speak. And now it seems the Republican-controlled House will seek to cripple any EPA efforts to enact meaningful environmental policies, perhaps by cutting the Agency’s budget.

    Though conservation is an important part in curbing both climate change and the depletion of natural resources, I fear that as long as our government continues to ignore these issues they will continue to worsen. Perhaps more information and better education will help motivate people, and politicians, somewhere down the road. But as India and China continue to industrialize it seems likely that stakes only stand to get higher in the near future.

  2. The answer is to incentivize the creation of surface freshwater impoundments.

    Check out; Great Sacandaga Lake Deepening Project.

    Or go to our website;

    Everybody’s got to make-a-buck, so everyone else can benefit….

    And this can be done in thousands of places about the globe.

  3. Melissa says:

    The other answer is recycling water. We cannot create more water but we can extend the water’s life cycle. We can do more with what we have. Wastewater, cleaned, and then used for irrigation.

  4. Lakis Polycarpou Lakis Polycarpou says:

    Thanks for your comments.

    Jeremy: I share your frustration over the political climate. The only thing I can say about that is that we just have to keep up the political pressure and work on problems in other ways. Not much of an answer though.

    Arthur: Your project sounds interesting — I will have to learn more about it. Has it been tried elsewhere? I am curious about reproducibility, infrastructure costs, etc. as well as environmental consequences.

    Melissa: I totally concur — making use of wastewater through innovative treatment process — especially biological treatment as John Todd (and your company) promote — seems like a no-brainer. I wonder how much water could really be saved if such approaches could be scaled up? And how much would broad-scale implementation cost? And, given that the idea has been around for several decades now, why is it not more broadly adopted?

    Again, the limiting factor seems to be on the policy front — as long as people pay virtually nothing to exploit groundwater, it may be hard to get broad scale implementation of things like sane waste water treatment.

  5. Ananta Boonsopon,M.D. says:

    I think either Global warming or pumping up the undergroundwater causes more rising of Sea-level, the world is now under threat of danger.
    Pumping up undergroundwater does not only increases sea water, but also causes land sink , while Global warming when come to critical point causes melting og Polar Icecaps. Can we imagine what will happed ?

  6. Griffin Crosby Jr says:

    Arthur A. is very correct in surface water retention. Water does not leave this planet. It can be in three forms. But, man can pollute it beyond usage. Water and its usage is not taught in schools anymore (only liberal agendas). I feel the USA had made more strides than any other country in water regulations and protection and not because of the EPA. My saying ‘In a bureaucracy, they create a problem to justify their job. No job means no income, no hopitalization, no retirement all from tax payer expense.’

  7. Lakis Polycarpou Lakis Polycarpou says:


    Thanks for your comment.

    Do you have any evidence that water quality in the United States has improved *in spite of* and not because of the EPA? Can you give any examples?

    I say this as someone who is sympathetic to the idea that regulation can often be irrational, serve vested interests rather than the public, or have negative unintended consequences. (Some examples being that until recently it was illegal to harvest rainwater in Colorado, or the fact that ecologically important graywater recycling systems are all but illegal in much of the country). But I find your assertion about the EPA questionable.

    Also, whatever strides the US has made in terms of quality, in terms of exploitation it doesn’t seem to me that we are doing so well — see my points above about California and Ogallala.


  8. Quote from William E. Marks’ 2001 prescient book, “The Holy Order of Water, Healing Earth’s Waters and Ourselves”:
    “Sea Levels continue to rise for various reasons. First, as mentioned earlier, the worldwide release of water into Earth’s atmosphere by the destruction of trees and other vegetation; the ever-increasing removal of groundwater; the loss of humus in topsoil for storing water; and the rapid evaporation of rainwater from human-made surfaces such as asphalt, concrete, and buildings – is causing the water cycle of the planet to carry more water into the atmosphere at an ever-increasing rate.
    In this book, Mr. Marks further explains how heavy concentration of water behind dams; sediment collection behind dams, and groundwater pumping is causing the collapse of underground soils, gravel and rock formations – thus forever destroying areas of groundwater storage. Mr. Marks further explains that because freshwater is 40 times lighter than saltwater – large areas of Earth’s continents saturated with freshwater “float” on top the heavier salt water intruding beneath the continents from seas and oceans. The removal of freshwater and trapping of water and sediment behind dams is causing our “floating” continents to “sink”.
    According to Mr. Marks, as our heavier continents sink – they push down on the underlying mantle of the Earth’s crust – which in turn causes the crust beneath the oceans to rise and further accelerate and exacerbate rising sea levels.

  9. PS – As far as global warming is concerned – it is recognized by many leading scientists that increasing the quantity of water vapor in Earth’s atmosphere is one of the major contributing causes of global warming. This is due to water’s innate ability to trap and hold heat in the atmosphere – just like it does in our Earth’s oceans.

  10. Dear Lakis:

    So far as I know, after extensive lit reviews, I have not found any examples of sandharvesting mineral of economic importance to pay for freshwater impoundments. I only wish I hadn’t picked on minerals shed from the southeastern Adirondack’s high-grade metamorphic terrains, for my first pilot project. New York State is so dysfunctional. However, after years of persistence, the State is about to join me as a co-applicant to explore down to bedrock, the total ore reserve in the Great Sacandaga Lake. In New York though, that only means we’ll be able to get at that in about a year or so….

  11. rod krug says:

    here is a link to see the Depletion in the High Plains Aquifer…..

  12. Kathy Ylostalo says:

    As a public school science teacher, I believe that we will make much more progress in our fight to save our environment and our groundwater by educating the public, not through public policy. If we don’t change people’s hearts, they will not follow any policy regardless of the money and time spent to design and enforce it. If we spent the money instead on public education programs and impress upon our children and their parents that we could soon be fleeing from ghost towns in search of water and food if we do not better manage our earth’s resources, I believe we may be able to achieve long term effects that would outlast any policy that ebbs and flows depending on government majority.

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