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Climate Hustle

Satellites find over 500 billion tons of land ice melting worldwide every year, headlines focus on Himalayas

Posted on 25 February 2012 by MarkR

The GRACE program is a triumph of our technology – a pair of satellites nicknamed ‘Tom’ and ‘Jerry’ that act like a pair of scales for the Earth below them. They have weighed Australia getting heavier as floodwaters rose, the Earth getting fatter thanks to ice cap melt, and the drying up of Texan water supplies.

Now scientists have produced the first global map of change in the mass of land ice on Earth for 2003-2010 (Jacob et al, 2012), see it in all its glory in Figure 1. Unfortunately the resolution of the GRACE satellites means they can't reliably measure ice areas smaller than 100 km2 (almost 40 square miles), so these are not included in the study.

 

Figure 1 - map of changes in ice thickness estimated by Jacob et al. Blue means losing ice and red means gaining ice. Changes in geology and groundwater have been accounted for (supplementary information). The red spot in Africa is an artifact. The units are 'centimetres of water equivalent per year': the change in water thickness that would be needed to cause the measured mass change.

Biggest ice sheets: melting faster than 2007 UN figures, no surprise there!  

The first things that jump out at you are probably the big blue areas around Greenland and Antarctica. The new results are similar to those already covered at skepticalscience, such as Garder et al, 2011's work on Baffin & Ellesmere islands, plus other measurements of Greenland and Antarctica. It's no longer news that the 2007 UN Intergovernmental Panel on Climate Change (IPCC) computer simulations were far below what has happened.

Greenland and Antarctica have lost almost 400 billion tons of ice every year according to these measurements, twice the loss expected from all the world's other glaciers. This helps to explain why sea levels are rising at the high end of IPCC expectations.

 Figure 2 - tide gauges (red), satellite measurements of sea level (blue) and IPCC computer model expectations (grey area) from Allison et al, 2009.

Worldwide glaciers mostly in retreat - down 1.2 trillion tons in 8 years

For the first time entire mountain ranges of glaciers have been weighed. There are at least 160,000 glaciers worldwide and in the World Glacier Monitoring Service's last update only 136 were weighed. Thousands have been pictured by satellites (e.g. Le Bris et al, 2011, Paul & Svoboda, 2011, Narozhney & Zemtsov, 2011) and found to be mostly shrinking in area, but photos can't measure thickness and therefore total weight.

GRACE shows about 150 billion tons a year of glacier melt which is actually less than some expected. It seems that glaciers in the high mountains of Central Asia (around the Himalayas) only lost about 4±20 bn tons of ice a year. Previous work expected closer to 50 billion tons of loss.

Relative stability in Asia is the surprise, and steals the media spotlight

500 billion tons of ice a year of land ice is being lost, whilst one region is doing about 50 bn tons/yr better than expected. Naturally, the anti-climate science editorial policies of Fox News, the UK Telegraph and Daily Mail ensured headlines focused on the Himalayas result, while some others like Reuters took a more complete view.

At Skeptical Science we think it is important to look at all of the data, which is why this post started with the big view. However, the Asian result is interesting and new so it's definitely worth exploring.

What's going on in Asia?

In 2010, Matsuo & Heki used GRACE to calculate a loss of almost 50 billion tons a year in the same region until 2009, compared with 4 billion in the new study (with a large range of possible values).

The new work includes some extra areas which Matsuo and Heki didn't, so if you do an apples-to-apples comparison then the difference is 47 versus 11 billion tons a year.

It appears that North India has been using more groundwater than expected and this has now been better measured, explaining about 25 bn tons of the difference. The rest might be because of extra heavy snowfalls in 2010, data which wasn't available to Matsuo & Heki.

Figure 3 - Change in mass of glaciers in High Mountain Asia as measured by GRACE. 1 Gt = Gigaton, or billion tons. Matsuo & Heki calculated 50 billion tons/year of ice loss, but they didn't have the 2010 data which saw 400 billion tons of accumulation in one season: more than the total loss they expected over 8 years! This shows that short term trends are not reliable indicators.

GRACE weighs everything and the scientists subtract the effect of changes in the Earth's crust or stored water, which introduces the possibility of error. The new study considers changes in melt lakes, plus underground water storage and erosion and conclude that they don't make a big difference. The effect of rising or sinking rock due to tectonic activity or changes in glaciers is included by the scientists using a computer model - if this is found to make mistakes then the results could change (possibly drastically) in future. This is why other measurements are needed to confirm these results, and why other methods are often considered more reliable than GRACE only measurements.

We can also see that 8 years isn't necessarily enough to make solid conclusions about the long term response of a single area, especially when weather can cause glaciers to grow or shrink by hundreds of billions of tons in a season.

The results aren't a complete surprise: scientists had already reported that the westerlies which feed the Karakoram have brought cooler, cloudier and snowier conditions to some regions (Archer & Caldeira, 2008) which may or may not be a long term effect but could partly explain how the very highest glaciers are storing water (Scherler et al, 2011).

The big picture

We now have the first global map of glacier weight change. The ice sheets are doing much worse than 2007 predictions and glaciers in most of the world are doing just as badly as thought. However, glaciers in the high mountains of Central Asia appear to have been stable for 8 years when old measurements would have expected 400 billion tons of ice loss. Meanwhile, over 4.2 trillion tons of ice have melted worldwide over 8 years.

2003-2010 is a short time though, so it's too soon to say anything about what will happen next here.

Seas are rising faster than computer simulations had expected, and these simulations are also lower and slower than has happened in the past (Vermeer & Rahmstorf, 2009). It's possible that the simulations didn't properly include the processes that shrink ice sheets so these results are consistent with faster future sea level rise. Figure 4 shows that the rate of melt in the big ice sheets is much larger than the swings caused by seasonal weather and the long term trend is obvious.

 

 Figure 4 - Change in the ice mass of Greenland (blue) and Antarctica (orange). Notice how the trend is much larger than seasonal changes, and how each vertical dash is now 200 billion tons, versus 100 billion for the glacier graph in Figure 3.

Many of those gushing over this new scientific work have also claimed that global warming has stopped. In Figure 5 we've worked out how much energy was needed to melt the ice that's gone since 2003 and wondered what would happen if that heat had been put into the atmosphere instead. The calculation assumed a constant rate of ice loss and used the latent heat of fusion for water. The heat is enough to warm the atmosphere more than 0.3 C in 8 years - faster than atmospheric global warming since the 1970s.

 Figure 5 - The blue circles are the changes in heat content of the atmosphere (estimated from NASA GISTemp global data) over a period that some say global warming has 'stopped'. The red line adds the heat that has been used to melt ice over the same period.

When you look at the full picture, you see that the Earth is still building up heat and claims to the contrary rely on selectively ignoring data. The good news is that the highest mountains in Asia seem to be almost 50 billion tons a year better off than expected. But this is small change next to the 500 billion tons a year being lost elsewhere.

 

A calculation error was pointed out by the commenters Eric (skeptic) and Sphaerica. This was noted and corrected on 25/02/2012. Figure 5 was changed and the penultimate paragraph also corrected.

 

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Comments 51 to 100 out of 100:

  1. A change in pressure, such as increaseing pressure in hydralics, will generate heat.

    My send was too quick.

    A change in pressure, such as increaseing pressure in hydralics, will generate heat. The heat generated is a result of an external force tho, and work is being done, hence the generation of heat.
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  2. Sphaerica#49:

    Thermal expansion varies with temperature, not with quantity of heat added. So you are correct, a fixed quantity of heat added to a bucket will result in a higher percentage of volumetric expansion than in a pool.

    Unless I am reading this table incorrectly, the coefficient of volumetric expansion for sea water increases with pressure, but decreases with temperature. Result: not much difference between warm surface water and cold depths.

    Compare coefficients of 244x10-6/K at 0C and 1000 atm pressure (deep water) vs 250x10-6/K at 20C and 1 atm pressure (surface).

    But I take issue with the prior comparison to warming a test tube, resulting in all vertical expansion. Continental shelves do not have vertical sides; the areal inundation of just a few meters of sea level rise is very large.
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  3. Sphaerica: I'm not at all certain of myself here, but my initial point was that if you add enough energy to a bucket of water to raise it by 1 degree, will that expand as much as if you added that same amount of energy to a pool of water?

    Hmmm... not sure if that is the right question! In the case of the ocean the bucket (upper levels) and pool (lower levels) have the same surface area. So the better question might be "if you add enough energy to a bucket of water to raise it by 1 degree, will that expand as much as if you added that same amount of energy to a bucket of water that is deeper?" To which my answer would be "Yes" (as far as I understand it) even though the temperature of the water in the bucket rises less.

    "The question was, given that level of pressure, would an increase in temperature result in an equivalent or lesser increase in volume compared to a liquid at a lower pressure."

    Water at a higher temperature (up to 45c) is even less compressible so the effect of high pressures really has no significant effect on what happens when water is warmed slightly in the deep oceans.

    All of this may be moot, however... your graph of decreasing sea level trend does not seem to take into account other "noise" factors, such as the effects of ENSO events. Are you certain that the decreasing trend you see is real?

    This data set has the intra-annual seasonal effects removed and my 12m moving average removes monthly noise. However it does include the effect of any ENSO events. Because the analysis is done over 5 years any ENSO "spikes" or "dips" are somewhat delayed. For instance the El-Nino in 1998 is reflected in an up-tick in the graph in 2003 (this was confirmed to me by the University of Colorado).

    I am certain the downward trend is real but uncertain as to its cause. The most likely explanation would appear to be a reduction in the rate of rise in heat content of the oceans. This seems to verify the graphs of ocean heat content that show a levelling off in the most recent period.
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  4. Muoncounter: "But I take issue with the prior comparison to warming a test tube, resulting in all vertical expansion. Continental shelves do not have vertical sides; the areal inundation of just a few meters of sea level rise is very large."

    Point taken, but we are talking about a rise of just a few millimetres not metres. I doubt the reduction in the rising trend has anything to do with "inundation" of river deltas at these tiny levels. It is much more likely to do with the temperature of the oceans not rising as fast.
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  5. "ENSO has no effect on the volume of water in the ocean"
    - yes it does. The recent removal of water to land for instance in the La Nina, affecting sea level.
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  6. scaddenp:
    A La Nina or El Nino event is only noise in the rate of rise of Sea Level.

    Even if you considered last years La Nina to be wet, the water has long since gone back to the ocean.

    We know with certainty that Greenland has lost ice mass. As a percentage of total mass, the loss is very small but the result is still a loss of mass and an increase in volume of water in the ocean.

    This is a long term trend that is not changing.

    The rate of SLR has slowed down over the past 5 years. ARGO data, while short, shows a reduction in THC of the oceans in the 0-700M volume.

    As you can see from the following link, even a 10% increase in freshwater is not a significant amount when looking at all of earth's water.

    The Water Cycle
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    Response:

    [DB] "ARGO data, while short, shows a reduction in THC of the oceans in the 0-700M volume."

    Kindly provide a link that supports this assertion...

  7. Matthew L @48:

    1) Your assumption of rigid constraint of the Ocean on all sides is incorrect. The Ocean floor (except over continental shelves) is a thin layer that flexes with the addition of further mass to the Ocean. The effect is to slowly push magma from under the Ocean floor to under the Continental crusts, thereby pushing them up.

    With the reduction in steric sea level rise over the last few years, and the increase in sea level rise due to the melting of glaciers, ice sheets and ice caps, this will have been a more important effect over recent years. Unfortunately I am unable to quantify it for you, and it will explain only a small part of the reduced rate of increase of sea level.

    2) There has been a distinct decrease in steric sea level rise over recent years. That is due in large part to the deep solar minimum over the period 2008 - 2011. In fact, from the 2001-2002 peak, TSI has declined by about 0.25 W/m^2 averaged over the Earth's surface, or about a quarter of the average Top Of Atmosphere energy imbalance over the last few decades. Evidence suggests a further 0.25 W/m^2 reduction from other sources since about 2004 with possible reasons including the impact of aerosols from industrial expansion in China and India, possible slight changes in TOA energy balance due to the effects of ENSO, or even a very slightly enhanced solar effect due to Solar specific feedbacks. SFAIK, the exact balance of reasons is still unknown, and nor is it known that all possible candidates are even being discussed.

    3) Finally, the very large dip in sea levels from 2010 - 2012 is attributed to increased land storage of water due to the very wet 2010-2011. According to the IPCC, 100 Gigatonnes of water will result in 0.28 mm of sea level rise. The dip is just over 5 mm at its deepest, and therefore represents just over 2,000 Gt of water stored on the land surface.
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  8. Well Camburn, I thought we were talking about change at the noise level.
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  9. DB@56:
    Refer to Rob Painting at 29 of this thread.
    He posted the temperature data of the 0-700M volume.

    Scaddenp:
    Your comment made me smile......you are 100% correct @ 58.
    We are talking abotu change at the noise level.

    However, the thought that the La Nina changed the rate by much is shown to be not correct by the link that I posted showing the distribution of fresh water on our planet.
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  10. Camburn, if the entire Antarctic ice sheet and the Greenland ice sheet where to melt, that would raise sea level by approx. 66 meters. According to the site you linked to, surface water represents just 0.4% of total water in ice sheets, ice caps and glaciers. In other words, if all surface water was returned to the Ocean without replacement, it would raise sea levels by 280 mm. Conversely, a 6 mm fall in sea level only requires a 2.1% increase in total surface water, based on the information provided by your link. I fail to see how your link shows the 2010 La Nina could not have increased total surface water by 2%.
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  11. Tom:
    That 2% would have long been back in the oceans. And 2% amounts to .051mm, a very small amount of short duration. Even considered as noise, such a small change would be vitrually undetectable.

    On a short term noisy timeline, the rate of change of SLR has slowed.

    One can't derive any long term conclusions as to why, or if this trend change will continue.

    Using the information available, about the only logical conclusion that one can draw is that the OHC has declined at this time.

    The only other conclusion would be that the ocean bottom has developed a new hole somewhere that we do not as of yet have knowledge of happening.
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  12. Camburn - "...about the only logical conclusion that one can draw is that the OHC has declined at this time."

    Actually, since the rate of change of SLR is still positive, still higher than the ~1.3mm/yr pre-industrial level, the strongest statement that could be made is that OHC, while rising, is not rising as fast as it has in the recent past.

    I will note that decadal variances in sea level rise are quite obvious in the last 150 years while showing accelerating sea level rise:

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  13. KR:
    The average SLR between 2005 and 2010 is 1.3mm/year. Page 8 of the following link.

    From the following paper:
    An excellent analysis of where we are concerning current SLR

    I have not read a good reconstruction of historic sea level on a global level. The contents of the above link show the difficulty in using a few sites to try and reconstruct sea level rise rates etc.

    The above also discusses the difficulty using satillites, and hopefully, most of these issues have been resolved with the improvements of combining data sources to achieve a clearer picture.

    We know that the ice mass loss of Greenland, and potentially Antarctica, has not slowed down.

    With the above in mind, it shows that something has slowed down the rate of rise of SL. ARGO data shows us that, at least in the upper boundary of the ocean, OHC has not increased.

    That assumption is also demonstrated in the observed balance of radiation presented in a paper presented on this site.
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  14. Camburn @61:

    If the Antarctic Ice Sheets melted, they would raise sea level by nearly 60 meters (60,000 millimeters). If the Greenland Ice Sheet melted, it would raise sea level by 6.5 meters (6,500 millimeters). (I choose not to use the 80 meter estimate from the later source in order to be conservative.)

    From your source, surface water represents 0.3% of all freshwater, while Icecaps and Glaciers represent 68.7%. That means there is only 0.44% as much water in surface water as there are in Icecaps and Glaciers.


    Rounding down, we therefore have that the contribution of 2% of surface water to sea level would be 0.02 x 0.004 x 66000 millimeters or 5.28 mm. I have no idea where you got your 0.051 mm figure from.

    For comparison, here is the Jason 2 data for sea level rise:


    (AVISO

    You will notice the approximately 6 mm dip and recovery that dominates that later part of the graph. Clearly a 2% increase in surface water would be enough to explain all, or nearly all of that dip.

    Not only are you wrong about the magnitude of the effect, you are wrong about the rapid recovery. Much of the water from the January 2011 Queensland floods, for example, still remain happily below sea level at Lake Eyre. It took several months to get there because of ht low gradient, and because of that low gradient, most of the rest of that water that was not captured in Qld's many dams has only recently reached the sea at the mouth of the Murray river. Much of the water will also have replenished surface aquifers, soil moisture content or been stored in newly refreshed plant life.

    The notion that rainfall immediately runs of to the sea is simply bizarre, and as a farmer you should know that.

    However, as noted, and although it took about two years, the sea level has recovered, and most of that water has now returned to the sea.

    There remains therefore only your strange contention that so large a dip in sea level (in the short term) could have no effect on short term trends. The contention once considered is clearly seen to be false.
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  15. Camburn @63:

    "A number of climate not-so-skeptics have been exploiting global sea level data in their latest attempt to hide the incline. Skeptical Science readers will be very familiar with the tactics the "skeptics" use to make this argument:

    Cherrypick a very small amount of data during which the short-term noise has dampened the long-term incline

    Ignore the long-term trend

    Refuse to examine the reasons behind the short-term change"

    Dana Nuccitelli

    And here are the colours Camburn persists in turning a blind eye to:

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  16. Tom:
    Australia is a wonderful country, but the small amount of water stored in Lake Eyre doesn't amount to much on a global scale.
    The flooding on the Mississippi water shed in 2011 has all reached the oceans as the lake levels of the dams are actually lower now than early spring of last year. Also, the water in the Red River Basin has been gone for months.

    That aside, the 0.3% of global water in the surface pool does not all go to the oceans. It would have to do so to achieve the 6mm dip and recovery that you showed.

    Where I got the 0.05mm from was as follows:
    2.55 rate of sea level rise. Rivers have approx 2% of the 0.3%. Assuming that all the rivers ran dry, take the 2.55mm x 2% (which would still be too large, but I was trying to show how small the contribution is)....you get 0.051mm.

    We have a finite water budget on earth. The link I provided shows the distrubtion of that water presently.
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  17. Camburn - 5 years is a very short time period considering year-to-year variance, variance which has been seen over the entire ~150 year close observation period for sea level rise.

    Unless you can show some statistical significance for it, I would have to consider that 5 year time period far too short for trend analysis. And a 15 or even 10 year period (let alone longer ones) still shows considerable SLR.
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  18. Tom:
    We are talking about the short term trend change in SLR. WE are not discussing the long term trend as scaddenp pointed out at 58.

    I am not ignoring the pictures......

    I am very familiar with the Upper Mississippi water shed and the Red River Basin water shed of North America.

    The water that fell in 2010 is long gone. And while we are talking colors, it is very possible that the drought conditions in the Mid West and South Central canceled out the precipitation in the Upper MIssissippi water shed.

    Also, when looking at blue.....remember that the blue on Greenland is an increase.....it snowed a lot there and will stay on the ice cap for awhile. Overall, tho, Greenland has lost mass so that blue on Greenland would not be an increase in mass, but an increase in SLR.

    The question that is being discussed is why SLR has slowed in the past 10 years. And it has, skeptic or not, that is what the data is showing.

    Whether this slowing of the SLR trend persists is a seperate question all to itself.
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  19. KR@67:
    I agree with you 100%.

    What I do have confidence in, is that the present state of the measureing instruments is the best we have ever had.

    The time frame of these instruments started in approx 2003-2004. That is the trend we are dealing with, to detect with a much higher degree of accuracy than could have been done prior to this time.

    The long term trend established with the data that was available at the time has not changed in any statisically significant way.
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  20. Camburn @66, I specified 2% of surface water. I did the calculations, and did them correctly. For you to switch that to 2% of river water in your calculation is simply bait and switch. To do so without specifying that you had changed the quantity measured, as you did in post 61 is blatant trolling.

    Given that there is no reason to think that excess rainfall would all be stored in rivers, and not in lakes and swamps (for example), there is no plausible basis for your change in the measured quantity. Frankly, I think the only reason you changed from surface water to river water only (without mentioning that you did so) was to minimize the value thus calculated.

    I need only to point out that while it may be drying in parts of the US, in Qld is is flooding again for the third record setting flood in 24 months (although not as extensive as the previous two). Further, I need to point out that the US is a small part of the world as well. I used Qld only to illustrate the many types of processes that can, and do delay the return of rainfall to the ocean.

    Finally, you have clearly established to my mind that you are just trolling on this thread. Therefore I have no more interest in discussing this subject with you.
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  21. Camburn - Then what we are looking at with the short term data is simply a more accurate view of short term variance, not a long term trend.

    The GRACE data is very interesting, and certainly shows mass accumulations in numerous areas over the last few years. It will be interesting to see how that data evolves over time. But it certainly indicates water accumulations on land (due most likely to La Nina conditions) persisting for >year durations.
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  22. Tom@70:
    Your assumption was surface water. You used it all.
    I looked at what surface water was composed of....swamps...etc.
    I took the fluid water.....the water that would be considered non-stationary.

    I am fine with you not discussing this subject with me.
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  23. KR@71:
    Yep.....short term varience, as there has not been enough time to change the long term trend.

    As far as water accumulating on land tho...in North America is wouldn't persist for years. From Tom's post, Lake Eyre would seem to be an exception to normal water shed activity as it is below sea level. That would make a difficult drainage basis, and I wish the best for him and folks that live near there.
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  24. I notice that Camburn stands firmly behind his opinion that rainfall will not effect lake levels. No more need be said.
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  25. Camburn - The GRACE data (which I suspect still is in the ground-truth calibration phase) certainly shows North America as not a major influence. But Australia and Brazil have huge mass accumulations, as do portions of Greenland and northern Russian regions.

    Always important to look beyond the local neighborhood...
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  26. KR:
    Yes, portions of Greenland do, but according to Grace data, overall Ice mass on Greenland is continuing to delcine, so that contribution must be ignored, and rather the data demonstrates that even with the Northern Greenland gain, the over loss of ice mass is a steady contribution to SLR. The Amazon basin of Brazil was actually in a moisture deficit, as was Argentina and that area.

    As far as Columbia and Venezala, (the blue area of South America), that area is also well drained.

    I think the Grace data is now pretty good. There was a paper published not long ago of which I didn't save, and can't find the link, that showed some problems with the algorythems and one would hope those have been adjusted.

    Tom@74:
    Rainfall will affect lake levels, but for only a very short time period in most circumstances. Lake Eyre is an exception, and should not be extrapolated to other large water shed basins.
    The Upper Mississippi water shed, North Central Great Plains area, drains fast and hard.
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  27. Camburn.
    You seem to be assuming that increased rainfall over various regions will be returned to the oceans relatively quickly. If extra rainfall drains quickly across surface soils into fivulets, streams rivers etc yes. But you seem to be discounting two other factors. Increased water uptake by dry soils and sub-soils that doesn't drain away at all. And water uptake by the land but doesn't flow relatively quickly to the sea but starts to percolate down and recharge aquifers.

    Your presumption of relatively quick transfer of increased precipitation back to the oceans sounds rather simplistic.
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  28. Matthew L - "My problem with the missing heat being at the bottom of the ocean is that heat will expand the sea wherever it is hidden. Surely the sea would be expanding more quickly rather than less if both the temperature of the deep oceans was rising and the glaciers melting? I have seen the explanation of recent flooding due to La-Nina but am sceptical that this could account for such a large and sustained decline in the rate of sea level rise."

    It's doubtful that thermal expansion during the "noughties" was higher than the 1990's. Certainly James Hansen's work shows otherwise. Glacier melt seems to have reached a point where it has accelerated through the noughties, even as ocean warming was progressing at a slower rate than the 1990's, which suggests it has passed a 'tipping point' of sorts.

    A combination of slower ocean warming in the noughties, combined with strong La Ninas at the end of the decade (more rainfall over land - and lower sea levels) have contributed to the sea level trend over the last 5 years. But it's unlikely to last. The solar cycle will see more ocean warming for the next 3-5 years, and shift back to El Nino will see more short-term sea level rise.
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  29. The bulk of extra groundwater runs off in a matter of months. See, for example, figure 5 here: http://pubs.usgs.gov/wri/1996/4179/report.pdf
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  30. Eric (skeptic) @79, you surely are not taking data from one location on one small stream in a hilly (and hence well drained) area and extrapolating to globally averaged properties, are you? Because that would be cherry picking of exceptional proportions.
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  31. Tom, I am taking major rivers and looking at the exponential decay of their flow after rains and after wet periods. Surface water decays in days. Ground water takes weeks to several months, but no more than that. For example the Potomac a major river near me has a few month decay at most (log scale):
    http://waterdata.usgs.gov/nwis/dv?cb_00060=on&format=gif_default&begin_date=2010-02-27&end_date=2012-02-27&site_no=01646500&referred_module=sw
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  32. Eric wrote: "Surface water decays in days."

    Ummm... you've never seen a lake? Or snow?

    Technically if they ever 'decay' (by which I assume you mean the mass of water decreases) at all then whatever time frame that takes place in could be measured in "days"... but the '~11,680,000 days' the water of the Great Salt Lake has existed thus far would be a fairly ridiculous method of measurement. It is decaying, and presumably will eventually disappear entirely... but we are talking about alot of days.
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  33. Eric (skeptic) @81, the amount of time from rainfall to run off to the sea depends critically on a number of facts of geography which are highly variable across different regions in the world. For example, rainfall in Ethiopia can take half a year to reach the sea even as direct run off due to the shere length of the Nile through which it flows. Rainfall from around Texas, Qld can take as much as a year to reach the mouth of the Murray. That excludes water that enters aquifers. Water entering surface aquifers in central Qld will never reach the sea by drainage. Therefore a simple assumption that rainfall will reach the sea in weeks or a few months at most (as made by Camburn) is completely unwarranted as a generalization. (I am not concentrating on QLD because it is typical, but only because it is familiar.)

    Furthermore, Camburn's argument that the rainfall would all reach the sea in short duration is premised on the absurd assumption that most of the rainfall occurred at the same time. Because floods are not typically coincident, major flooding in different regions at different times can result in increased global surface water for extended periods. This applies even to individual regions. Victoria experienced major flooding in 2010, record breaking flooding in early 2011, and is now threatened with new record breaking floods. I have elsewhere detailed Queensland's new record for flood effected area in March of 2010, which was smashed in Dec 2010/ Jan 2011 by almost a factor of three, and has been followed up by record breaking flood depths (not extent) in new floods in South West Qld in Feb of this year. My list is not exhaustive for these two states.

    In the face of records like that, Camburn's argument about runoff times, in addition to failing on its merits, is clearly seen for what it is - an evasion.

    Finally, all of this debate is beside the point. If you look at the GRACE image @65 above, you will see it is a years worth of data. That is, averaged over a year, Australia had the equivalent of a layer of water 3 to 5 cms across its entire surface. Of course, most of that water was in ground water, or fuller rivers and lakes, and of course in periods of intense flooding. But it is the effect over a year. In the face of that, arguing that water runs of in a week or so so it cannot have a year long effect on sea levels is obtuse, to say the least.
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  34. Tom, do the drier areas of earth offset the wetter ones like Australia? Is there anywhere I can get totals? Specific to your arguments above, I am mostly looking at when the bulk of the water exits through the rivers. There is an exponential decay and you and I have to identify which part of the curve we are talking about. The higher the starting point, the faster the decay. There is no doubt, for example, that the bulk of the waters of record floods that you talk about drain very quickly. OTOH, a look at the mighty Mississippi at St Louis shows a few years of higher flow at a time and I need to identify how much of that is a wet pattern and how much is the decay from previous wet periods.
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  35. Eric wrote: "I am mostly looking at when the bulk of the water exits through the rivers."

    The bulk of it doesn't exit through the rivers. Average annual precipitation on land is about 26,000 mi^3 of water. Average annual evaporation from land is about 17,000 mi^3 of water. That leaves ~9,000 mi^3, a little over a third, to be lost through runoff into rivers and other means (e.g. subsurface flow). This assumes balanced flows, which is true for a long term average but not for individual years (such as the recent exceptionally wet years).

    Also: "There is no doubt, for example, that the bulk of the waters of record floods that you talk about drain very quickly."

    'Very quickly' is a meaningless term without some sort of frame of reference. The few months it usually takes for half of the precipitation which falls on land to be removed is indeed 'very quick' on a geological time scale.
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  36. Eric (skeptic) @84, some of the floods of 2010 will have drained very quickly. The Pakistani floods, for example. But except on the coastal fringe, the Australian floods do not. As I have noted elsewhere flood water in Queensland takes 9-10 months to reach Lake Eyre (for the more western waters, and a similar period to reach the mouth of the Murray (for the more Eastern waters). Even the Victorian floods took up to a month to drain away, and probably a couple of months to reach the mouth of the Murray. That is probably atypical, but as the example of the Nile shows, not exceptionally so. It is certainly far from atypical once you include the effect of frozen precipitation not thawing until summer (in some regions) or of dams and the filling of lakes, or in one instance the partial refilling of the Aral Sea.

    With regard to the overall balance, unfortunately I do not have figures. The graph shown above was prepared by Josh Willis of NASA, who indicated that it at least partially explained the drop in sea level. I assume, therefore, that he has done a balance which shows a net accumulation of surface water in 2010. I am not aware of its having been published.

    Finally, this will be my last post on surface waters effect on sea level on this thread, where it is significantly of topic. If you want to continue the conversation, may I suggest the thread of my first link.
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  37. 1. It is very obvious when looking at the map above that the excess/deficit water in North and South America basically cancel each other out.
    2. Even tho the Northern Area of Greenland is accumulating water, Greenland as a whole is loosing mass. This loss of mass has not slowed down even tho it has snowed more on the northern area. The blue area of Greenland then becomes a net contributor to SLR, not a deficit.
    3. According to Tom, Australia is a basin and has very slow run off. I will believe him without requesting documenation, as local knowledge and observations provide 1st hand evidence.
    4. The drought areas of Asian and Africa bascially cancel each other out as they are very simliar in magnitude. One a deficit, one a surplus.

    The only exceptionally wet years appear to have affected Australia, but on a continental basis of other continents, the dry and wet areas appear to cancel each other out.
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  38. I must congratulate Camburn on having so advanced an eyecrometer; and congratulate him still further for having the foresight of adding a widget that always allows him to see only what he wants to see.
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  39. Camburn - Visual assessment of that map will not be reliable. For that you need to actually run the numbers, not the eyecrometer.

    Lake impoundment, ground water impoundment, ongoing precipitation increasing the water mass despite increased drainage - none of these mass shifts are 'single events' which might then drain, they are part of a pattern of precipitation shifts due to the recent La Nina's.

    I would look for Willis to publish on the topic. In the meantime, I would take his opinion as to mass shifts to land, as supported by his data, to indicate a partial explanation for recent reductions in SLR. And until/unless you have contradictory global data, that's the best information we have.
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  40. Tom Curtis - "With regard to the overall balance, unfortunately I do not have figures. The graph shown above was prepared by Josh Willis of NASA, who indicated that it at least partially explained the drop in sea level. I assume, therefore, that he has done a balance which shows a net accumulation of surface water in 2010. I am not aware of its having been published'

    A paper by Carmen Boening (NASA JPL) on this subject should be out soon. Last time I checked she informed me it should be out in the early part of this year. I'll incorporate it into the advanced rebuttal of: Sea level fell in 2010.
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  41. Tom@88:
    That you for the compliment. Always appreciated.

    The widget works well for areas that I know about.

    And I do know the Mississippi watershed veryyyyy well, as well as the Red River Watershed.

    Greenland is self explanatory.

    South America is in my farm news eyecromiter daily, as well as Asia because Asia is a large buyer of commodities.

    Thanks again.
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  42. @ Camburn

    Could you be a good chap and elaborate on your claim you made earlier that
    "ARGO data, while short, shows a reduction in THC of the oceans in the 0-700M volume."
    Looking at the source you reference (comment 29)
    "DB@56:
    Refer to Rob Painting at 29 of this thread.
    He posted the temperature data of the 0-700M volume."
    For the life of my sainted mother, all I see is the graphic Rob P. posted from Roemmich and Gilson 2011, but not any data. If memory serves, Roemmich and Gilson 2011 focus on the Argo 2005-2010 dataset, of which one might construe Rob P's graphic to be representative.

    Can you share with us the significance testing you used to examine the data from Roemmich and Gilson 2011? I presume you actually went back to the source data itself to make your claim...right? It would be a deucedly tight bit to have the stones to use that, what is it called again? Eyecrometer? In lieu of actual analysis, what?

    Also, when you impute that there is a reduction, to what are you comparing the 2005-2010 dataset? Because it would seem to either nothing or itself. Naught very scientific of you, old bean.
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  43. CBDunkerson, thanks for the info on evaporation. I would argue that is part of the exponential decay of the bulk of excess rainfall measured in river levels (i.e. when the rains return, the preceding evaporation will dictate river levels.) Australia seems to have some fascinating exceptions in some cases being low and flat, I'll have to comment more in that thread. In the meantime here's the Mississippi which I saw in 1993 in St Louis; needless to say it left an impression.

    http://waterdata.usgs.gov/nwis/dv?cb_00060=on&format=gif_default&begin_date=1993-01-01&end_date=1997-01-01&site_no=07010000&referred_module=sw

    If the link above works it should show the relatively rapid decay of very large volumes of flow, but also a slow decay, on the order of a year or two from the enormous flood of 1993. I don't know how much of that is rainfall patterns and how much is water storage. But it does reflect both the direct runoff and the indirect evaporation (that lowers direct runoff); both of which lower the amount of water stored.
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  44. Prof P. Body@ 92:
    Yes, Rob's graphic at 29 would have used the data that supports slide number one of the following site.

    NODC global ocean heat and salt content

    You will note that the graph confirms my statement concerning THC of the 0-700M volume of the ocean.

    The trend of surface sea temperature would also seem to confirm the 0-700M OHC.

    SST 2003-2012
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  45. Camburn old chap, you do realize, don't you that (even if on some ephemeral level) that you are just play-acting at analysis here.

    You specifically quote Mr. Rob P's graphic but miss-state what it shows. The referee called you one it and you just offer up bluster instead of substance. And now, without apparently even reading the study forming the basis of the graphic in question, you employ bravado and presumptuous hand-waving in your above comment.

    I do note your statement...and that your newer links simply do not support it. If you think analysis consists of "eyeballing" (as the Yanks seem to refer to it) a graph then you simply do not understand anything about science or statistical analysis (even my half-witted assistant Sherman gets this point).

    Fake-skeptic-fail.

    This august forum deserves a better class of troll.
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  46. Tom,

    Camburn needs to learn above a little concept known as "non-contributing areas" and infiltration (that is how aquifers are recharged). There seems to be an assumption that all the incident precipitation becomes runoff. That is obviously not what happens.
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  47. Prof. P. Body @95,

    I'd like echo/second your thoughts. Additionally, first people should use the correct nomenclature, traditionally "THC" refers to the thermohaline circulation. Second, the oceans are obviously significantly deeper than 700 m. Third, it is strange how fake skeptics continue to focus on statistically insignificant short time periods when we know the increase in temperature and OHC is not going to be monotonic-- they will still be playing that game when knee deep in water. It is called denial. Fourth, as I show below, you are correct, the links provided do not support their claim. One wonders whether or not they will cede that fact?

    So, regarding this as yet unsubstantiated claim.

    "The rate of SLR has slowed down over the past 5 years. ARGO data, while short, shows a reduction in THC of the oceans in the 0-700M volume."

    This is a badly worded argument. They speak of last 5 years of sea-level (since 2007), but then go on to mention the ARGO data which has been providing more-or-less uniform global coverage down to 700 m since the beginning of 2005 (see here), so let us use those data. I downloaded them from here. So the fake skeptics can check the numbers themselves.

    Since 2005 the 0-700 m global OHC has been increasing at a rate of 0.28x10^22 J/year, or increase of about 1.97x10^22 J between 2005 and 2011. So the claim that 0-700 m OHC is decreasing is demonstrably false.

    Further, since 2005 the 0-2000 m global OHC has been increasing at a rate of 0.732x10^22 J/year, or an increase of about 5.13x10^22 J between 2005 and 2011.

    But this is all for a very short period, so caveat emptor.
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  48. Rob Painting #90. Thanks for the heads up on the paper by Carmen Boening that is due. I will keep an eye out for it. Unlike Camburn I don't doubt that sea level and OHC continue to rise, but it is clear that the rate of rise has slowed in both cases over the last 5 or so years.

    I have argued with fake-sceptics elsewhere who deny that the Earth is warming that the rise in sea levels is evidence that it is, in other words that the sea acts like a giant thermometer. Obviously things are much more complex than that but the depth of ignorance out there is staggering.

    Brilliant site by the way! We really need somewhere that deals with facts and real science rather than ill-informed speculation. I am new to posting here (been a lurker for a little while) and have a query on sensitivity / positive feedback (is cooling amplified as well as warming?). Is there a general thread / forum where I can post such questions?

    pps - Still extremely irritated by the use of such an old fashioned map projection in Figure 1. It does nobody any favours and could be read as a deliberate effort to mislead (obviously not your fault of course). There are plenty of much more informative alternative projections available so there is no excuse. Presenting information in maps and plans is a big part of my job, so I am very aware of how misleading and "political" maps can be!
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  49. Matthew L:

    I suspect an ideal approach is to seach for a thread relating specifically to sensitivity or feedbacks using the search feature at the upper left of each page on this site. For example, such a search led me to this page which is probably ideal for your purposes.

    Or the main page has 'newcomers: start here' and 'the big picture' links to their respective pages, which are probably good places to post such queries. Me not being part of the site team, though, you might take this particular suggestion with a grain of salt.
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  50. Matthew L, I'm curious as to why you don't like the map projection? Not equal area?

    Looks like a Miller Cylindrical to me. It's from 1942, but most map projections are older than that. All map projections necessarily have distortion, though some are more pleasant to look at than others.

    See here for more information.
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    Moderator Response:

    [DB] Speaking as a former professional nautical cartographer, the intended use of a map determines the projection used. For any global representation the projection choice is not ideal, as one has to represent a nearly-spherical object in a 2-dimensional plane. For global purposes, this is my representation of choice for the oceans:

    [Source]

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