Guest opinion: Dr. Tim Ball
Glaciers are in the news again. An article by James Hansen about Antarctica and another published by Geophysical Research Letters about Greenland raise the specter of sea level rise. They are purely speculative and don’t bear investigation, but that doesn’t matter because the headline is the objective. The wider purpose and the reason glaciers are the target is the upcoming climate Conference of the Parties (COP21) scheduled for Paris in November. Polls show the lack of public concern about global warming or climate change, which necessitated a return to a tried and successful alarmist strategy.
Hansen’s article focuses on the West Antarctic Ice Sheet (WAIS), which was the NASA focus from the start.
It didn’t take long for the verdict on the West Antarctic Ice Sheet to come in. “Unstable,” wrote Ohio State University glaciologist John Mercer in 1968. It was identified then and remains today the single largest threat of rapid sea level rise.
NASA promotes the same message now, except they are not as certain as Hansen.
Even as Rignot and colleagues suggest that loss of the Amundsen Sea embayment glaciers appears inevitable, it remains extremely difficult to predict exactly how this ice loss will unfold and how long it will take. A conservative estimate is that it could take several centuries.
NASA notes,
The region contains enough ice to raise global sea levels by 4 feet (1.2 meters).
The trouble is they don’t explain the calculation. Presumably, it is all the ice above and below sea level, but it doesn’t matter it is a big enough number to raise an alarm.
When I ask people what is wrong with global warming, they pause, often for some time, before saying, glaciers melting and sea level rising. It is foremost in their minds because of the exploitation in Al Gore’s movie. A study of public climate knowledge by Yale researchers illustrates the point (Figure 1).
The question is, “Which of the following can cause global sea levels to rise? (order of items randomized.)”
Figure 1
The correct answers, according to the Yale researchers, are given in brackets as True (T), or False (F). No wonder, in the overall results, 77 percent failed (Figure 2).
Figure 2
In the options, it is illogical to claim Arctic Ocean ice melting. If you claim Arctic sea ice causes sea level change, then why not Antarctic sea ice? Of course, claiming either is wrong because the ice is formed from seawater. There is likely a minimal sea level change because the ice is 6-7 percent greater in volume, but that is likely balanced because a portion of the sea ice is above sea level. Majorities of the 76 percent who believe melting Arctic sea ice raises sea level, likely do so because of the Gore deception. It is why the animation sequences of water over-running the land are a major part of the movie. He added the false emotive factor of drowning polar bears for a persuasive combination.
Other options for a source of melt water to raise global sea level are equally limited. They don’t mention Greenland or changes in the isostatic balance of land. The options and answers reflect the simplistic and fallacious arguments about sea level. Estimates of the total ice and water it contained produced a volume of water then added to existing sea level. Here is an exercise circulated for teachers by NASA in 1997.
Exercise: Determine the amount that sea level would rise, averaged around the globe, in response to the complete melting of (a) the Greenland ice sheet, (b) the Antarctic ice sheet, and (c) both the Greenland and Antarctic ice sheets.
The exercise offers some discussion of limitations but results in the following numbers.
(4) Calculate the sea-level-rise answers by dividing the water volumes determined in #3 by the global surface-water area determined in #1, thereby spreading the effect of the ice sheet’s water throughout the expanse of the Earth’s surface-water area. The answers are: (a) (2,343,728 cubic kilometers)/(361,132,000 square kilometers) = 0.0065 kilometers = 6.5 meters for the Greenland ice sheet; (b) (26,384,368 cubic kilometers)/(361,132,000 square kilometers) = 0.0731 kilometers = 73.1 meters for the Antarctic ice sheet; (c) 6.5 meters + 73.1 meters = 79.6 meters for Greenland and Antarctica together.
So there is the much-cited number of 79.6 meters (261 feet) that you add to existing levels. This sticks in students memories, despite warnings by the exercise creators that,
No knowledgeable person expects the Greenland and Antarctic ice sheets to disappear completely within the lifetime of anyone alive today, or within the lifetime of any of their children or grandchildren. Hence, the threat of a 79.6- meter sea level rise should not be seen as an immediate concern.
Thank goodness! But the relief is short-lived because the final paragraph identifies some limitations, but alarmism remains central.
These two ice sheets, however, are the largest potential contributors to sea level rise, and concern has been raised in particular over the possibility that the portion of the Antarctic ice sheet termed the West Antarctic ice sheet, lying largely in the western hemisphere, might be unstable and might decay relatively rapidly, perhaps even causing sea level rises of several meters within 100 years. Although such a decay is not highly probable, it is possible, and if it were to occur, the resulting several-meter sea level rise would cause serious economic and personal consequences to all highly populated low- lying coastal regions.
The actual exercise requires determining what percentage of the ice in the Greenland and Antarctic ice sheets is above sea level. Only melt water from that ice can contribute to sea level rise. An adjustment is necessary because the volume of the ice is approximately 6% more than the volume of the melt water. Then you have to calculate and allow for crustal deformation and isostatic adjustment for a reasonably accurate measure.
A few years ago, before it became politically motivated, Scientific American produced useful overview articles, such as John Eddy’s the Case of the Missing Sunspots. A March 1997 article asked, “How much of a threat are rising sea levels.
They concluded,
Now, 16 years after the NASA exercise, the 2013 Intergovernmental Panel on Climate Change (IPCC) Report Physical Science Basis Report concludes,
Therefore, the closure of the sea level budget to date does not test the reliability of ice-sheet models in projecting future rapid dynamical change; we have only medium confidence in these models, on the basis of theoretical and empirical understanding of the relevant processes and observations of changes up to the present.
The Report identifies some of the limitations.
They identify three categories of confidence, Low, Medium, and High. Do we assume that Medium is 50 percent? It is reasonable considering the limitations they identify.
Nevertheless, three central issues remained. First, the observed sea level rise over decades was larger than the sum of the individual contributions estimated from observations or with models (Rahmstorf et al., 2007, 2012a), although in general the uncertainties were large enough that there was no significant contradiction. Second, it was not possible to make confident projections of the regional distribution of sea level rise. Third, there was insufficient understanding of the potential contributions from the ice sheets. In particular, the AR4 recognized that existing ice-sheet models were unable to simulate the recent observations of ice-sheet accelerations and that understanding of ice-sheet dynamics was too limited to assess the likelihood of continued acceleration or to provide a best estimate or an upper bound for their future contributions.
Typically, the Summary for Policymakers (SPM) tells a very different story.
Anthropogenic influences have very likely contributed to Arctic sea-ice loss since 1979 and have very likely made a substantial contribution to increases in global upper ocean heat content (0–700 m) and to global mean sea level rise observed since the 1970s
“Very Likely” is 90 – 100 %.
It is another example of the deliberate deception created by great differences between the Science Report and the SPM.
It is impossible to discuss all the limitations of IPCC analysis of glacier changes that result in sea level change. Figure 3 from the IPCC AR5 Science Report shows the extent of the variables.
Figure 3
Science distinguishes between Mountain (Alpine) and continental glaciers. In reality, the creation and mechanisms are the same Temperature receives most of the focus and public understanding about glaciers. However, precipitation is equally important information and changes in what is called the Mass Balance of the glacier. The front of the glacier, called the snout in mountain glaciers, advances or retreats as much because of precipitation as temperature.
A glacier forms when some snow survives the summer melt. That can occur because of lower temperatures or an increase in the volume of snow. Figure 4 shows the dynamic balance of a glacier.
Figure 4
The Equilibrium line moves with temperature but because of the gradient it takes a considerable change for it to move much and affect a significant area. A more significant factor is the change in the amount of snow in the accumulation zone.
Obviously snowfall amounts vary in different regions and over time. This explains why glaciers in some regions advance while others retreat.
Scientists track glacial change by measuring individual glaciers and comparing their size over time with records of the local and regional climate. But measuring every major glacier on Earth would be a monumental task. Approximately 160,000 glaciers occupy the Earth’s polar regions and high mountain environments, and sending a team to each one every year would be costly and difficult to coordinate. In addition, although a few research teams travel to a few glaciers each year to measure ice depth, size, movement, and water content, the data from individual glaciers don’t necessarily reveal how other glaciers in the same region—much less in other parts of the world—are changing. Even glaciers within the same region can react differently to environmental changes. For example, while most glaciers in Glacier National Park are retreating, some are advancing.
The difficulty is biased reporting, as only retreating glaciers make the headlines.
NASA is planning for better knowledge of the mass balance of Antarctica with a satellite.
In 2017, NASA will launch ICESat-2, the follow-up mission to ICESat, which operated from 2003 to 2009. ICESat-2 will use laser altimetry to make precise measurements of glacier heights. Combined with the ICESat and IceBridge data records, the ICESat-2 measurements will allow for a continuous record of year-over-year change in some of the most remote regions of the world.
The problem is the height of an ice mass like Antarctica is not an indicator of changing size or volume. As the mass at the center of the glacier increases the outward flow increases, thus reducing central mass and height (Figure 5).
A 2012 article titled “Why ice loss and sea level measurements via satellite and the new Shepherd et al. paper are highly uncertain at the moment” spoke to the problems with the NASA claims.
The pattern created by the plastic flow of the ice is repeated in a Mountain Glacier, with sagging in the upper portion and bulging in the lower portion because of the plastic flow of the ice. (Figure 6)
Figure 6
Another study reported by WUWT indicates a significant increase in snowfall over the East Antarctic Ice Sheet (EAIS).
Enhanced snowfall on the East Antarctic ice sheet is projected to significantly mitigate 21st century global sea level rise. In recent years (2009 and 2011), regionally extreme snowfall anomalies in Dronning Maud Land, in the Atlantic sector of East Antarctica, have been observed. It has been unclear, however, whether these anomalies can be ascribed to natural decadal variability, or whether they could signal the beginning of a long-term increase of snowfall.
Sea level rise due to melting ice is the one threat of global warming that worked effectively with the public. As the Paris Conference looms the alarmists increase the potential threats to ensure that action is taken. Hansen is one of the most active alarmists who used his position at NASA GISS to push alarmism and misinformation.
A moment of serendipity occurred while researching this article. I typed the acronym WAIS into a search engine expecting West Antarctic Ice Sheet instead I got the Weschler Adult Intelligence Scale. Here is the definition.
… the global capacity of a person to act purposefully, to think rationally, and to deal effectively with his environment.”] He (Weschler) believed that intelligence was made up of specific elements that could be isolated, defined, and subsequently measured. However, these individual elements were not entirely independent, but were all interrelated. His argument, in other words, is that general intelligence is composed of various specific and interrelated functions or elements that can be individually measured.
It appears those studying WAIS are low on the WAIS scale.
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Hoping I missed where this was pointed out, but melting sea ice, as in below sea level ice unless there are Death Valley like below sea level land depressions in Antarctica and Greenland, will not raise sea level.
Pretty much because the molecular weight of water remains the same in all its physical states.
If you don’t believe this, pour yourself a glass of ice water and watch the level as the ice melts.
From the article above:
We need to expand this definition a little bit better.
Mountain glaciers = As drawn above. The glacier starts up high, snow and ice are deposited high, the glacier mass slides down (sometimes rotating as drawn when the valley slopes enough), and eventually melts out at low levels in the heat. The water will eventually run off to streams, lakes and eventually the ocean below. Resistance to flow is the slope of the valley, the roughness of the glacier valley, the resistance to flow of the glacier up higher due to the dead weight (mass and volume) of the glacier down low.
No surprises, right? About what you would expect, and what the elementary grade climate books explain.
This rudimentary diagram (cross-section) and explanation are correct ONLY for the short coastal glaciers around the Greenland periphery! The description works ONLY for the 5 – 15 kilometer coastal glaciers facing the sea AROUND the Greenland island and the West Antarctic Peninsula! Those glaciers – some 5-8% of the total icecap) do “flow downhill” to the sea, and – over time their mass flows as shown.
But for all of the 90% of Greenland’s interior icecap and vast majority of the East Antarctic land ice “glaciers”, this is incomplete and – because it is incomplete – it is very misleading. Central Greenland is surrounded (south, west, north, and east) by very high, bare rock mountains. All of the interior ice flows downhill – or tries to – as the diagrams above show. But the west-flowing ice trying to move “downhill” from the east coast mountain ranges is trapped by the east-flowing glacier ice flowing “downhill” from the west coastal mountain ranges. North-flowing glaciers are trapped by the south-flowing glacier ice. Thus, none of the interior ice can “flow downhill” in any direction – it is trapped in a bowl in the hundreds of kilometers between the coastal mountain ranges.
This trapped interior ice builds up over time (WWII airplanes were covered by over 200 feet of new ice and snow in just 50 years). Today, the central icecap is several thousand meters higher than the mountainous rocky edges holding it in, but the length of the slope from the interior to the coastal ranges is so small there is no movement. There is no effective gravity forces pulling it sideways and downhill – unlike a coastal or mountain glacier that NASA describes so fearfully..
Thus. even if the assumed 25 degree temperature rise required to “melt Greenland icecap” (or the East Antarctic icecap) were to occur somehow, the interior ice could not flow catastrophically out to sea as postulated by NASA. The water would have to refill the interior basin (now 1000 meters below sea level) and would have to “leak out” through the few valley passes left open.
I once caught an ice researcher being cagey about just how much of a bowl the Greenland Ice Cap is in. That the whole thing will suddenly slide or melt is an important meme for the fear and guilt based catastrophic alarm, and the deadly urge to action.
A CRESiS engineer no less. Bah!
========
The correct answer to this is “definitely true”. As ice freezes it preferentially excludes salt. Fresh water is less dense than salt water. A floating object displaces its own weight of water, which means a less dense object displaces less than its own equivalent volume of fluid. So a fresh water iceberg displaces less salt water in volume than its own volume after it has melted. So some water is left over and it raises the sea level.
The effect is tiny. But it is real, and it is certain. And the questionnaire is, as usual for alarmists, presented in a binary either/or way. “Scientists agree!!! Melting sea ice raises ocean levels!!!!” Don’t tell anyone you’re not talking about the bulk, 100% contribution, that land ice has. Oh no, just leave the fact that you’re talking about a minute effect unspoken, so people get the wrong take-home message from the facts. Also, respondents are left in a “catch-22” situation. Does someone like me, who knows the facts I just presented above, answer yes, or no? If I say yes, I contribute to the alarmism, if I say no, I show my ignorance of physics. So in short, the questionnaire is dishonest, biased, and unfair.
The facts are, close enough, melting sea ice doesn’t raise sea levels. Or, put another way, they make next to no difference (but not no difference).
The fact that Yale Researchers think it is just fine to claim that melting of “Sea ice on the Arctic Ocean” is True upsets me. If it all melted the direct result would be no increase in sea level.
According to paleoclimatology data, previous interglacial periods experienced about 110 meters of sea rise following past glaciation events. Since total sea rise of the current interglacial has been about 100 meters, seas will likely rise another 10 meters before the next glaciation period begins.
Sea rise during the 19th and 20th centuries were both around 6″/century (15 cm), and 21st century sea rise will likely be about the same, despite all the CAGW scaremongering. If current trends continue, we still have another 6,600 years before the next glaciation period begins.
Everyone should just chill before the BIG CHILL occurs 66 centuries from now…
Yes, future generations will have to adapt to sea rise, as they have over the past 20,000 years following the last glaciation period. Most of the sea rise occurred during the first 10,000 years of the interglacial period, simply because there was A LOT of glacier ice melting; i.e. 20,000 years ago, NYC was under 1,500 METERS of ice…. That ice is all gone now…
Hmmmm, the UN building under 1,500 meters of ice… how cool is that…
Another glaciation will happen again. All scientists acknowledge this certainty… CO2 has almost nothing to do with it one way or another. When the Milankovitch cycles turn to their cold cycles in about 6,000 years or so, the earth will enter another glaciation period, which will kill billions of people.
And so it goes….
Jimmy’s back!
How the hell can melting sea ice cause rising sea levels? Yale must be stupid.
The logic’s so clear
Only fools can’t realise,
That global warming causes
Sea levels to rise;
Called the ‘Invention Principle’,
It’s an indisputable law,
Don’t believe what I say,
Go check with Al Gore!
http://rhymeafterrhyme.net/ignore-the-flying-pigs/
The Yale study said that “melting arctic sea ice contributes to sea level” their reference in the appendix is to a paper that states the difference of volume is caused by the difference in the salinity. The exact quote is “ice melting (or freezing) affects a change in sea level of about 2.6% of the volumne of displaced water.”
So if we assume that under the last decade we have had a maximum of 26,000 km^3 of sea ice volumne in mid-winter and all of its volume is ‘displaced water’ then 0.026*26,000 km^3 of added volume to the oceans or 676 km^3 of volume to be added to the oceans. Now if we us 2/3 of the globe is covered in oceans and add that volume and using the radius of the earth at 6400 km then ΔV = 4πr^2Δr implying
676 km^3 = (2/3)4(6400)^2 Δr
yielding
676=3.43 x 10^8 Δr or Δr = 1.97×10^-6 km = 1.97 x10^-3 m = 1.97 mm total.
So the Yale professors think that if ALL the arctic ice melted that we should be aware of this massive swing of 2mm in sea level as an important ‘contribution’ to sea level rise, while they are actually worried about measuring sea-level change 3-12 feet.
Their standard of importance is anything that would affect something at the .006% level! Wow amazingly low bar.
Yet, even if the ice melts, since the weight of the ice already accounted for by Archimede’s Principle, their conclusion seems to be in error. Since the weight does not change, neither should the displacement. The only change should be due to thermal expansion of the melt water.
The slight difference is in the weight of the displace salt water = weight of the melted fresh water. But the density of saltwater and fresh water are NOT the same hence the volume is slightly different. (by 2.6%)
We need a timeline on when climate uncertainty was eliminated from science, science policy, and science news reporting. A detailed investigative book author along the lines of Robert Caro is in order on who, what, when, and where for the historical record on the new climate policy dark ages when doubt disappeared and how we got here.
BTW – really neat photo of the Netherlands up at the top of the thread. Most of the sea level rise has already occurred and there is very little left to go.
Thank you, Dr. Ball. This is a really helpful and valuable article.
(Needs a bit of editing for typos, though.
“Majorities of the 76 percent who believe melting Arctic sea ice raises sea level, likely do so because of the Gore deception.”
If that is a defining relative clause, and it looks like one, there should be no comma after “level”. If it is non-defining, there should be another comma before “who”.
“This sticks in students memories,”
Apostrophe required.
“In reality, the creation and mechanisms are the same Temperature receives most of the focus and public understanding about glaciers.”
The full stop after “same” got lost.
“I typed the acronym WAIS into a search engine expecting West Antarctic Ice Sheet instead I got the Weschler Adult Intelligence Scale.”
As did the semi-colon after “Sheet”.)