Two Comments on Antarctic Ice Accumulation

Jo Nova blogs on a study that claims the Antarctic continent is accumulating ice mass at a rapid rate. I have made two comments. One is opposing someone who claims that Antarctica is actually losing ice. The other is that the claimed rate of ice accumulation does not make sense against known data on sea levels.

Manicbeancounter

April 17, 2013 at 6:27 am · Reply

John Brooks says

I’m also interested that the mass of antarctic land ice follows solar irradiance. This makes perfect sense. However I can’t see why the effective of an increase in the greenhouse effect wouldn’t have exactly the same result.

Maybe you should look at the period covered by the graph John. There is an 800 year correlation of mass of antarctic land ice with solar irradiance, with the biggest movements in both prior to 1800. Insofar as the greenhouse effect is significant, it is nearly all after 1945.

And for some reason, I’ve got the idea in my head that antarctic land ice is decreasing.

Sure enough from the Carbon Brief link, this quote

Measurements from the Gravity Recovery and Climate Experiment (GRACE) satellite since 2002 have shown that the mass of the Antarctic ice sheet is decreasing at an average rate of 100 cubic kilometres every year – the size of a small UK city.

(emphasis mine)
The size of a city is usually measured in area, not volume. The ancient City of York, for instance, has an area of 272 square kilometres (105 square miles) and a population of 125,000. Or maybe they mean the volume of the buildings in a city? A famous building in New York is the Empire State Building. Not only is it quite tall it also has quite a large volume. Around 1,040,000 cubic metres or 0.001 cubic kilometres in fact. So does the Carbon Brief claim that a small UK city have a volume of buildings equivalent to 100,000 Empire state buildings? Or each average person in a small UK city occupies a building volume greater than Buckingham Palace?
Alternatively, does John Brooks quote a source that does not have a clue about basic maths?

Manicbeancounter

April 17, 2013 at 8:01 am · Reply

I think this paper does not stack up. I worked as a management accountant in industry for 25 years. One thing I learnt early on when estimating or forecasting was to sense-check the estimates. No matter how good your assumptions are, when estimating or extrapolating well beyond the data trend (where there is potential for error), the best check on the data is by reconciling with other data.
From the above

“The SMB of the grounded AIS is approximately 2100 Gt yr−1, with a large interannual variability. Those changes can be as large as 300 Gt yr−1 and represent approximately 6% of the 1989–2009 average (Van den Broeke et al., 2011).”

A gigatonne of ice is equivalent to a cubic kilometre of water. If the land ice volume is increasing, the water must come from somewhere. Nearly all of that water needs to come from the oceans.
Now for some basic maths. A gigatonne is a billion tonnes. As water has a relative density of 1.0, a tonne of water (1,000 litres) is a cubic metre. Therefore a gigatonne of water is a cubic kilometre (1000^3 = 1,000,000,000 = one billion).
A further factor to consider is the area of the oceans. According to my Times Concise Atlas, the total area of the oceans and seas (excluding the enclosed waters like the Dead Sea and Lake Baykal) is 325,000,000km^2. A cubic kilometre of water added to an enclosed sea of one million square kilometres, would raise the sea level by just 1mm (1000mm x 1000m = 1,000,000mm in a kilometre). So 325km^3 = 325Gt-1 of new ice accumulation above sea level in Antarctica would reduce sea levels by 1mm, or 2100GT-1 by 6.5mm.
Some of the ice accumulation will be on ice shelves, so the impact of 2100GT-1 extra ice per annum extra ice might be to reduce sea levels by just 5mm per annum. Also sea levels might be rising by a little less than the 3.2mm a year that official figures claim, but there is no evidence that sea levels are falling. Further, any net ice melt elsewhere (mostly Greenland) is only adding 1mm to sea level rise. So the rest must be mostly due to thermal expansion of the oceans. I think that the evidence for the oceans heating is very weak and of insignificant amounts. Even Kevin Trenberth in his wildest flights of fantasy would not claim the missing heat (from the air surface temperatures) adds more than 1-2mm to sea level rise.
What this study does show is that by honestly looking at data in different ways, it is possible to reach widely different conclusions. It is only by fitting the data to predetermined conclusions (and suppressing anything outside the consensus) that consistency of results can be achieved.

My scepticism on global warming stems from a belief that scientific evidence is strengthened by being corroborated from independent sources. Honest and independent data analysis means that wildly different conclusions can be reached. Comparing and contrasting these independent sources leads me to believe that the public face of the global warming climate change consensus massively exaggerates the problem.

Kevin Marshall

AR5 First Order Draft Summary for Policymakers – a few notes on pages 1 to 8

Alec Rawls has taken the brave step of releasing the first order draft of the UNIPCC AR5 Report. Anthony Watts has republished at Wattsupwiththat.

Although Alec Rawls published in breach of signed undertakings, I comment and quote the report in the public interest. There is more than a single, unequivocal, interpretation of the data. To claim otherwise is dogma. This dogma is being used to justify policies that promote net harm to western economies, particularly the poorer and more vulnerable sections of society. In the name of this dogma, impartiality is being annulled and dissenters called nutters.

I have started with some initial observations on the first eight pages on the Summary for Policymakers – the only bit that people ever read. Like utterings from the Kremlin on the 1970s and 1980s, the coded language says as much or more than the actual words.

Major points

  1. No admission of lack of recent rise in the surface temperature record.
  2. But the lack of recent rise is accounted for by a step change in the warming in the Southern Oceans.
  3. AR4 got it wrong on decreasing precipitation in the tropics (which underlay Africagate), and they got it wrong on increasing hurricanes.
  4. Sea level rise is not accelerating. In fact the recent rise since 1993 is similar to the 1930-1950 period.
  5. Global glacier melt is not accelerating. Himalayas do not even get a mention.
  6. Medieval Warm Period gains more recognition than the AR4. However, recent studies will render AR5 out of date before it even published.

Page 3 Lines 21-25.
On temperatures there is a cover-up of the recent lack of warming. They cannot admit that global average temperatures have not changed for 15 years.

Page 3 Lines 38-40. Precipitation in the tropics likely increased over the last decade, reversing a previous trend from mid-70s to mid-90s. The AR4 prediction of some African countries experiencing up to a 50% reduction in crop yields by 2020 (Africagate) was based upon a belief increasing extreme drought.

Page 3 Lines 46-48

Changes in many extreme weather and climate events have been observed, but the level of confidence in these changes varies widely depending on type of extreme and regions considered. Overall the most robust global changes are seen in measures of temperature {FAQ 2.2, 2.6} (see Table SPM.1).

Translation – Saying that an extreme weather events are evidence of global warming has no scientific validity. Best measures are of global temperature, which we can’t admit have been failing to rise.

Page 4 Line 14. An admission that previous IPCC reports got it wrong on tropical cyclones getting more extreme.

Page 4. Lot of stuff on Trenberth’s missing heat being in the oceans. Oceans have been warming since 1971. The lack of warming of air temperatures since the mid-90s could be accounted for by this comment on lines 36-37

It is very likely that the Southern Ocean has warmed throughout the full ocean depth since the 1990s, at a rate of about 0.03°C per decade.

The lack temperature rise is explained by the heating up of the oceans. Global warming is now confined to the Southern Ocean. It is imperceptible, so on the Southern perimeter it is not sufficient to have stopped the increase in Antarctic sea ice from extending slightly.

Then this

Warming of the ocean accounts for more than 90% of the extra energy stored by the Earth between 1971 and 2010. Upper ocean (0–700 m) heat content very likely increased at a rate between 74 [43 to 105] × 1012 W and 137 [120 to 154] × 1012 W for the relatively well-sampled 40 year period from 1971 to 2010. Warming has also been observed globally below 4000 m and below 1000 m in the Southern Ocean, in spite of sparse sampling (see Figure SPM.1). {3.2, Box 3.1, Figure 3.2, Figure 3.3}

The very likely heating of the Southern Ocean, is based on sparse sampling?

Page 4. Line 46. Seas have very likely become saltier. That is has become less alkaline. On Page 6 lines 30-31, Ph decline is 0.015 to 0.024 per decade over last 3 decades. Call becoming less alkaline “acidification”, which is inaccurate. Oceans are heading towards Ph neutrality.

Page 5. Glaciers are globally still shrinking. No mention of Himalayas, and no mention of global acceleration. Range is “210 [145 to 275] Gt yr–1 to 371 [321 to 421] Gt yr–1“. Omit to convert these to sea level rise. 210 Gt = 0.64mm. 421 Gt = 1.29mm (Oceans = 326.2m km2 & 1 Gt water = 1 km3). In old money, glaciers are contributing 2.5 to 5.1 inches per century.

Page 5 Lines 47-49. Sea levels

It is virtually certain that over the 20th century the mean rate of increase was between 1.4 to 2.0 mm yr-1, and between 2.7 and 3.7 mm yr-1 since 1993. It is likely that rates of increase were similar to the latter between 1930 and 1950.

Translation. Sea levels are rising but not accelerating. If sea levels are a lagged response to rising surface temperatures, then (using the HADCRUT3 surface temperature data) we would expect the rise in sea levels to level off in the next few years, unless there is continued warming in the oceans.

Pages 6 to 7 Long-Term Perspective from Paleoclimatic Records

There was a medieval warm period, despite what Micheal Mann and others said in 1998 and 1999. But the MWP is less than the temperatures at the end of the twentieth century. However, due to time schedules for acceptance into AR5, they ignore Christiansen and Ljungqvist April 2012 and Ljungqvist et al 2012. The later, despite including discredited proxies such as Briffa’s notorious Yamal data, quite clearly shows rom 120 proxies that the 10th century had higher temperatures than at the end of the 20th century.


Similarly the Esper et. al 2012 of summer temperatures in Northern Scandinavia will render this part of the report out-of-date prior to it being published.

In 2006 the UNIPCC could bring themselves to bend the rules to allow in a corrupt scientific paper that suited their purposes, but this time they ignore two strong cases that undermine their case. If there is an AR6 around 2020, the UNIPCC will have to face the scientific evidence.

Page 8 The last IPCC report overestimated the impact of aerosols. The net impact of greenhouse gases and aerosols rises from 1.72 W m-2 to 2.40 W m-2. Negative forcings dramatically fall. The positive forcing impact falls, despite the major contributor, CO2 rising from 1.66 W m-2 to 1.82 W m-2. The net impact of CO2 reduces from 100% to around 75% of warming impact. It is no longer possible to talk of “rising CO2″ as a shorthand for anthropogenically-caused rising greenhouse gases.

NB – the SPM file I refer to can be accessed below. Please compare my comments with the file.

SummaryForPolicymakers_WG1AR5-SPM_FOD_Final

Kevin Marshall

Cold water on sea level rise alarmism

The new article in Nature on “Recent contributions of glaciers and ice caps to sea level rise” (Jacob et al. 2012) is in stark contrast to what has gone before. It is far from the previous claims.

The main estimates before Jacob et al. 2012 were:-

  • The Himalayan Glaciers will disappear by 2035. (UNIPCC AR4 2007) Changed to the Himalayan Glaciers may disappear by 2350. (UNIPCC 2010)
  • The Grace Satellite data shows that the polar ice caps are not only melting, but the melt rate is accelerating. Velicogna 2009 claimed that the acceleration in Greenland was −30 ± 11 bnt/yr2 to 286 bnt/yr-1 in 2007 to 2009, and in Antarctica was −26 ± 14 bnt/yr2 to 246 bnt/yr-1 in 2007 to 2009. Concentrating on the period from 2006 to early 2009 for Antarctica only , Chen et al. 2009 estimated that the continent was losing ice at the rate of 190 ± 77 bnt/yr-1, two-thirds is of which comes from West Antarctica, covering about a quarter of the total land surface area. By 2010, the loss from both polar caps would, by Veligona’s estimate be 600 to 650 bnt/yr-1.
  • The average of these two articles was that in 2010 there would be around 600 bnt/yr-1 loss per year.
  • One of the articles’ authors, Prof John Wahr of University of Colarado, Boulder, had previously stated that the Grace measurements indicate an accelerating trend in Greenland. The current graph at Wahr’s website for Greenland shows a distinct accelerating trend through to the start of 2010.

    Mass variability summed over the entire Greenland Ice Sheet, monthly Gravity Recovery and Climate Experiment (GRACE) results (black line; the orange line is a smoothed version) April 2002 and December 2009.

    Prof John Wahl’s graph of Greenland Ice sheet loss, indicating a doubling of the rate of loss over the period to around 150 bnt/yr-1 in 2009.

  • In Zwally and Giovinetto 2011, using three separate estimation techniques, and including the pre-satellite data from 1992 to 2002, estimated the range of +27 to -40 bnt/yr-1.

The new paper in Nature:-

  • Estimates no net loss from the Himalayas in the period 2003 to 2010. When the claim that the Himalayas would lose their glaciers by 2035, Rajendra Pauchari, head of the UNIPCC said the doubts were “voodoo science”. Now even the more moderate claim of melting over hundreds of years looks to be in doubt. Josh has penned a cartoon to illustrate this point.

  • Velicogna 2009, seems somewhat extreme. The Nature paper would estimates a loss of 50% to 75% Velicogna estimate for 2010.
  • Most importantly, there is no mention of acceleration of ice melt from the polar ice caps. This sudden turn-around might be to a sudden change in the data. The sea level rise appears to have stalled in the last 18-24 months, so the sea ice melt (which the Nature paper estimates accounts for 40% of the sea level rise) may have stalled as well. (See Appendix 2). It is necessary to re-run the Nature paper numbers for 2011 data to confirm if this is the case.

In conclusion, it looks that the new nature paper reaches a more moderate position than previous papers using the GRACE satellite data, as it uses a longer period, and subjects the data to a more detailed breakdown. However, in terms of the polar ice melt, it still more extreme than a paper that uses a longer timeframe and three distinct methods of calculation.

Appendix 1 – Leo Hickman in the Guardian has a breakdown of the figures, that nicely puts the issue in context.

Glaciers
Ignore Region Rate (Gt yr-1)
1 Iceland -11.±.2
2 Svalbard -3.±.2
3 Franz Josef Land 0.±.2
4 Novaya Zemlya -4.±.2
5 Severnaya Zemlya -1.±.2
6 Siberia and Kamchatka 2.±.10
7 Altai 3.±.6
8 High Mountain Asia -4.±.20
8a Tianshan -5.±.6
8b Pamirs and Kunlun Shan -1.±.5
8c Himalaya and Karakoram -5.±.6
8d Tibet and Qilian Shan 7.±.7
9 Caucasus 1.±.3
10 Alps -2.±.3
11 Scandinavia 3.±.5
12 Alaska -46.±.7
13 Northwest America excl. Alaska 5.±.8
14 Baffin Island -33.±.5
15 Ellesmere, Axel Heiberg and Devon Islands -34.±.6
16 South America excl. Patagonia -6.±.12
17 Patagonia -23.±.9
18 New Zealand 2.±.3
19 Greenland ice sheet.+.PGICs -222.±.9
20 Antarctica ice sheet.+.PGICs -165.±.72
  Total -536.±.93
  GICs excl. Greenland and Antarctica PGICs -148.±.30
  Antarctica.+.Greenland ice sheet and PGICs -384.±.71
  Total contribution to SLR -1.48.±.0.26
  SLR due to GICs excl. Greenland and Antarctica PGICs -0.41.±.0.08
  SLR due to Antarctica.+.Greenland ice sheet and PGICs -1.06.±.0.19

 

Appendix 2 – University of Colarado Sea level Rise Estimates

Follow

Get every new post delivered to your Inbox.

Join 26 other followers