Discussion > GHG Theory step by step
Supertroll
Thank you for the link. The paper makes a good case that there are active volcanoes along the West Antarctic rift, and that they are probably Pleistocene, ie. no more than 2.5 million years ago. I had not realise that rifting was taking place along that coast.
I did note this paragraph.
We do not consider it likely that volca-
nism has played a significant role in triggering
the current retreat, for which there is compelling
evidence that the forcing has initiated from the mar-
gins (Turner et al. 2017),
That agrees with what I've been saying.
That agrees with what I've been saying.
Oct 3, 2017 at 11:44 PM | Entropic man
Yes, based on no evidence.
You quote Trenberth's Energy Budget, but no matter how small a fraction of 1 percent these volcanos are contributing, you still assume that only CO2 can upset Trenberth's Energy Budget, even though the Climate Science Computer Models that depend on Trenberth's Energy Budget have been proved to be overheating.
These volcanos (and more? plus other heat sources not included by Trenberth?) actually confirm that Trenberth's sums further overstated the amount of heat, that Climate Science still claims must be due to CO2.
If Trenberth's "Missing Heat" is actually Trenberth's Surplus Heat, then Climate Science is proving itself worse than predicted, and now confirmed by the inaccuracy of the models.
EM. That paragraph is based upon no evidence whatsoever. It's been added to get the paper through the AGW thought police. No one has any data upon heat flow rates but the paper does make a comparison with the East Africa Rift (where there are abundant measurements). It would be an interesting exercise to use the EAR heat-flow measurements in Antarctica and given the insulating properties of ice, calculate the heat buildup. Remembering that ice melts under pressure, any additional geothermal heat will be highly effective.
"there is compelling evidence that the forcing has initiated from the mar-
gins (Turner et al. 2017), That agrees with what I've been saying."
No it isn't. You've been rabbiting on about climate change, whereas I've been saying it's due to the Archipelago extending northwards into warmer currents (at the coasts) and geothermal heat. I've repeatedly challenged you to 1) demonstrate how in the Thwaites glacier area where the basal ice is melting away from the coast this could be a consequence of climate change, and 2) the source of your 1% figure for the maximum melting that could occur from volcanism. When are you going to deliver?
From the same skeptical science article:
https://www.skepticalscience.com/Kevin-Trenberth-travesty-cant-account-for-the-lack-of-warming.htm
"A subsequent study by Balmaseda, Trenberth, and Källén (2013) determined that over the past decade, approximately 30% of ocean warming has occurred in the deeper layers, below 700 meters. This conclusion goes a long way to resolving the 'missing heat' discrepancy. There is still some discrepancy remaining, which could be due to errors in the satellite measurements, the ocean heat content measurements, or both. But the discrepancy is now significantly smaller, and will be addressed in further detail in a follow-up paper by these scientists."
The possibility that Trenberth's Energy Budget might be wrong was not considered. Trenberth, along with Balmaseda and Kallen got more funding to prove Trenberth was right.
Would Climate Models be more accurate (generating less overheating) if Trenberth's sacred Energy Budget was subjected to "adjustments and homogenisation" to match reality, rather than trying to adjust and homogenise reality to match Trenberth?
This is a useful weather/climate prediction, based on data collected for Climate Science and their Models.
https://wattsupwiththat.com/2017/10/04/cooler-global-temperatures-ahead-indications-are-that-la-nina-is-returning/
The prediction is based on historic observations, and there does not seem to be an attempt to blame a particular cause. These predictions tend to be accurate, and this one is not helpful for Climate Scientists or their failing Models.
…approximately 30% of ocean warming has occurred in the deeper layers, below 700 meters.Based on what evidence? As the oceans average about 2 kilometres in depth, they are suggesting that they have evidence on the most unmeasured half of the oceans; probably a few thousand measurements of over 0.7 BILLION cubic kilometres of water over an unspecified time – and, what is the “heat gain” claimed? 0.1K? Or less? In other words, an unmeasurable increase claimed for an unmeasured volume… and they call it science!
.... and they call it science!
Oct 4, 2017 at 9:19 PM | Radical Rodent
The article was written by one of The Guardian's experts, Dana Nuccitelli. Sometimes it is difficult to distinguish between the output of The Guardian and Skeptical Science, they must have similar sources/funding.
Is it possible that Green House Gas Theory is based on valid (but insignificant) science, however the cumulative effect of exaggerated assumptions and numbers being rounded-up, have been compounded with excess interest, into mass hysteria?
Climate Scientists continue to maintain their science is correct, whilst nothing out of the ordinary continues to happen. Climate Science still can't explain Global Warming and Cooling since the end of the last ice age, which they can't explain either.
I am sure the effects of these events should have received more media and scientific attention (apart from the travel chaos) but no one knows how to spell or pronounce it. From Wikipedia:
"The volcanic events at Eyjafjallajökull in Iceland which, although relatively small for volcanic eruptions, caused enormous disruption to air travel across western and northern Europe over an initial period of six days in April 2010. Additional localised disruption continued into May 2010. The eruption was declared officially over in October 2010, when snow on the glacier did not melt. From 14–20 April, ash from the volcanic eruption covered large areas of northern Europe. About 20 countries closed their airspace to commercial jet traffic and it affected about 10 million travellers.[1]"
Did the ash cloud cause any extra melting of snow/ice/permafrost, or any detectable effect on weather/climate etc, or was it lucky that the eruptions did not happen earlier in the year?
A very different view of the cyclical nature of Arctic Ice extent from Norway
https://wattsupwiththat.com/2017/10/05/arctic-ice-natural-variability/
It actually contains predictions based on past performance.
Supertroll
" It's been added to get the paper through the AGW thought police."
I can't believe I'm trying to have a sensible scientific debate with a man who thinks like that.
Oh yes, I have your numbers.
Schroeder at al(2014) measured geothermal heat flow data for Thwaites. Low values 114mW/M^2, high values 200mW/M^2.
Based on those minimum and maximum values, over the 180,000 sq km of Thwaites that melts between 0.1 and 0.18 cubic kilometres of ice per year.
Rignot(2001) Table 4 measured a negative mass balance for Thwaites of -17cubic km per year.
0.1cubic km of geothermal melt is 0.58% of the net melting. The worst case 0.18 cubic km is 1.05%.
EM. Concerning your 9.12 pm post first. I repeat the paragraph in question is based upon no evidence given in the paper and concerns a topic that was not the subject of the research done. Clearly, however, by incorporating the paragraph the authors ensure that their paper does not run foul of any potential obstructionist reviewer who might get the idea that the whole paper was a fossil-fuel sponsored attempt to deny the dogma of climate change as the only explanation of Antarctic deglaciation and sea level rise. After all researchers are well known for shoehorning climate change into proposals to get them funded, why shouldn't they shoehorn a placatory paragraph into the final product to ensure a speedy acceptance?
Calling potential obstructionist reviewers climate thought police was just my feeble attempt at humour, which Ravishing Rattie repeatedly tells me I should avoid.
EM. You wrote "Schroeder at al(2014) measured geothermal heat flow data for Thwaites. Low values 114mW/M^2, high values 200mW/M^2"
1. Perhaps you should read more carefully. The actual values are "The minimum average inferred flux is ∼114 ± 10 mW/m2. High-flux areas exceed 200 mW/m2."
2. These values have not been measured, they are based on a model of the geothermal heat flux based upon the distribution of strong radar reflections (inferred to be indications of subglacial water) and yet another model of water flow.
3. Despite reading the extended abstract severaI times I fail to see where or how the geothermal heat flow is calculated. However, it must be true that the higher the heat flow, the greater the amount of subglacial water created and the faster the glacial ice will flow to the sea, there to melt.
4. Throughout the authors stress the importance of geothermal heat to changes to the dynamics of the glacier, it controlling the seaward flow rates and therefore the losses in ice volume.
The model of Thwaites Glacier ice loss is geothermal heat melts basal ice creating water that lubricates the glacier floor. The glacier flows down to the sea at faster rates. If the seaward loss is not matched by surface accumulation, then the glacier thins. Nothing to do with surface melting or climate change. Changes in geothermal flux cause significant changes in glacial dynamics.
BTW the situation is much more complex. Thinning ice reduces bottom pressures inhibiting ice formation. Migrating ice is the result of internal shearing which generates frictional heat. I wonder if their model incorporates all the variables?
Correction. Sentence in last paragraph should read
"Thinning ice reduces bottom pressures inhibiting WATER formation".
Supertroll & EM from the PNAS
"We estimate a minimum average geothermal flux value of about 114 mW/m2 with a notional uncertainty of about 10 mW/m2 for the Thwaites Glacier catchment with areas exceeding 200 mW/m2 (Fig. 3). These values are likely underestimates due to the low uniform geothermal flux value used in the ice sheet model"
At least they admit that they are estimates, with specified uncertainty, fed into models of unknown accuracy, to produce an answer of benefit to the climate science models that we now know that even Climate Science admits are overheating.
"Schroeder at al(2014) measured geothermal heat flow data for Thwaites" (Entropic Man) does seem a slight over exaggeration of the Scientific methodology, and Schroeder includes appropriate caveats.
Supertroll
Schroeder at al did the heat flow determination.
I calculated the amount of melt due to that heat flow myself, repeating a calculation from an earlier discussion.
You blame the thinning onf the glacier on increased basal heat flow. Schroeder at al said nothing about changes in heat flow. Do you have more data? Do other rift systems show fluctuations in heat flow over time?
Here's an interesting contribution for those who find it difficult to visualise how the greenhouse effect affects energy flow.
Read the paper EM, its the authors that attribute thinning to increased ice flow rates that exceed accumulation rates.
Magma chambers are always filling, emptying and moving around. When they discharge, sometimes causing volcanic eruptions, heatflow rates increase significantly.
Here's an interesting contribution for those who find it difficult to visualise how the greenhouse effect affects energy flow.
Oct 6, 2017 at 7:45 PM | Entropic man
Did you visualise his mistake?
EliRabett said...Wm, the point is to have something in big print and simple figures that can be pointed to in a tweet. Understanding from those with an agenda is not hoped for. Stopping them from confusing the crowd might be6/10/17 8:11 AM
John Garland said...It's pretty terrible that a lowly psych stats person has to correct your math. Hopefully your colleagues never find out! :-)6/10/17 9:09 AM
EliRabett said...Eli was never into proofreading.
Why is it Climate Models don't work????????
A further example of Climate Scientists favouring the work that supports their own cause:
https://wattsupwiththat.com/2017/10/07/the-incestuous-nature-of-the-ipcc-reports/
Meanwhile, a post making an "observation", without attribution:
https://wattsupwiththat.com/2017/10/08/weak-solar-cycle-continues-the-sun-is-spotless-again/
Supertroll
"its the authors that attribute thinning to increased ice flow rates that exceed accumulation rates. "
Other workers have shown that. There are a number of papers reporting how the glacier has thinned, increased its flow rate and lost mass over the period since Rignot's 2001 paper. There are also three three processes observed which affect melting. These are geothermal heating, surface melting and warmwater basal melting of the floating tongue.
Schroeder at al speculate that the primary cause is geothermal heating. The problem is that they only give one set of data, so their suggestion that the increased mass loss is due to increased geothermal heating is pure speculation.
Without data on wheter and how much the geothermal heat flow has changed they have no way of knowing if, and to what extent, it has contributed to the negative mass balance.
You were in the trade. Do you have data?
EM. Are you sure? I doubt if any of the three inferred methods of glacial thinning you mention have been OBSERVED. However a link between faster flow rates and thinning has been deduced. Unless you have another explanation for the increased flow rates than increased lubrication caused by subglacial water produced by geothermal heat fluctuations (which undoubtedly do occur) then accept the most likely interpretation. Unless you are so besotted by tying everything to global warming that you wilfully ignore the most obvious.
Supertroll
Here is evidence that the flow rate of the Thwaites glacier is not strongly coupled to the amount of water between it and the rock beneath.
Subglacial lakes drained and added 16 cubic kilometres (20km ×40km by 20m) of extra water lubrication without producing much change in the ice flow rate. That is the equivalent of 88 years of geothermal melting at the 0.18 cu km/year that I calculated from Schroeder at al. If you can dump that much water into the system without a significant response then any increase in geothermal heating is not likely to have much effect. Your hypothesis fails.
Supertroll, golf charlie
This is the effect of warm water on melting behaviour of Antarctic glacier tongues. .
Note that this has been directly observed. An ROV mapped temperature and salinity and observed both erosion channels in the sea floor from the inflow and erosion channels on the underside of the ice from the outflow. Outward flow rates at the ice edge have increased since the previous visit.
From skeptical science
https://www.skepticalscience.com/Kevin-Trenberth-travesty-cant-account-for-the-lack-of-warming.htm
"Trenberth states unequivocally that our planet is continually heating due to increasing carbon dioxide. This energy imbalance was very small 40 years ago but has steadily increased to around 0.9 W/m2 over the 2000 to 2005 period, as observed by satellites. Preliminary satellite data indicates the energy imbalance has continued to increase from 2006 to 2008. The net result is that the planet is continuously accumulating heat. Global warming is still happening."