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billovitch at 17:55 PM on 1 November 2014New research quantifies what's causing sea level to rise
Good post, John
There is a third possible contribution to sea level rise: the increase in human extraction of groundwater, which then makes its way to the oceans.Do the authors mention this at all?
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Ashton at 16:07 PM on 1 November 2014Republican politicians aren't climate scientists or responsible leaders
Leto I agree with you that we will never reach common ground and that political debate is not the core business of SkS despite climate change being mired in politics world wide. It appears however that Ken of Oz, who introduced this particular political aspect, is of a different opinion. Perhaps you and Ken of Oz might read Paul Kelly's piece on the status which gives a more measured assessment of climate policy in Australia than do many other pieces. (http://tinyurl.com/o7b4ecz)
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sidd at 14:14 PM on 1 November 2014Antarctica is gaining ice
One paper from 2007 that mentions the effect is Hansen(2007) in Phil. Trans. Roy. Soc doi:10.1098/rsta.2007.2052 (specifically Fig 3, discussion thereof.)sidd
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sidd at 13:50 PM on 1 November 2014Antarctica is gaining ice
Dr. Steel is correct, there is an effect but it is well known. A recent paper that pointed out the importance of orbitally driven change in NHemis. spring insolation coupled with albedo flip from ice melt driving deglaciation over the last 4 stades was by Hansen, but I do not immediately recall the reference.sidd
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Tom Dayton at 13:37 PM on 1 November 2014Antarctica is gaining ice
Duncan Steel, how does your proposed mechanism account for stratospheric cooling, please?
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Tom Curtis at 11:46 AM on 1 November 2014Antarctica is gaining ice
duncansteel @305 Cont.
TC: "Berger (1978), from whom he draws his algorithms"
DS: "False statement. I did not draw my algorithms from Berger's wonderful papers. I derived the algorithms from first principles. It was only after the fact, when I saw what my results must imply, that I turned to Berger's FORTRAN program to do check calculations, as I have described in some detail. It is noteworthy that, as I discuss in my essay, essentially the only parameters needed in order to derive a good-enough calculation of the insolation changes are the lengths of the mean tropical year and the anomalistic year. The difference between those indicates the circa 58 years it takes perihelion to shift by one day closer to the vernal equinox. The use of the changing orbital eccentricity and obliquity of the ecliptic is nice, for completeness, but over only a century or two those slowly-altering values have little effect. Just the comparative values of the two year lengths are all that is required, to first-order."
(My emphasis)
First, sorry for my mistaken impression of your reliance on Berger.
Second, I wish I had twigged to the significance of the section on anomalistic and tropical years in your blog post a little earlier. While I had read it, I had not noted its significance. However, yesterday, I realized the possibility and set up the calculations in a spread sheet. On that basis I accept that there has been a drift of the equinox relative to the perihelion of approximately 4.3 days over the last 250 years, and 17.3 days over the last 1000 years. That drift has been to a very close approximation, linear with time. Further, the change in average spring insolation has also been linear over time to a close approximation:
The change in Autumn insolation has been also very nearly linear, and opposite in sign, while those of summer and winter have a detectable curve, but are opposite in sign and neglibible relative to the changes in spring and autumn.Based on this, I withdraw any suggestion that you may have made an error in your calculations of the orbital effects. I do not accept that climate scientists have made the mistake you attribute to them. Climate models do not in general, simply look up Berger's table of values, but independently calculate insolation based on orbital mechanics. To show that they have made an error, you would need to show the error in the code.
Returning to the linear change shown, here are temperature reconstructions for the Northern Hemisphere over the last two thousand years:
And for the entire Earth:
Here are sea levels for the last 3000 years:
Ninety percent of the total increase in heat content at the Earth's surface goes into the oceans, so that any significant increase in that heat content should be reflected in rising sea levels due to thermal expansion in addition to ice melt.
And speaking of ice melt:
No measure of historical temperatures or proxies of heat content show the linear increase over the last thousand, or the last 250 years that is required by your theory. So, even allowing my error in criticizing you on the orbital mechanics, your theory stands refuted by empirical evidence. (As I said before, this is the crux of the issue.)
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duncansteel at 11:45 AM on 1 November 2014Antarctica is gaining ice
It is time for me to take my leave from this website. Sorry to have disturbed your arguments.
I have been bemused by various things I have seen here. For example, Mr Curtis (in #299) sits in judgement and states with regard to my work that it is: "an example of pseudo-science, not science." Within 48 hours he is writing (#309): "It is the editor and peer reviewers of a suitable journal who will be far more able to pick up any errors in your assumptions or calculations than I. " That is, he feels able to make unwarranted and unjustified criticisms at one stage, but when challenged pleads a lack of competence to have made such criticisms in the first place.
As the saying goes, democracy is a wonderful thing apart from that bit about any old yokel getting a vote. The same applies to the internet. Anyone reading this website is mostly reading garbage. It is clear that the motivation of many participants is simply arguing and chest-beating, not any search for scientific truth.
Time for a moment of honesty. Who amongst the readers out there can honestly say that they knew how apsidal precession is causing the lengths and the natures of the seasons to change? Here is the plot that appeared in my 'essay':
So, who knew that winter is getting shorter? And also it is getting milder, because during winter the Earth is closer to the Sun now than it was 250 years ago? And who knew that the same applies to spring, because throughout the first half of the year our planet is closer to the Sun than it was 100 or 250 years ago? And where does this information appear in any IPCC report? It is obvious that such an astronomical effect must be causing some climate change, so why is it missing from the IPCC reports?
If you look at any of the posts about the missing Malaysian airliner on my website, you will find that generally I am a person who favours cock-up theories over conspiracy theories. This is a cock-up: climate scientists have made a grievous error in their analysis of how the insolation reaching different latitudes at different times of year is varying across the decades and centuries, and so have missed the effect I term CSI.
In leaving you, here are my own views at present:
-Yes, the global mean temperature has increased over the past century or so.
-Yes, there appear to be various changes in the climate occurring.
-Yes, the increase in so-called 'greenhouse gases' since 1750 is responsible in part (of course!).
-No, AGW is not the only agency causing the changes: there appears to be a natural effect (CSI) which has been ignored or neglected or not recognised previously.
That set of views I hold now in the light of such information and facts as are available. As the available information and understandings alter, I may well change my views. What do you do, when new information becomes available to you? From what I have seen on this site so far, mostly you shout, scream, and hurl abuse.
Yesterday evening I was walking down the street when some delirious drunk yelled at me the opinion that I was a "black bastard." Now, I am neither of those things, although I would not regard either term as being an attack on my basic character, which is far more important than my skin colour or parentage. However, I chose not to engage him in any debate on the matter, for obvious reasons.
The reason I am leaving this webpage/blog after a brief foray is similar.
The method employed I would gladly explain,
While I have it so clear in my head,
If I had but the time and you had but the brain—
But much yet remains to be said.Lewis Carroll, The Hunting of the Snark.
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duncansteel at 10:51 AM on 1 November 2014Antarctica is gaining ice
Ref #322:
"What he does not do, and should have done is plotted the change in the effect over time against some emperical measure of either temperature or surface heat content"
It is not for you or anyone else to tell me what I should have done.
Equally well it is not for me to tell you how you should spell various words (such as empirical, propaganda, and several others).
What you are describing is what you would like to see done, so as to elucidate matters. I agree. All I have done - and it has taken me two years of work, it now being 16 years* since I realised what was going on - is to flag to anyone interested a physical effect which I believe will be causing climate change to some extent. Others can pick up the ball and run with it, including yourself, if they so desire.
*I first indicated the significance of this effect in pp.358-362 in my book Marking Time (Wiley, NY, 2000), which I completed writing late in 1998.
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duncansteel at 10:42 AM on 1 November 2014Antarctica is gaining ice
Ref #319: Yes, you are a slow reader. I previously pointed out here (#305) that one might seize on the distinction between the surface area and the cross-sectional area of the Earth as a complaint.
None of this is important. As I made clear in my 'essay', my reason for comparing the natural changing insolation values (in W/m2) against the IPCC net AGW figures (the AGW 'forcing') is simply this: is the insolation change significant, or is it a value only one part in a million of the IPC AGW value? The answer is: it (natural changing insolation value) is of the same order as the AGW value, and therefore it is significant and cannot be ignored. Hitherto it does not appear in the IPCC reports, and so it has been ignored, or neglected. (It is also true that all papers I have examined which consider the changing insolation due to apsidal precession have been wrong - so much for peer-review - because they have made erroneous calculations based on Berger's correct insolation values.) The IPCC reports document the plausible intrinsic solar output increase of perhaps 0.12 W/m2 since 1750 as being the only significant natural agency in terms of climate change: if my calculations of the natural changing insolation values are correct, then the IPCC is demonstrated to have erred in that respect.
Those who like to call me "arrogant" might care to note that I preface essentially all statements regarding my own work with a qualifying term such as "unless I have made an error" or "if I am correct". It behoves anyone and everyone to have some humility in the face of complex matters. Note also that I have appealed to all to inform me of any publications, anywhere, in which the same sorts of insolation change calculations as I have performed are described; that is, I am admitting ignorance of any such work having been done, and asking for help. As of yet no-one has pointed me towards any such publications.
In any case you, like all others here it seems, are still misunderstanding the crux of the CSI hypothesis. It's not the magnitude of the changing insolation that is important: it's when and where it occurs! The small changes in insolation will cause earlier and more extensive spring melting of Arctic ice, and indeed less ice formation over winter because northern winters are now shorter and milder than they were in 1750, due to apsidal precession. If you have a square metre of snow (albedo circa 0.9) receiving insolation of 500 W/m2, the absorption rate is 50 W; once that snow is gone, exposing (say) wet soil beneath (albedo circa 0.1) the absorption rate goes up to 450 W on that square metre, nine times that previously. Thus, to assess the actual magitude of the CSI effect will require a large amount of work and debate and discussion, far more than I can possibly do myself. My intent is solely to flag the issue, and let others take over.
To develop an understanding of how the CSI affects the climate will require the development of new models (evolved from the present GCM efforts) incorporating gradual changes in insolation and ice and snow coverage and following the various influences on the climate over many annual cycles. So climate scientists are not going to be put out of work.
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duncansteel at 10:15 AM on 1 November 2014Antarctica is gaining ice
Ref #321: "Ah, I see. You don't like your peers scrutinizing your work. Good to know." - Do you not realise that when you write something like that, anyone else with the wit can quickly see that you do not (have much wit)? As I have already stated, my work has already been scrutinized by my peers, and no substantive errors have been found. These include, shall we say, fairly senior people (e.g. the person who is nominally the top astronomer in the realm of HM Queen Elizabeth, if you have the wit to get my meaning).
By publishing things on the web I make them available for scrutiny by anyone and everyone, not just those who have access to journals (which can be expensive to obtain).
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duncansteel at 10:09 AM on 1 November 2014Antarctica is gaining ice
Ref #317: karly, thanks again. I worked in just such departments for some years. I found few people really interested in science, only people interested in self-advancement, and the best way to gain that was bring in money and hence gain power. To the contrary, I am interested in science, and have spent a good fraction of my time doing (and publishing, in peer-reviewed journals!) scientific research with zero funding for the past 18 years (i.e. since I last had research funding; I had plenty before that).
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Ken in Oz at 10:06 AM on 1 November 2014Republican politicians aren't climate scientists or responsible leaders
Ashton, I think you are missing the point; PM Abbott finds it expedient to keep alive a thin pretense of treating climate like it matters - because the majority of Australians do think it matters. He and his team assiduously avoid stating they have a goal of eliminating climate as a policy consideration and "Direct Action" fits the bill as an interim measure that looks the part but fails to embody any clear commitment to transition to a low emissions economy. By not overtly stating their anti-climate action goals the Abbott government avoids debating it and it can take climate policy backwards with less fuss, even if it is not - yet - able to achieve a complete elimination.
This is a government that has sought to eliminate the Climate Change Authority, the Clean Energy Finance Corporation, Carbon pricing, energy subsidies to renewables based on emission reductions goals and the Renewable Energy Target. It routinely promotes the benefits of long term use of fossil fuels with deliberate disregard for climate consequences. It's chief business advisor is a declared climate science denier, as was the head of the review (unfavorable of course) of the Renewable Energy Target. It has greatly reduced funding for Australian Science. At no point have I heard any senior figure in the Abbott government express strong commitment to climate action since taking office, nor express clear acceptance that the science is valid or that there really is a serious climate problem - any that isn't qualified into irrelevance or contradicted in the same breath. On the contrary, their utterances are filled with hints and suggestions that they reject climate science and they routinely downplay or ridicule expectations of damaging climate consequences like greater bushfire danger or heatwaves or changes to precipitation patterns. Doing the least possible is held as a virtue. At no point is emissions reduction put forward as anything but the maintaining of a prior commitment their party had made, one that does not extend beyond 2020. Even the goal of 5 to 15% reductions is reduced to 5% in all discussion.
It's apparent that behind the vague and condradictory utterances lies a conviction that global efforts to restrain emissions will collapse and underpinning that is embedded miscomprehension of climate science that allows them to sustain their belief that it's a non-problem, blown out of all proportion. But it remains useful to pretend otherwise for broader public consumption.
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duncansteel at 10:06 AM on 1 November 2014Antarctica is gaining ice
Ref #318: " Any research-oriented academic for whom getting grants rather than perfoming the research is their primary aim has rather lost their way."
Yes, that is a fair summary of the situation, especially in climate science. It's called the buffalo syndrome. One buffalo finds a new, juicy green patch of grass, and soon the rest of the herd joins him/her. But they've all got their heads down, chewing away, and none look to see if there is something better to be had: until a buffalo with heterodox views comes along.
"The reason we publish papers is so that other scientists can take what we have done and build on it (as we ourselves build on the work of others). Grants are a means to an end, not the end itself." - Ah, I was young and naive once, too.
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duncansteel at 10:01 AM on 1 November 2014Antarctica is gaining ice
Ref #316:
"The point really is, that publish on a website and you are just another crank blog-scientist. Publish in a peer-reviewed journal and other scientists take notice and do something with it. Not a single climate paper will change unless you do."
That it will take others some time to understand what I have done and catch up is not a concern to me. Read Thomas Kuhn sometime. Twenty-five years ago most people thought I was a crank for arguing that we should take the hazard posed by asteroids and comets seriously; now they are the focus of NASA's future manned and robotic space missions, at Obama's behest. At the time (25 years ago) it was a fight to get anything on that topic into the journals, because they had their favoured topics. The same applies now in terms of climate change.
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Tom Curtis at 08:40 AM on 1 November 2014Antarctica is gaining ice
MA Rodger @319, DS calculates the insolation by day and by latitude rather than using a global average. Later in the blog post he calculates what he purports to be the effect after adjustement for albedo. Therefore he correctly uses the TSI rather than the globally averaged and albedo adjusted effect in calculating initial ratios of adjustment. What he does not do, and should have done is plotted the change in the effect over time against some emperical measure of either temperature or surface heat content (either OHC directly for when we have the data, or glacial extents, or sea levels).
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Leto at 08:36 AM on 1 November 2014Republican politicians aren't climate scientists or responsible leaders
Ashton,
The relevant constraint on possibility, in this context, is not physical or legal but political. Not having a policy at all would only be possible in a sense too trivial to discuss; it would not be politically viable because there are still some Australians who respect the science, and for the moment they still have the vote, and TA needs at least some of the centre to vote for him to remain politically viable. That means he has to do just enough to make his inaction on climate change debateable at the margins. He has already pushed climate change denialism and inaction about as far as he can go without self-combusting in a fiery ball of farce. If TA announced a 4% reducton target, for instance, he would be at serious risk of looking like a parody of himself.
I agree with Donny that this thread topic invites political comment, but I also agree that political debates are futile and not core SkS business. We clearly have zero chance of reaching common ground, so let's leave it at that.
Leto.
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Rob Honeycutt at 07:37 AM on 1 November 2014Antarctica is gaining ice
Duncansteel... "On my own website I can publish what I like, and what I believe to be correct, without being forced by referees with vested interests to alter what I want to say."
Ah, I see. You don't like your peers scrutinizing your work. Good to know.
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karly at 05:58 AM on 1 November 2014Antarctica is gaining ice
@318 A great ideal. However, if you talk to any non-tenured academic, you will find that getting money, so they remain employed, is top of their list of priorities.
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ajki at 05:48 AM on 1 November 2014What 1970s science said about global cooling
Kevinb3@21
"I've read quite a bit from this website. I'm not coinvinced of the veracity of the site; this could be remedied if a bibliography were published for each reference and a passage from these reports or abstract."
This is underestimating the resources of this platform by a great margin.
For example within the left margin are some buttons to click - one of these is labeled "History of Climate Science". Anybody checking this part of SkS will have to have enourmous time to spend on reading. Advance the timeline to 1972 and click on the year dots and then look down to the section below the graph - you'll see links there (in abundance).
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MA Rodger at 03:33 AM on 1 November 2014Antarctica is gaining ice
Re:- The Changing Spring Insolation Theory (CSI).
Well I'm a very slow reader so I'm still only halfaway down the first page of Duncan Steel's explanation. Thankfully there appears to be only one page.
If CSI is to be considered seriously, the strength of the effect requires stating correctly. So when the explanation says:-
"The flux of sunlight at Earth being about 1,360 W/m^2, the above figures of 1.6 and 2.29 are respectively equivalent to 0.12 per cent and 0.17 per cent of the solar flux."
there is a problem, Houston. The measure of insolation is for the projected 'discal' value, the figures for central average values for AGW RF estimated by AR4 & AR5 are for the spherical 'global' value acting over 4x the area. Also with a third of insolation bouncing off into space, the value of the forcing resulting from changing insolation is reduced further. Thus the comparative AR4/AR5 values are 6x bigger than stated - 0.72% & 1.0%.
Looking ahead, down the page at the tabulated Langleys, the error does not appear to have spread so far.
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Stephen Baines at 03:07 AM on 1 November 2014What 1970s science said about global cooling
Kevinb3...the bibliography you seek is in the paper that the OP describes and to which it links, twice. All you need to do is follow the link.
You state cherry picking is common on the site, but provide no concerete examples, so that critcism is empty innuendo. If you want a proper discussion, talk about a specific examples and make a case.
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ZincKidd at 02:29 AM on 1 November 2014New research quantifies what's causing sea level to rise
Needs proofreading— "reason" & "region" are swapped in a couple of instances...
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Kevinb3 at 02:28 AM on 1 November 2014What 1970s science said about global cooling
I've read quite a bit from this website. I'm not coinvinced of the veracity of the site; this could be remedied if a bibliography were published for each reference and a passage from these reports or abstract. In similar fashion to the way you provided the context in this article "The Science Isn't Settled, quoted a 1972 National Science Board report as follows"; Overall it's sketchy with the emphasis supporting AGW.
If, as you say, you found very few papers (7 in total) that predict global cooling but found more papers (42 in total) that predict global warming in the 1970's, then you obviously have already done some homework; so it shouldn't be too exhausting or a strecth to back up your claims by posting the necessary links, bibliography etc., for EACH of these papers instead of cherry picking select data. This is common on your site. To say there were 42 papers on AGW published in 1970's sounds impressive, but...
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Satellites show no warming in the troposphere
knauble - Here's the same graph along with trends, and you can clearly see that the 60-month single point offset Spencer/Christy used results in the UAH trend sharing no common period with HadCRUT4 whatsoever.
If trends don't cross in the baseline period, you cannot reasonably judge any divergence - this is a clear error on their part. And quite deceptive when their claim is that similarly baselined models are running too high - as they've artificially introduced an offset.
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Satellites show no warming in the troposphere
knaugle - The reason for starting in 1982 was the 60-month averaging Spencer used, which leads directly to some of the distortions in the graphing. The satellite temps are more sensitive (higher swings) to ENSO and yearly variation than the surface temperatures, and the 5-year average for 1982 (1979-1984) is one of the highest peaks above trend for the UAH record.
'Baselining' to a single point of the 60-month average, as Spencer did, gives an artificial negative offset to the UAH record, as below:
Blue: HadCRUT4 60 month average, Red: UAH 60 month average baselined to the common average 1980-1999, and Green: UAH using Spencers 60-month average and a single point (mis)alignment.
As you can clearly see, the 60-month UAH alignment shifts the entire record down, artificially offsetting the satellite temps and making surface and model temperatures seem much higher. When in reality UAH swings both above and below the surface temps, as per the graphs baselined for comparison over a period longer than their internal variability.
I don't know whether Drs Spencer and Christy did this alignment out of an error of confirmation bias or as a deliberate 'trick', but either way the graphs they presented with that 60-month baselining are deceptive.
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Ashton at 23:52 PM on 31 October 2014Republican politicians aren't climate scientists or responsible leaders
You appear not to know that since the repeal of the emissions trading scheme Australia has had no official policy on climate. None at all. If the government is, as you and Ken of Oz appear to believe, eliminating climate as a policy consideration "as far as possible" why did it negotiate passage in the Senate of its policy of direct action? Surely by your and Ken of Oz's logic, not having a policy at all would have very effectively totally eliminated climate as a policy consideration. That the government did not stay with that situation clearly shows it is not eliminating climate as a policy consideration as far as possible.
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knaugle at 22:40 PM on 31 October 2014Satellites show no warming in the troposphere
The question WHY the trend line was from 1982 to ~2009 intrigues me because it is said that climatology deals in 30 year intervals or more. So 1979 to 2009 would be a "better" line. But it looks like the chart would show nearly the same result.
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Leto at 22:10 PM on 31 October 2014Republican politicians aren't climate scientists or responsible leaders
Ken in Oz wrote: "...climate as a policy consideration must be eliminated as far as possible from government business"
Ashton @63,
Note the "as far as possible". I think Ken in Oz has summarised the Australian situation rather accurately.
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Dikran Marsupial at 22:05 PM on 31 October 2014Antarctica is gaining ice
Karly, academic get grants in order to perform research and publish papers. Any research-oriented academic for whom getting grants rather than perfoming the research is their primary aim has rather lost their way.
The reason we publish papers is so that other scientists can take what we have done and build on it (as we ourselves build on the work of others). Grants are a means to an end, not the end itself.
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Ashton at 20:54 PM on 31 October 2014Republican politicians aren't climate scientists or responsible leaders
Ken of Oz
On this site much is made, and correctly so, of the accuracy of comments. Your comments about Australia’s PM are not accurate. His government is putting in place a direct action plan with the stated aim of reducing Australia's emissions to 5% below 2000 levels by 2020. This legislation has just passed through the Senate.
You may not like the policy and may believe it will not work or that it is too expensive or not as good as an ETS or whatever else. It is however inaccurate to state "that climate as a policy consideration must be eliminated as far as possible from government business - like Australia's Prime Minister is doing - hinting at but never clearly articulating that belief or goal. Like Australia's Prime Minister did”.
The actions of this government clearly refute that statement. Further relevant information, that further refutes your statement, about Australia’s planning for lowering CO2 emissions is at http://tinyurl.com/oyofe57
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karly at 19:40 PM on 31 October 2014Antarctica is gaining ice
"We only publish papers to get grant money? That pretty much news to my department"
I wonder where you are, because it's not news to any science-related department in any Australian University.
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scaddenp at 17:32 PM on 31 October 2014Antarctica is gaining ice
"On my own website I can publish what I like, and what I believe to be correct, without being forced by referees with vested interests to alter what I want to say."
We only publish papers to get grant money? That pretty much news to my department. The point really is, that publish on a website and you are just another crank blog-scientist. Publish in a peer-reviewed journal and other scientists take notice and do something with it. Not a single climate paper will change unless you do.
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duncansteel at 15:57 PM on 31 October 2014Antarctica is gaining ice
Response to #309, point (5)
"From this, and other related passages, I formed the idea that the effect DS describes is a function of the precession of the perihelion (relative to the vernal equinox)."
Of course it is: I have stated that rather clearly many times. You could google my paper entitled "Perihelion precession, polar ice and global warming" (although it is linked in my essay: footnotes 5 and 7).
"Of course, DS can (and should already have) calculated the change in insolation at the northern spring equinox over the last thousand (or two thousand) years, and plotted it against changes in temperature over the same period. Such a plot would largely resolve this issue one way or another."
Entirely incorrect, and demonstrates a lack of understanding of the physics involved. Yes, I have calculated such things as you mention in your first clauses, but that is not relevant. 'Temperature' is not 'Heat': a cubic metre of space near Earth's orbit has a 'temperature' (as defined by the particle speeds) of some millions of degrees, but an astronaut would freeze to death without a proper thermal stabilisation system (vide the Apollo 13 movie!) - this is because the heat content of a cubic metre of space is extremely low, and is dominated by the photons passing through it.
Suitable models to be used in the investigation of the effect of the changing insolation (in terms of DOY and latitude) over timescales of decades to centuries will need to encompass how much energy (i.e. heat) is being absorbed and how that energy is then re-distributed, and the models will need to be evolutionary/dynamical. That is, they will need to be set up to indicate how year-on-year changes occur in response to year-on-year insolation changes. A little more insolation one year means a little more ice melting means a little more sunlight being absorbed means a little less ice forming over winter means a little less to melt next spring, and so on; and also the contrary in other locations.
Fundamentally, this is indeed what Milankovitch was writing about in the 1920s and 1940s, when he identified latitude 65N as being pivotal. The problem is that people have falsely imagined that the orbital changes he was discussing only have effects over timescales of several millennia, at least. This is incorrect. Perihelion shifts by one day every 57 or 58 years: a typical human lifetime. The effect of that shift, I have shown, should not be ignored in climate change modelling, as it has been: in part because climatologists have made a rather basic astronomical error.
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duncansteel at 15:36 PM on 31 October 2014Antarctica is gaining ice
Response to #309 point (4)
"Perhaps you have difficulty recognizing sarcasm."
In all these things, please keep the debate on the facts, rather than any personal statements. The best way to reach the truth is to leave one's ego in the closet.
"In virtue of the fact that the total insolation is effectively unchanging, the net effect on the Earth's energy balance over the full year is also likely to be effectively unchanging (on which more later)."
That statement is obviously untrue, and many trivial examples could be given in order to disprove it. For example: if I hold my hand in direct sunlight, it will get warm due to the insolation. If I now hold a magnifying glass between my hand and the sun, the overall insolation reaching my hand may remain much the same, but its effect will be somewhat different.
The overall effect on the climate of the insolation will depend on when and where the sunlight arrives. As I have pointed out in the 'essay', what has happened (in an accelerating manner since 1246 CE) is that the insolation reaching far northern latitudes has increased during the first half of each year, and this should be anticipated to cause earlier and more-extensive spring melting of snow and ice, and therefore a progressively-earlier albedo reduction, and therefore more sunlight subsequently being absorbed across spring and summer: the ice albedo feedback effect acting positively (causing warming). For precisely the same core reason (apsidal precession) the opposite occurs in the southern hemisphere: less insolation at far southern latitudes, sea ice melting delayed, albedo increasing, less energy absorbed: growing sea ice: the ice albedo feedback effect acting negatively.
And if you look at my graphics carefully you will also see that there is an insolation increase at the furthest southern latitudes across austral summer, in accord with the observation of melting continental Antarctic ice.
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duncansteel at 15:25 PM on 31 October 2014Antarctica is gaining ice
Response to #309 point (3)
Again, your comments are entirely wrong. I picked the vernal equinox as a suitable point at which to illustrate the magnitude of the (positive) change, because it is the traditional start of the year; and it is the actual start of the year, for a science-based system (i.e. it's the point at which the ecliptic longitude of the Earth is zero). In fact, it is not the juncture at which the maximum positive insolation change (to the whole Earth) occurs. Anyone can look at that graph, or the one for the 1750-2000 changes, and estimate the relative magnitudes and the signs of the changes at different times of year.
Yes, of course the net effect (i.e. the summed change in insolation) is very near to zero. In my essay I noted that the overall/net change is very small, and really is just non-zero only due to two effects: (a) The orbital eccentricity alters very slightly; and (b) The Earth is not spherical.
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duncansteel at 15:15 PM on 31 October 2014Antarctica is gaining ice
Response to #309 point (2)
As you quoted from me: "...it appears that these intra-annually varying insolation changes cannot be ignored." I emphasized that those particular plots were over a full millennium, so that people would not be misled. Although the insolation changes are not linear, to a good approximation the changes I calculated are between -2.0 and +1.1 W/m2. The latest (2013/14) IPCC AGW forcing estimate is 2.3 W/m2; in the 2007 report it was 1.6 W/m2. Therefore, as I stated, "...it appears that these intra-annually varying insolation changes cannot be ignored." Note that the only natural change admitted to the 2013/14 IPCC report is an intrinsic variation in intrinsic solar output of order 0.1 W/m2.
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duncansteel at 15:09 PM on 31 October 2014Antarctica is gaining ice
Response to #309 point (1)
I am not trying to convince anyone of anything. Eventually the truth will come out and be recognised. As noted already, this work has already been peer-reviewed by several (about ten, from memory) people who have expert knowledge in the area (e.g. 20+ years experience post-PhD), and none has found any error; indeed, most are astonished by the rather silly mistake I have identified in various climate change papers where the authors have assumed that they can subtract the insolation at a certain ecliptic longitude in one epoch from that in another and that the result gives them the insolation change.
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duncansteel at 15:00 PM on 31 October 2014Antarctica is gaining ice
Responding to #307:
Rob Honeycutt asked:
"You're clearly capable of publishing research. So, if you're so confident of your "essay" why is it not published in a respected peer reviewed journal?"
The answer is because I make my living generally in other ways than gathering funds from government grants, and therefore do not need to publish in journals (in order to gather yet more grants); and also choose not to spend the considerable time required putting things into the necessary format for journal publication. On my own website I can publish what I like, and what I believe to be correct, without being forced by referees with vested interests to alter what I want to say.
In terms of actual publication of the more-complete story in that 'essay' (someone else's term for it), it will eventually appear as a monograph published by a leading university press, in perhaps a year from now.
You wrote: "I did a quick search and couldn't find anything by you on this subject." Ummm. The subject here, as such, is celestial mechanics: the insolation changes come about directly from understanding the celestial mechanics. That is an area in which I have a record of something like 140 (peer-reviewed!) original research papers, four books in several editions, many book chapters, around a thousand articles in major newspapers and magazines, and ... But none of that means anything, in terms of whether my calculations of the insolation changes are right or wrong. They either are, or they're not.
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Tom Curtis at 12:29 PM on 31 October 2014Antarctica is gaining ice
duncansteel @305:
1) It is not me or the readers here you should be trying to convince. It is the editor and peer reviewers of a suitable journal who will be far more able to pick up any errors in your assumptions or calculations than I. That you have avoided that step shows you are more interested in propoganda (or book sales) than in science IMO.
2)
TC:"As it happens, he is claiming AGW is a smaller contributing factor because the difference in his calculation sprind insolation (on a particular day) over a 1000 years is greater than the radiative forcing over the last 250 years. "
DS: "No. I gave plots for both the past 1000 years and also the past 250 years..."
From the blog post:
"I note in passing the scale showing the changes in insolation for the correct (left-hand) graphic. These changes range from ─8.1 W/m^2 up to +4.4 W/m^2 (over a full millennium). Recalling that the IPCC has estimated that the AGW climate forcing is about 2.3 W/m^2, it appears that these intra-annually varying insolation changes cannot be ignored."
3)
"On the item in parentheses "(on a particular day)" - no, I used that red bar to illustrate the change at the vernal equinox, but the graph that was copied above from my website has the overall intent of showing that the insolation over the (almost complete) first half of the year is higher than in the second half of the year. That is, at each instant during the first half of the year the insolation is greater than at the equivalent instant in the preceding year"
I showed a copy of one of those graphs, so it was quite clear as to your intent. The "on a particular day" draws attention to the fact that the calculated values reported in the text only apply on that day (with other days typically having a reduced effect), and to the fact that over the full year, the net effect is very near zero.
4)
TC: "Unless you wish to entertain a change in the laws of thermodynamics so that they only apply on the spring equinox, that alone refutes his conjecture."
DS: "As I noted above, the insolation changes (some positive, some negative) continue across the whole year; they are also latitude dependent, as I show in some detail. The spring equinox is simply an astronomically-defined instant used to register the years against each other."
Perhaps you have difficulty recognizing sarcasm. In virtue of the fact that the total insolation is effectively unchanging, the net effect on the Earth's energy balance over the full year is also likely to be effectively unchanging (on which more later).
5)
TC: "Further, his theory does not even match the evidence. As noted, his theory predicts a near linear change over the last thousand years."
DS: "Entirely incorrect statement. Not only are the insolation changes not linear, but also the consequences are not to be expected to be linear, as I explain in the essay."
This is in some ways the crux of the issue. In his blogpost DS writes:
"The precession of perihelion therefore is causing not only the nature of the seasons to alter, through the intensity of the sunlight arriving at the Earth changing for corresponding times of year, but also the lengths of the seasons are varying for the same reason. Obviously enough, this must cause the climate to change in different ways in different locations."
From this, and other related passages, I formed the idea that the effect DS describes is a function of the precession of the perihelion (relative to the vernal equinox). Here is DS's plot of the precession of the perihelion:
It may not be precisely linear, but for the time scale involved its departure for linearity is non-consequential.
Of course, DS can (and should already have) calculated the change in insolation at the northern spring equinox over the last thousand (or two thousand) years, and plotted it against changes in temperature over the same period. Such a plot would largely resolve this issue one way or another. He may also want to do the same for his calculated change in annual energy budget (due to differences in albedo at different locations and seasons along with the changing time of insolation). If either plot shows a hockey stick shape with an inflexion point in the late 19th century, he may be on to something. If not, the emperical data, which he has been so carefully avoiding, refutes his hypothesis.
(More in a following post)
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Rob Honeycutt at 12:18 PM on 31 October 2014Antarctica is gaining ice
"Curtis ended: 'I would not waste my time on it.' - Well, he didn't. He has made it clear that he did not read my essay, nor understand it..."
Ruh-roh.
I don't think Mr. Steel is familiar with Mr. Curtis.
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Rob Honeycutt at 11:28 AM on 31 October 2014Antarctica is gaining ice
duncansteel... Quick question in response to the repeated comment "in my essay."
You're clearly capable of publishing research. So, if you're so confident of your "essay" why is it not published in a respected peer reviewed journal?
I did a quick search and couldn't find anything by you on this subject.
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duncansteel at 11:27 AM on 31 October 2014Antarctica is gaining ice
Responding to #304: " (eg see the results for the forcing in common use here.)" The linked page is the specific NOAA resource to which I have drawn attention in terms of incorrect application of valid data. Berger's results for the latitude-dependent insolation are made available there. Those values are tabulated for equal steps in ecliptic longitude (30-degree steps from the vernal equinox defined as the zero point) in different epochs. However, equal steps in ecliptic longitude are not equal steps in time! That is, the steps are not each 1/12th of a year. Therefore, when one takes from that website the values for 1950 CE (Berger's "present") and for 950 CE (one millennium previously), you cannot subtract the value for the first epoch from that in the other in order to deduce an insolation change! This is precisely what many climatologists have done, because they do not understand Kepler's Second Law. This really is pretty simply stuff - anyone who has done Astronomy 101 should be able to follow it - and yet no-one seems to have pointed it out previously.
To summarise: the insolations from Berger on that website are valid, but one cannot subtract his insolation values in one epoch from those in another if one wants to know the insolation change, because the insolations presented there are not for consistent time steps during the year: the time steps vary from epoch to epoch due to apsidal precession. The way one could achieve valid values for insolation changes - as I did, as a check on my own independent calculations - is to download Berger's FORTRAN program from his FTP site, and run it for equal time steps (e.g. day-by-day time steps) for any two epochs one might like to choose: say 1900 and 2000. The differences in the daily insolations between the two epochs will then show how much the insolation has actually changed at each and every latitude you care to chart.
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duncansteel at 10:46 AM on 31 October 2014Antarctica is gaining ice
This is a brief response to #299 from Tom Curtis, after someone kindly pointed it out to me.
Virtually everything in #299 is incorrect.
"As it happens, he is claiming AGW is a smaller contributing factor because the difference in his calculation sprind insolation (on a particular day) over a 1000 years is greater than the radiative forcing over the last 250 years. " - No. I gave plots for both the past 1000 years and also the past 250 years; and note that from 1000 CE through to 1246 CE perihelion is approaching the winter solstice, then passing it, and since then having an accelerating effect on the insolation variation. On the item in parentheses "(on a particular day)" - no, I used that red bar to illustrate the change at the vernal equinox, but the graph that was copied above from my website has the overall intent of showing that the insolation over the (almost complete) first half of the year is higher than in the second half of the year. That is, at each instant during the first half of the year the insolation is greater than at the equivalent instant in the preceding year, if one registers the years against each other on a scientific basis (rather than using calendars that are based on religious considerations).
"The effect he calculates appears, however, to be linear over time" - No, not at all, and I state that in my essay; and have said so again above. Now, that statement I have just made applies to the insolation itself, but a far greater non-linearity to be anticipated, and which I discussed in my essay, is the effect of the changing insolation in terms of altering the albedo values and distribution, and therefore the overall consequences of that changing insolation.
" In fact, the total effect sums to zero over the course of the year so that the net forcing from his mechanism is in fact zero." - The statement is false. I explained in my essay in some detail, and several times, the ice albedo feedback effect, and gave an illustrative calculation. Curtis appears to have missed that. It would seem fairly obvious that an increase in the insolation in the first half of the year, and a reduction in the second half of the year, must have some effect in terms of climate change. This insolation change appears to have been hitherto missed in all reports and papers I have read, and you will not find mention of it in the IPCC reports. I have drawn attention to it in the hope that its overall effect can be assessed.
"Unless you wish to entertain a change in the laws of thermodynamics so that they only apply on the spring equinox, that alone refutes his conjecture." - As I noted above, the insolation changes (some positive, some negative) continue across the whole year; they are also latitude dependent, as I show in some detail. The spring equinox is simply an astronomically-defined instant used to register the years against each other.
"Further, his theory does not even match the evidence. As noted, his theory predicts a near linear change over the last thousand years." - Entirely incorrect statement. Not only are the insolation changes not linear, but also the consequences are not to be expected to be linear, as I explain in the essay.
"Berger (1978), from whom he draws his algorithms" - False statement. I did not draw my algorithms from Berger's wonderful papers. I derived the algorithms from first principles. It was only after the fact, when I saw what my results must imply, that I turned to Berger's FORTRAN program to do check calculations, as I have described in some detail. It is noteworthy that, as I discuss in my essay, essentially the only parameters needed in order to derive a good-enough calculation of the insolation changes are the lengths of the mean tropical year and the anomalistic year. The difference between those indicates the circa 58 years it takes perihelion to shift by one day closer to the vernal equinox. The use of the changing orbital eccentricity and obliquity of the ecliptic is nice, for completeness, but over only a century or two those slowly-altering values have little effect. Just the comparative values of the two year lengths are all that is required, to first-order.
The rest of the paragraph by Curtis discussing Berger (1978) is also entirely incorrect. In all his calculations Berger uses the vernal equinox to register the years against each other, whether he is making calculations of insolations in equal steps of the true anomaly or the mean anomaly. Unfortunately it is necessary to have a good command of the celestial mechanics involved if one is to be able to understand Berger's papers. If one does not understand the language/jargon, then stepping through Berger's FORTRAN program line by line may be instructive.
"his refusal to calculate a total year energy balance" - At this stage, no such calculation can be made, because I have calculated in detail only the changes in the incoming energy (the insolation) as a function of time-of-year and latitude; I have estimated also the effect upon the insolation absorption through a change in the Arctic albedo. Because I have not looked at the re-radiation, of course I have not calculated a "total year energy balance" - to state that is like complaining that I have not discussed the history of the Louvre in Paris: it's not relevant.
In any case, no balance is to be expected! Things are changing; and what I have introduced here would seem to be a major contributor to that change.
"inflation of the effect by using unequal comparison times" - Untrue. I used the interval 1750-2000 in most cases, using the past millennium (1000-2000) when I was driven to do so by considerations such as avoiding too-close cluttering in graphs and plots. In terms of criticizing specific comparisons of figures, Curtis misses the opportunity to note that the IPCC AGW climate forcing figure is for the whole Earth surface (4 pi r2) whereas the insolation is intercepted by only a quarter of that area (pi r2).
"a hypothesis he has not presented for peer review" - False statement. I have had it reviewed by several of my fellow astronomers with expertise in celestial mechanics (i.e. true peers), and I have presented it in research colloquia to others with broad astronomical expertise. As of yet no-one has found any flaw in my analysis/calculations. I have made a fairly simple-level account available on my website, and it is available for review by anyone. If someone out there can identify an error, please do let me know.
Curtis ended: "I would not waste my time on it. " - Well, he didn't. He has made it clear that he did not read my essay, nor understand it, just as he has demonstrated his lack of understanding of Berger's work.
karly: Thank you, appreciated.
The natural phenomenon I have described in my essay and associated graphics and movies (see http://www.duncansteel.com/archives/category/climate-change) is a surprising omission from previous climate change/global warming modelling. All constructive, valid criticisms and debate are welcome. The reality is, though, that one will need a good command of fundamental astronomy and celestial mechanics in order to understand what is going on, and so be able to identify any flaws, if they exist. True scholars are always pleased if someone identifies an error in their own calculations: that's the way we move forward.
Moderator Response:[PS] Fixed link. Please note our comments policy, and in particular avoid bulk quoting. It is easier to refer to the original.
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Ken in Oz at 10:36 AM on 31 October 2014Republican politicians aren't climate scientists or responsible leaders
It does sound like McConnell chooses to avoid openly stating his true views ie will not unequivocally say that he rejects mainstream science on climate. This is how Conservatives here in Australia work; what they say can and will strongly suggest that they reject the science but, through being uninformative, vague and contradictory they retain the the option to deny that they deny. For audiences that agree with them their sidestepping and occaisional concessions that climate is a real issue is made to look like a mocking and insincere submission to an imaginary eco- political correctness. ie forced on them by the unfortunate popularity of environmentalism. Those that take the issue seriously are no more fooled than those that reject it - but a big portion of community and voters, who aren't well informed and hold no strong views look to leaders to know what they are about - and are being let down.
With this style of politicking, direct expressions of rejecting science tend to come from a smaller group of outspoken colleagues or from allied conmentators, which can be used both to say what's not expedient to say directly as well as make their own utterances seem more moderate. It's really about doubt and delay and keeping climate lower down in community concerns. When the problem is one that's ongoing, cumulative, with long delayed impacts with costs that will come out of irreplaceable capital, delay, like ignoring the abundant and clear expert advice from peak science agencies is dangerously irresponsible.
It's deeply dismaying to think that the next Republican US President could very well come to office with a conviction that climate science is wrong and that climate as a policy consideration must be eliminated as far as possible from government business - like Australia's Prime Minister is doing - hinting at but never clearly articulating that belief or goal. Like Australia's Prime Minister did.
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Phil at 09:05 AM on 31 October 2014There is no consensus
KR @636
We can also note that even when scientists are wrong, they are often right enough (e.g. Newton's laws of motion)
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scaddenp at 07:03 AM on 31 October 2014Antarctica is gaining ice
Milankovich first did these calculations by hand in jail in 1913 and they have been repeated many times by other researchers (eg see the results for the forcing in common use here.) When someone says they have done them and got a different result and yet not published it, then I am, shall we say, very skeptical. Publish the results and show why the standard ones are wrong and then we might be interested.
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There is no consensus
Andy Robinson - We can certainly agree on that, as well as noting that
- d) Usually the majority of experts are indeed correct, and
- e) Holding minority positions (far less than 1% per hypothesis, as there are multiple and contradictory proposed 'climate skeptic' mechanisms) means holding to a position that most people familiar with the subject(s) feel is in no way credible.
- f) For people not deeply versed in a complex subject, expert opinion makes for the most reasonable heuristic in deciding policy - to do otherwise is a very bad, and in fact irrational, bet.
To act as if the minority opinions are in fact correct is to fall prey to the Galileo fallacy - if people perceive you to be wrong, you usually are wrong. There are far far more loons doing living room 'science' than actual geniuses out there.
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Andy Robinson at 05:43 AM on 31 October 2014There is no consensus
If we acknowledge that 97% of climatologists agree with the concept of anthropogenic global warming can we a) agree that 97% is less than 100%, and b) that scientists have, throughout history, repeatedly come to majority conclusions that were wrong, and therefore c) admit that consensus on issues of scientific inquiry conveys no moral or intellectual prerogative?
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MA Rodger at 02:50 AM on 31 October 2014New research quantifies what's causing sea level to rise
The title of this study by Perky et al. is "Relative contributions of ocean mass and deep steric changes to sea level rise between 1993 and 2013." The two methods used to calculate the SLR due to mass increase give the same results but for different (overlapping) periods. The Abstract suggests identical results stating:-. "The global mean trend of ocean mass addition is 1.5 (±0.4) mm yr-1 for 1996–2006 from the residual method and the same for 2003–2013 from the GRACE method." And the post says this agreement extends to regional measurements.
Yet there has surely been an acceleration in global ice loss. In recent years GRACE is showing something like 750Gt ice loss per year from Greenland, Antarctica & other glaciers which would equal 2mm yr-1 So I'm not sure it is entirely correct to say the two methods yield a complete agreement given we should perhaps be expecting a difference for the two periods as ice loss has accelerated.
Of course, the other ingredient in changing ocean mass is changes in land water storage (recently put at +0.77mm yr-1 SLR by Pokhrel et al (2012) averaged for 1961-2003) which might be recently providing a compensating deceleration.
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Dikran Marsupial at 22:14 PM on 30 October 2014Antarctica is gaining ice
Karly@300 The purpose of this site is to discuss the strengths and weaknesses of scientific arguments. If you raise a scientific argument here, then you should expect its strengths and weaknesses to be discussed. It seems unreasonable to then say " If you believe his analysis is erroneous, please respect his request, and discuss the matter with him directly." as if Tom's post was disrespectful by discussing the problems with the theory here.
The WWW is already too full of misinformation, especially on climate, and so those with theories they wish to promulgate really ought to submit their ideas to peer review to give a reasonable chance for obvious flaws to be pointed out, rather than promulgating them immediately to laypersons who might accept them without seeing the flaws.
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