Thx Danny, I think I’ll have a thread on Sunday discussing preferences for future topics
Comment on Blog discussions by curryja
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Comment on Climate sensitivity: lopping off the fat tail by curryja
as an example, IPCC makes some ‘very likely’ statements, associated with medium confidence.
the ‘very likely’ relates to the statistical distributions from their models or obs or whatever, then confidence level (low, med, high) relates to whether or not they believe the statistics.
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Comment on Climate sensitivity: lopping off the fat tail by Berényi Péter
That leaves the energy balance climate models using historical observations, which seem well suited to determining TCR. Nic Lewis analysis is arguably ‘best in class’, providing two recent analyses:
– AR5 forcing: 1.05 – 1.8C
– New (lower) aerosol forcing: 1.05 – 1.45C
Compare these values to the AR5 likely range for TCR of 1.o-2.5C.
Keep in mind, that the definition of TCR (Transient Climate Response) is the surface warming in response to an exponentially increasing atmospheric carbon dioxide content at the end of a 70 year period relative to its beginning when rate of increase is 1% per year.
Considering actual CO2 data, average annual increase during the 56 years between 1959 and 2014 was 0.43%, which is substantially less than the 1% we have seen in the definition of TCR.
If we assume the same rate for the next 70 years, 1.45C TCR implies 0.6C warming by 2085 relative to current temperatures, hardly catastrophic.
However, it is unlikely that CO2 concentration can keep growing exponentially for so long, because carbon based fuels, even with no “carbon tax”, are getting ever more expensive, while nuclear energy is getting cheaper.
Moreover, it is pretty meaningless to look beyond a 70 year horizon, because on that scale technology is expected to evolve to something completely different. It may well become a net consumer of atmospheric CO2, because with the advent of molecular nanotechnology carbon will be the default construction material of almost everything, due to its chemical versatility, and it is readily available in the atmosphere everywhere, as we can learn from plants.
The concept of ECS (Equilibrium Climate Sensitivity) has no merit. Even theoretically it is pretty independent of TCR, but it can only be substantially higher than that over a very long period, that is, it has neither economical nor political significance, for on a timescale like that society itself is in thorough disequilibrium.
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Comment on Climate sensitivity: lopping off the fat tail by Lucifer
Of course, we should also include AGW’s greatest hits:
1. Close to the predicted temperature trends since 1979 ( still below low end but probably within margin of error ).
2. Stratospheric cooling, least near tropopause, greatest near stratopause.
3. Arctic warming greater than globe
4. Arctic sea ice loss ( though could just be a repeat of the 1910-1945 episode with commensurate warming ).
5. Sea level rise ( though some of this is from ground water mining and increased runoff that would have recharged ground water.
6. greater warming over land than ocean ( including for the UAH MSU data set ).
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Comment on Climate sensitivity: lopping off the fat tail by cerescokid
Thanks for the explanation. Getting through the verbiage and structure is tough enough and then I kept running into those terms. This helps.
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Comment on Blog discussions by justinwonder
Mark “… naive…president…”
True. I have been using the term “Orwellian” frequently, as have others.
http://www.wsj.com/articles/bret-stephens-the-orwellian-obama-presidency-1427153308
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Comment on Blog discussions by michael hart
“people forget that ATTP started off as a hostile, put down mirror image to WUWT, cheap shots, snide and nasty but providing a meeting place for people banned from Watt’s site and absolutely intolerant of Skeptics and their viewpoints.”
Oh no, I hadn’t forgotten it.
I was about to post something similar before Curious George drew my thoughts elsewhere by his description of Gavin’s problems with water.
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Comment on Climate sensitivity: lopping off the fat tail by Salvatore Del Prete
http://hockeyschtick.blogspot.com/2015/03/a-recent-seminar-presentation-by.html
More arguments against AGW.
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Comment on Temperature adjustments in Australia by john321s
euanmears:
There indeed is no good reason to ignore the 27 early years of data provided by only three stations. A legitimate way to treat that situation is to establish a “base period” much-longer than the traditional 30yrs–one that overlaps all the records–and average the yearly deviations (“anomalies”) from such respective means of each of the available records. While the sampling uncertainty will certainly be higher during early years than later ones, you will obtain UNBIASED estimates of yearly deviations throughout the entire time-interval.
This is crucial, because nothing–aside from UHI– biases estimates of the linear “trend” more than the surreptitious influence of time-interval selection in time-series whose spectral structure defies all theoretical models and descriptions.
John S.
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Comment on Blog discussions by michael hart
Steven Mosher | March 22, 2015 at 10:32 pm |
An experiment might me in order. What would happen if Jim D, Joshua and Willard and me decided to avoid commenting for a week or a month?
this place would quickly descend to WUWT levels where Tim Ball posts stuff and everybody rushes in to say “great post Tim!”
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An experiment where Steve ‘kinetics can tell you nothing’ Mosher agrees to treat his audience with correct spelling for a month?
Bring it on. How much extra do we have to pay to replace the other two?
I consider you in high enough regard to know some better critics than them.
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Comment on Blog discussions by David Springer
How about an article on how solar power spectrum changes as sunspots wax & wane and how the change in power spectrum effects which gas, liquid, or solid surface absorbs solar power and how much it absorbs.
Solar spectrum variation across sunspot cycles and, presumably, across grand maximums and minimums.
Solar spectrum changes far more than TSI. Different wavelengths have different absorption and reflection characteristics in the same given gas, liquid, or solid. This has potentially great implications on how the earth’s climate reacts to long term changes in solar spectrum lasting decades, centuries, and possibly millenia or even longer.
http://www2.mps.mpg.de/projects/sun-climate/resu_body.html
Solar irradiance variations show a strong wavelength dependence. Whereas the total (integrated over all wavelengths) solar irradiance changes by about 0.1% over the course of the solar cycle, the irradiance in the UV part of the solar spectrum varies by several to about 10% at 150-300 nm, and by more than 50% at shorter wavelengths, including the Ly-alpha emission line near 121.6 nm. On the whole, up to 60% of the total irradiance variations are produced at wavelengths below 400 nm (Fig. 4). These variations may have a significant impact on the Earth’s climate system. Ly-alpha, the strongest line in the solar spectrum, takes an active part in governing the chemistry of the Earth’s upper stratosphere and mesosphere. Also, radiation around 200 nm is important for photochemical ozone production, whereas the radiation at about 180-320 nm is the main heat source in the stratosphere and mesosphere.
Fig. 4. The relative contribution of different wavelength ranges to the total solar irradiance (red histogram) and its solar cycle variations (blue histogram). About 60% of the total irradiance variations over the solar cycle are produced at wavelengths shorter than 400 nm (marked by the light yellow area), whereas the contribution of this spectral range to the total irradiance is only around 8%. Note different size of bins: about 40 nm below 200 nm, 50 nm between 200 nm and 400 nm, 100 nm between 400 and 1000 nm and 500 nm at yet longer wavelengths.
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Comment on Climate sensitivity: lopping off the fat tail by RB
Lots of ideologuing going on here, not surprisingly. Many, including Held, have maintained that TCR, not ECS, is important for policy (on 100-year timescales). Which is a quite different perspective from the politically driven understanding above.
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Comment on Climate sensitivity: lopping off the fat tail by David Springer
Joshua,
Curry’s level of expertise is not a “subjective feeling” trollish one.
Judith A. Curry is an American climatologist and former chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology.
You should, as always, write that down. Perhaps on the wall where you live underneath the bridge.
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Comment on Blog discussions by climatereason
What we need is an article from Joshua.
Tonyb
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Comment on Climate sensitivity: lopping off the fat tail by Curious George
Can we actually measure the “climate sensitivity”? As long as it is only an input of models, but never an output of an actual measurement, we can discuss it ad nauseam. How many angels can dance on a tip of a needle?
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Comment on Climate sensitivity: lopping off the fat tail by Joshua
Why i love the climate wars.
==> ” Steve and Then There’s Physics– I see both of you are at a loss of words to try to explain… ”
Being not very bright or very knowledgeable, i have no way of distinguishing Salvatore’s appeal to self authority from that of Steve Fredricks or Carrick.
Funny how that works.
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Comment on Climate sensitivity: lopping off the fat tail by Steve Fitzpatrick
Ken Rice,
Perhaps you need to write what you are trying to communicate more clearly.
“you see you’re confusing a number of different things here and (not surprisingly maybe) ignoring feedbacks.”
I am not confusing anything. I am looking at the system in terms of a simple energy balance, which includes applied human forcing, the present temperature response (the Planck response) to the applied forcing (increasing heat loss to space), plus heat accumulation in the system. Feedbacks, which are certainly always present, have nothing at all to do with calculating an energy balance. I am puzzled why you think they are relevant here. At least we agree that about 26% of the IPCC’s estimated net forcing from human activities (that is, net of aerosol effects) is going into the ocean (and melting ice, etc). When you wrote:
“Not really, because surface temperatures are only associated with a small fraction of the excess energy entering the system due to increased atmospheric CO2; most of the energy goes into the oceans, as it is currently doing.”
It suggested that you think the surface temperature response due to increased forcing (“excess energy entering the system due to increased atmospheric CO2″) represents only a small fraction of the applied forcing… and that most of the energy from forcing goes into the oceans. (Though it is now clear that was not your intent.) If you had clarified that by ‘excess energy’ you meant not total forcing, but forcing less energy loss from the Planck response, then there would have been no confusion.
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Comment on Climate sensitivity: lopping off the fat tail by Ron Clutz
INMCM4 (It’s Not the Most Convenient Model) says what all the models say: the future will be warmer, just at a lower rate than the others–about 1C/century. It’s the best of the 42 we tested, but no model can project cooling.
https://rclutz.wordpress.com/2015/03/24/temperatures-according-to-climate-models/
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Comment on Climate sensitivity: lopping off the fat tail by David Springer
Faith ‘n Begorrah, m’lad.
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Comment on Climate sensitivity: lopping off the fat tail by ...and Then There's Physics
Steve,
I fail to see how what I wrote was all that difficult to understand. That you’re still claiming that the problem was my explanation and not your understanding is no great surprise.
At least we agree that about 26% of the IPCC’s estimated net forcing from human activities (that is, net of aerosol effects) is going into the ocean (and melting ice, etc).
No, we don’t and that is the bit that I was suggesting you’re somewhat confused about. Since you seem incapable of understanding what I write and since I have no interest in explaining it to someone who can’t even be bothered to think about things before responding, I shall not bother.
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