Discussion > Best evidence: The story so far.
BBD: "aerosols are not CCNs. They can *become* CCNs"! W.r.t. our "discussion" above: Isn't this undeniable evidence of a troll?
And BBD didn't notice - or is denying - that I am engaged in this thread since the beginning. Nice to watch how his houses of cards in cloud-cuckoo-land are collapsing.
And since BBD didn't respond to my question above, again: The "attributed" CO2 forcings (which BBD obviously seems to regard as "best evidence") are a house of cards.
I don't think we should accept a house of cards as best evidence that we have to follow/pay the BBDs of the world.
September 2011
The WMO recommendation/standard is 30 years = climate.
According to my fag packet calcs the 30 year monthly running trend for HadCRUT3 peaked in Dec 2003 at 0.19C per decade or 1.9C per century.
As of March this year it stands at 0.15C per decade or 1.5C per century. A significant reduction for an 8 year period.
As something approaching 75% of the doubling carrying capacity of CO2 has already taken place why should we conclude that the rate of increase, should it continue, be any greater than 1.5C per 100 years? Especially as the rate of change has been decreasing over the last 8 years and could well continue to do so.
Green Sand
"Climatologically significant effects means effects that are demonstrably affecting GAT over climatological (multi-decadal) period"
The question is not what is meant by 'climatologically significant", but on how to *demonstrate* it. In a noisy system which is moving up and down at all timescales.
You don't demonstrate something by just saying it (over and over again, and calling people names).
I think the answer to rhoda's question is obvious at one level: the difference in measured/measurable radiation is minuscule and immeasurably small, if any, since such a signal is simply swamped by noise over a 30-year period.
shub
No takers on the Laschamps excursion? Well colour me surprised... As I said, I do not see any evidence that you are interested in evdience.
Busy this morning, so quickly:
matthu
So now BBD is modelling himself on RB and trying to acquire authority by association? FAIL
No, I'm pointing out that I'm not alone in finding it impossible to have a reasonable discussion in comments here. And not for want of trying. But true to form, you wilfully misunderstand the message.
September 2011
W.r.t. our "discussion" above: Isn't this undeniable evidence of a troll?
Why? You were wrong about aerosols *being* CCNs. So why am I a troll for pointing this out?
And since BBD didn't respond to my question above, again: The "attributed" CO2 forcings (which BBD obviously seems to regard as "best evidence") are a house of cards.
Not even worth arguing (see previous page - GE denial)
Green Sand
As of March this year it stands at 0.15C per decade or 1.5C per century. A significant reduction for an 8 year period.
Usual evidentially weightless 'sceptic' cherry-pick of a meaninglessly short time period.
Shub
The question is not what is meant by 'climatologically significant", but on how to *demonstrate* it. In a noisy system which is moving up and down at all timescales.|
Sustained correlation over long (>50yr) periods is a useful indicator. Otherwise just more GE denial and not worth arguing about; no hope of bridging the comprehensional chasm.
You don't demonstrate something by just saying it (over and over again, and calling people names).
One has to smile.
BBD
"Sustained correlation over long (>50yr) periods is a useful indicator. "
Dude, you can get correlations over even longer periods and yet be wrong. Like I said, this is a noisy system with variability at all timescales we're talking about. That means, it is easy to fool oneself.
Why don't you just say:
there are many indirect indicators that the planet has warmed as a whole. The warming has coincided with the first instance of extensive release of CO2 into the atmosphere by humans. CO2, in our understanding, has the capacity to produce warming. This understanding has its basis in well-understood physics, but what exactly will happen in a system dominated by another greenhouse gas, namely water, whose different phases have opposing effects on climate, cannot simply be deduced. So we use climate models. And if we put the best of our understanding into a model, it does warm its planet. This is the best I've got. However I don't have what you are asking for.
shub
BBD - I am happy to look at the Laschamps excursion - it certainly looks like evidence - but I am not certain that it is relevant to what we were discussing. For instance, Wiki says this:
Possible relationship to climate
There is evidence that geomagnetic excursions may be associated with episodes of rapid short-term climatic cooling during periods of continental glaciation
and we were actually looking for demonstrable evidence of positive CO2 feedbacks over a climatological period.
Reminder; we all agree that CO2 should have an effect - but the size of the effect may be limited by the strength of the feedbacks, right? So we need demonstrable evidence of the size of the feedbacks. And you come up rather cryptically with the Laschamps excursion.
But if you can show the relevance, you may attract more attention.
matthu
Remember, guys, BBD wants Watts to be wrong.
Why he should want the warming trend in the US (and by implication maybe even the rest of the earth's land mass) to be double what it might turn out to be (I'd better stress 'might' to head off at least one of his red herrings) only he can explain. Though I doubt he will.
If the results turn out to be even partially correct then it looks as if we are left with one or two interesting possibilities.
1. Feedbacks are at least less positive than the "sciencey people" would have us believe with the result that warming is not something we need worry about.
2. Spartacus (or my dog, or whatever sock he's currently keeping his puppet in is called) may be onto something with the argument that above a certain concentration CO2 is irrelevant — but the long-awaited paper on this subject would be nice !!!
3. Allied to 2, the cosmic ray hypothesis is still worth further investigation even though BBD claims that it's not worth the time because, according to him, it has to be proved before you can investigate it. Eh?
I wonder what in BBD's mind is not to like?
Do you actually want catastrophic global warming, BBD? It would be nice to know.
Mike Jackson
matthu
The Laschamp excursion is pretty much the nail in the coffin for GCR-climate effects. I'm fed up with doing all the explaining - dig deeper. Be a *proper* sceptic for once. Find out what happens to GCR flux when there is a massive and sustained reduction in the Earth's magnetic field. Look at the Be10 proxy spike ~40ka. Then look for a climate signal. Do some work.
BBD
shub
there are many indirect indicators that the planet has warmed as a whole. The warming has coincided with the first instance of extensive release of CO2 into the atmosphere by humans. CO2, in our understanding, has the capacity to produce warming. This understanding has its basis in well-understood physics, but what exactly will happen in a system dominated by another greenhouse gas, namely water, whose different phases have opposing effects on climate, cannot simply be deduced.
As I keep on saying, if feedbacks net negative or even neutral, nothing much happens. Glacial terminations cannot happen under orbital forcing, you don't get warm periods, be they Minoan, Roman or Mediaeval, nor do you get cool fluctuations like the LIA under *apparently small* changes in forcing. It is a physical impossibility.
A responsive climate - such as observed - requires that feedbacks net positive. It's really very simple once you get the denial goggles off and think objectively.
BBD
The Laschamp excursion is pretty much the nail in the coffin for GCR-climate effects.From Wikipedia:
Since no [geomagnetic] excursions have been recorded within human history, it is unknown precisely what effects one would have. However, it is likely that nothing serious would occur, as the human species has certainly lived through at least one such event; Homo erectus and possibly Homo heidelbergensis lived through the Matuyama reversal with no known ill effect, and excursions are shorter lived and do not result in permanent changes to the magnetic field. The major hazard to modern society is likely to be similar to those associated with geomagnetic storms, where satellites and power supplies may be damaged, although compass navigation would also be affected.So where is your evidence that Laschamp is "the nail in the coffin"? The only reference I found to climate was the one I have quoted above.
'''
There is evidence that geomagnetic excursions may be associated with episodes of rapid short-term climatic cooling during periods of continental glaciation.
You might like to have a look at
Rusov et al:Galactic Cosmic Rays – Clouds Effect and Bifurcation Model of the Earth Global Climate. (Journal of Atmospheric and Solar-Terrestrial Physics Vol. 72 (2010))
Mike Jackson
BBD, I pointed to the fact that (all!!?) sources are stating that aerosols are cloud condensation nuclei (CCNs). You asserted repeatedly that aerosols are not CCNs. Where is your source?
I said also: "The 'attributed' CO2 forcings (which BBD obviously seems to regard as 'best evidence') are a house of cards."
You wrote in response to that in an arrogant manner: "Not even worth arguing (see previous page - GE denial)"
BBD, look what Kevin Trenberth wrote in a CG email (17 Oct 2000, #0869.txt) (my highlights):
"It relates to the large uncertainties in the aerosol forcing and the failure of chapter 6 to add up the forcings and address the issues that arise in doing so. In chapters 9 and 12 these things have to be confronted and assumptions are made. At some point there is some circular reasoning because the main constraint is the observed record of warming, and that places constraints on the magnitude of the negative radiative forcing from aerosols and couples any other changes in aerosol radiative forcing to the sensitivity response to GHGs, as John says.This also hinges on other aspects and they are the magnitude of natural variability and thus the revailing view that the warming observed is now well outside the realm of natural variability and thus it is forced and predictable and can be linked to the forcings.
You can argue that this is a house of cards but the building is getting stronger.
I now worry that this has not helped.
Kevin"
As you should know, BBD, there has been no statistical significant warming since then (~2000). It seems we can argue that this is a house of cards and the building is getting weaker, can't we?
September 2011
... if feedbacks net negative or even neutral, nothing much happens. Glacial terminations cannot happen under orbital forcing, you don't get warm periods... nor do you get cool fluctuationsOK. Let's take that at face value.
First question. Are you defining "positive feedback" as the same thing (or much the same thing) as a "forcing"? (No, I'm not being dim; I'm just aiming to make sure we agree on terminology!) And if you are can we agree that positive feedback can reinforce a cooling as well as a warming?
Once we 've agreed on the terms I can move on to the second question.
Mike Jackson
September 2011
BBD, I pointed to the fact that (all!!?) sources are stating that aerosols are cloud condensation nuclei (CCNs). You asserted repeatedly that aerosols are not CCNs. Where is your source?
It is general knowledge. However, for a detailed run-through of the science (emphasis on CERN-CLOUD experiment) see here.
If you read this carefully, you will understand my oft-repeated point. You will also be required to concede that you are wrong to state that aerosols *are* CCNs. As I said, under the right conditions, some aerosols can *become* CCNs.
Busy. More later, time permitting.
BBD
BBD
Usual evidentially weightless 'sceptic' cherry-pick of a meaninglessly short time period.
Now you are going to have to explain, (civilly and politely please, you are in the Bishop's House) how your statement above relates to the rate of change in a 30 year running mean as dictated by the WMO befits the title “climate”.
If you are referring to the March cut off the reason is simple, when quoting my own numbers I always try to gain independent confirmation. In this case I used Wood for Trees:-
"File: hadcrut3gl.txt
#
#Time series (hadcrut3) from 1850 to 2012.25
#Selected data from 1982.25
#Selected data up to 2012.17
#Least squares trend line; slope = 0.0153446 per year
1982.25 0.0394286
2012.25 0.499767
#Data ends
#Number of samples: 2
#Mean: 0.269598"
http://www.woodfortrees.org/data/hadcrut3gl/from:1982.25/to:2012.17/trend
WfT have not updated HadCRUT3.gl since March, so without having confirmation of the last three months I did not include them, however my calcs show that they make no change to the 1.5c per century trend (3 months in 30 years not being likely to) and we will be able to check when they do update.
If it is thought that 8 years is “a meaninglessly short time period” how do we approach the less than 5 year period that it took for the 30 year trend to go from 1.5c in early 1999 to 1.9c in Dec 03, was that meaningless?
The talk is very often about theoretical rates of warming, where as this is what is actually happening. The planet, using the WMO 30 year trend assessment principle has never been over 1.9c per century and has now reduced to the present 1.5c. Where it goes next I don't know, time will tell.
This is actual observational data. Not cherry picked, it is not possible to cherry pick the last 30 years i.e. where we actually are in the here and now.
Green Sand
Thought I'd re-post this from unthreaded as it seem relevant to this thread:
How do stars form?
VIA GRAVITATIONALLY INDUCED ATMOSPHERIC HEATING.
What drives global warming on atmospheric planetary bodies such as Earth and Venus?
GRAVITATIONALLY INDUCED ATMOSPHERIC HEATING.
Look up the detailed research of Nikolov and Keller among MANY other qualified scientists.
PROVE it ain't so because NOBODY has EVER PROVED CO2 to be the cause!
Let's get back to basic physics and ignore the politically motivated CO2 alchemy - and save our economy in the meantime.
If the CO2 groupies can't PROVE their case beyond doubt they're just discussing metaphysics.
By the way, present temperatures are slightly better than those of the Little Ice Age which ended around 150 years ago - about the time the CO2 fanatics use to compare today's temperature with. (What is that enormous rise - around 0.7 to 0.8 degC?)
RKS
BBD
The Laschamp excursion is pretty much the nail in the coffin for GCR-climate effects. I'm fed up with doing all the explaining - dig deeper. Be a *proper* sceptic for once. Find out what happens to GCR flux when there is a massive and sustained reduction in the Earth's magnetic field. Look at the Be10 proxy spike ~40ka. Then look for a climate signal. Do some work.
Have you or anybody else brought these concerns to Svensmark's attention?
The purpose of this thread is to provide the evidence - not to send people off to do research. So if you want to link your thought processes up into a coherent thread, please do so. Otherwise don't expect others to do your work for you. (Shades of Gergis here!)
matthu
BBD, saying that under the right conditions some aerosols can *become* CCNs is not the same as saying: "Aerosols are not CCNs." Right?
PS (see above): It is "worth arguing" that you build a house of cards, isn't it?
September 2011
BBD
I have re-posted my 2.49 comment to a new thread "Feedbacks and Forcings". I think the subject is worthy of discussion.
Mike Jackson
"As I keep on saying, if feedbacks net negative or even neutral, nothing much happens. Glacial terminations cannot happen under orbital forcing, you don't get warm periods ...etc"
These fed-back changes and glaciation-related changes act over timescales of tens of thousands to hundreds of thousands of years. At all lower timescales, the inherent variability - 'caused' no doubt by multiple influencing factors - dominates.
If you don't get the timescale perception right, you fall into the hole that Hansen pushes people into.
And STFU with the namecalling.
shub
BBD - you do realise that nobody - not even Svensmark - is claiming that GCR on their own affect the climate?
That you may need to have other factors present too?
So in order to properly discount GCR - as you appear to be trying to do - you need to demonstrate what the other important factors are and then prove that they were also present during the Laschamp excursion. I don't think you have done that yet.
matthu
Green Sand
If you are referring to the March cut off the reason is simple
No, I was referring to your use of 8 years instead of a 30yr climatology. You cannot infer anything from 8 years. Some points:
- Hadcrut3 (gl as you use, or vgl) is obsolete
- Hadcrut3 runs cool compared to all other surface temperature reconstructions
- Currently flat trend in GAT is likely because of a combination of factors, eg diffusion of heat into deep oceans, increased sulphate loading from Chinese coal, predominantly La Nina conditions and quiet SC24
Instead of cherry-picking your data set and methodology, do it properly: with a third-order polynomial fit to something other than Hadcrut3, eg NOAA global or GISTEMP. Or indeed Hadcrut4, despite its not being quite up to date. As you say, a bit at the end makes no difference to the big picture.
BBD
Well ... some evidence given to the Senate Committee Environment & Public Works Committee today:
The average warming rate of 34 CMIP5 IPCC models is greater than observations, suggesting models are too sensitive to CO2.New discoveries explain part of the warming found in traditional surface temperature datasets. This partial warming is unrelated to the accumulation of heat due to the extra greenhouse gases, but related to human development around the thermometer stations. This means traditional surface datasets are limited as proxies for greenhouse warming.
Widely publicized consensus reports by “thousands” of scientists are misrepresentative of climate science, containing overstated confidence in their assertions of high climate sensitivity.
No quarrel with that.
matthu
matthu
Have you or anybody else brought these concerns to Svensmark's attention?
I believe Richard Alley pointed out the little problem with the Laschamp excursion and lots of people have tried to point out to Svensmark that his hypothesis is entirely lacking in support. Some are referenced above.
The Laschamp excursion resulted in a huge flux of GCRs to the surface and climate (then in a DO cycle) didn't respond. Not a twitch. Nowt. Sorry.
shub
These fed-back changes and glaciation-related changes act over timescales of tens of thousands to hundreds of thousands of years. At all lower timescales, the inherent variability - 'caused' no doubt by multiple influencing factors - dominates.
If feedbacks net negative or neutral, *nothing* happens at *any* time scale, including noisy internal variation. Without net positive feedbacks observed climate behaviour is a physical impossibility. Sorry.
September
BBD, saying that under the right conditions some aerosols can *become* CCNs is not the same as saying: "Aerosols are not CCNs." Right?
You were mistaken. Why not have the good grace to admit it?
BBD
If feedbacks were 'net' any one way or the other, the climate system would never display stability at the longest timescales.
The climate system is exceptionally stable at long timescales. Sorry.
Both positive and negative feedbacks, putatively, of course, can be said to exist, in a framework that characterizes climatic forces this way. The existence of positive feedbacks is not a automatic pre-condition that they start acting at human-relevant timescales. The influence of CO2 can said to be barely measurable at the thousand year timescale. In papers dealing with climatic/geologic eras, these changes are discussed using terminologies that are commonly used in everyday life. A simple failure to translate and hold their meanings separate between the different realms is what has happened with you. You will never dig yourself out of this hole. You have invested too much in your persona based on it.
More importantly, inferring feedbacks from climate behaviour does not constitute 'evidence.'
shub
@ Dung and Marion,
[blush] Thanks for the compliments; however, I must confess: I do have the pdf (and provide a handy link from my blog's sidebar, so that others can draw their own conclusions) ... but I am far from having read it all!
OTOH, I have read a good number of UNEP/Agenda 21 driven derivatives - probably far more than is safe if one wants to ... uh ... sustain ... a healthy level of blood pressure ... so I pace myself ;-)