Sceptic Links Discussion

[olly aitch]

Sorry to go off at a bit of a tangent, but I'd like to post a link to Dr Steven Hayward's 50-minute documentary "An Inconvenient Truth, or Convenient Fiction?".

I've just finished watching part 1 (it's viewable online, though I would recommend a Broadband connection!) and I'm waiting for Part 2 to buffer, so here's the link:

http://www.aconvenientfiction.com/

CB

I have just watched both parts & found it very well presented. It is another alternative viewpoint leaving me with more to consider.

[johnholmes]

welcome to Net Wx Ollie but could we have your town in your avatar please, then we all know where any weather reports are coming from?

many tks

[jethro]

Polykov's main emphesis is that the warming up of the artic is not in doubt (not that you could doubt it given the recent measurements). Rather he repeatedly argues that warming is due to natural cycles in ocean flow, predominently from the Atlantic and the post GS streams and THC drivers.

This is an arguement I have total respect for and it shows that non AGW theories can be peer reviewed as long as they are based on sound science.

The other side is below.

http://www.blackwell-synergy.com/doi/pdf/1...0.x?cookieSet=1

My personal opinion is that Polykov has successfully identified the key cycles over the past 100 years in determining natural climate variability in the artic.

However for the last 2 years the warming in the artic has moved up another gear, almost as if the natural variability is being enhanced (by IMO AGW).

I also think it's quite possible that a tipping point has been hit in the artic whereby the ice will not recover even in times of natural increases.

However I don't dismiss his views, it will be interesting to hear his views for 2007-2009 as to why the natural warming has continued to speed up and is now unprecidented in the last 100 years.

Matt

Thanks Iceberg, I like having the opposing view as it were, don't know about you but I sometimes worry that I may be blinkered in only seeing what I want to see. The popular presentation of Arctic Ice Loss all being down to AGW is propogated wholesale so when I started reading from reputable scientists that actually, natural drivers are, and always have been the major cause I did wonder if perhaps I was misinterpreting or not understanding them properly. Obviously not.

As with anything in climate studies, time lags have to be taken into account, perhaps this could explain the ice loss in the last couple of years? Afterall, it would take some time for oceans to register the full extent of any change in atmospheric cycles, my understanding of the current situation is the loss isn't caused so much by higher air temperatures but by warmer seas. If this is the case then it would take a few seasons for any negative patterns to re-emerge and register an ice recovery. I'll watch the area with interest but for now, nothing I've read so far has convinced me that AGW is over-riding natural cycles in this part of the world.

Well, I've watched Part 2 of the documentary now - it is well worth watching all the way through if you have the stamina. I would be very interested to hear any "Pro-AGW" views on the piece.

Has anyone else seen this?

No, I haven't, but I will when I'm less sleepy.

Edited July 9, 2007 by jethro

[Admiral_Bobski]

I have just watched both parts & found it very well presented. It is another alternative viewpoint leaving me with more to consider.

Hi Olly, and welcome to the boards!

I look forward to your future contributions

Ciao!

CB

[jethro]

Further to my post above, I've done some digging around this morning and found these which may shed some light on the situation. One of the links also includes measurements of the PDO up until Febuary of this year, it would appear that although there was a predominately negative phase in the late 1990's, it has since switched back again to more positive values. The Bond paper suggests the PDO has been in neither positive nor negative state conclusively. It would appear the jury is still out on whether or not we can expect the PDO to be negative or positive. The only certainty I can gather is that since the climate shift in 1976 it has been largely positive which would result in greater ice loss from the Arctic. There are obviously, yearly variations as nothing in climate is static but there has been no conclusive switch back to a negative state. I haven't read anything, anywhere that suggests the climate switch in 1976 was in anyway related to AGW.

I'd be interested to hear other's opinions on this.

http://www.pmel.noaa.gov/pubs/outstand/bon.../bond2613.shtml

http://www.beringclimate.noaa.gov/reports/np_04.htm

http://www.jisao.washington.edu/pdo/

http://www.agu.org/pubs/crossref/2006/2005JC003458.shtml

[BrickFielder]

The problem with being sceptical is that you need to try and explain why the climate models designed by some very clever people are not correct. In addition you need to explain why when the models are run using historical data they give results which closely match the resulting conditions. Showing that climate models can come up with the right answers about the past while being wrong about the future will be a difficult task. Perhaps the way to look at it is that the models are predicting the future correctly but for the wrong reasons. Far too often in climate science we see statistical evidence that tends to emphasize a point while lesser statitics are not readily quoted.

We see in articles how the artic sea ice is melting at an alarming rate,but nobody quotes the actual figures. For example the september ice minimum for around 1980 was 7.5 million square miles of ice where the 2006 minimum was around 5.9 million square miles which is about a 22% reduction.

One of the areas which concerns me is the assumption that increased cloud will have a positive feedback affect on global warming. Measurements show that outgoing longwave radiation has increased over the last 20 years by about 0.35 W/ms per decade (Cooling) due to less high level cloud.IPCC results show the net forcing of CO2 from 1750-2000 to be 2.3 W/ms which I assume is mainly in the last 50 years which would give 0.46 W/ms per decade (Warming). This looks to me like a negative feedback and for the models to be accurate then there must be an equivalent underestimation of positive feedback in another area.

Outgoing longwave radiation

How about another fact that 50% of the worlds oxygen is produced by phytoplankton and 30% of the worlds CO2 is absorbed by them. During the last 20 years there has been a reduction in phytoplankton of between 9% - 15% globally.

This looks most definately like a strong negative feedback. This may make little difference to the outcome in terms of global warming but it can alter how you tackle and place emphasis in dealing with global warming. It may well be equally important to tackle land usage as carbon dioxide emissions.

Stratospheric temperatures show marked shifts after the Agung ,el chichon and pinatuba eruptions which appear to force shifts in surface circulations a few years later. These signals quite clearly are still affecting global temperatures with a marked cooling at upper levels and warming at lower levels after each eruption. Its is a well known fact in climate studies but gets little mention when talking about warmer temperatures.

IPCC report on stratospheric and suface temperatures in relation to eruptions.

One of the known problems with many climate models is the aproximations for gravity wave drag and untill this starts to be resolved than climate models must be viewed with the knoweldge that there is inacuracy built into the models.Over the coming few years modelling is likely to improve significantly and we should expect a clearer picture to emerge.

Gravity waves

[jethro]

All very valid points BF, I've made similar points before, the sum total of all components has to be taken into account instead of this relentless fixation upon Co2. However, the models are no where near as accurate as that and have been fairly poor at hindcasting. I posted a few links a couple of pages back about their inaccuracy, here there are again for any who missed them.

http://neptune.gsfc.nasa.gov/STAFF/brianc/...on1popsumm.html

http://www.agu.org/pubs/crossref/2006/2005GL025127.shtml

http://neptune.gsfc.nasa.gov/STAFF/brianc/...rkpopsumm2.html

[Admiral_Bobski]

The problem with being sceptical is that you need to try and explain why the climate models designed by some very clever people are not correct.

In addition you need to explain why when the models are run using historical data they give results which closely match the resulting conditions. Showing that climate models can come up with the right answers about the past while being wrong about the future will be a difficult task.

One of the known problems with many climate models is the aproximations for gravity wave drag and untill this starts to be resolved than climate models must be viewed with the knoweldge that there is inacuracy built into the models.

Hi BF,

I've edited the above quote down to three points (not intending to diminish the original post!). Hope you don't mind

Here, in pictoral form, is my explanation for why the climate models are not correct (or, to be more accurate, why the climate models are not accurate):

And here is my explanation in written form: With the exception of the "Greenhouse Gases" element, which scientists believe they understand to a high level, everything else listed that contributes to positive and negative forcings is understood only to a Medium or Low level (and most of these forcings fall into the "Low" category). Even if we ignore the possibility that there may be yet other forcings of which we know nothing, what we do know we don't understand to a good enough level to start making basic predictions (or, indeed, projections).

Looking at the chart above it is easy to see that there is a distinct possibility that Aerosols by themselves could well completely negate the effects of all the other greenhouse gases combined, but we don't yet know enough about how aerosols affect the environment to make any definitive conclusions.

Since the models are programmed using data that are derived from different studies with different degrees of certainty, the models are fundamentally flawed in their ability to give meaningful output. Also, it seems quite reasonable that the best understood information will be the best programmed and that therefore the output from the models will show a high degree of bias towards the best-programmed information.

To (over-)simplify it a bit, if you tell the models that greenhouse gases increase temperature then the models will attribute temperature increases to greenhouse gases.

As for model "hindcasts", it will always be possible to find a particular set of rules that will cause a particular outcome. If more information becomes available then you need only change the rules a little bit to retain the original outcome. As you say in your post, the right outcome may have been obtained by wrongful attribution of cause and effect, which means that even though the hindcast portion of the program may yield reasonable results, it says nothing of the reliability of the forecast from the same model.

Did any of that make sense? I think I got a bit vague in the middle there somewhere...

CB

[olly aitch]

welcome to Net Wx Ollie but could we have your town in your avatar please, then we all know where any weather reports are coming from?

many tks

Sorry everybody,I'm from doncaster.Will add to avatar asap. :lol:

[johnholmes]

cheers mate

[Admiral_Bobski]

So has anyone else watched the documentary yet?

http://www.aconvenientfiction.com/

Olly's the only one who seems to have taken the time...

B)

CB

[BrickFielder]

I have not watched it but I have read the associated report. The view point seems to be that things are over exagerated with statistics to show that in many respects things are improving and co2 emissions are unlikely to rise as suggested. For me it is a little weak scientifically tending to concentrate on stastitics rather than science to back up its arguments.

Following on from my early post about outgoing long wave radiation I decided to do a little more digging to find out a bit more.The energy exchange between Earth and space is determined by the emitted heat [longwave radiation] and the reflected part of the solar irradiance [shortwave raditaion] at the top of the atmosphere . Equilibrium of Earth's climate requires that the global annual mean net radiation flux at the top of the atmosphere to be approximately zero otherwise the planet will warm or cool although not specifically at the surface.Over the tropics there has been a marked increase in outgoing long wave radiation and a decrease in outgoing short wave radiation. There have been a number of corrections to the data and plenty of discussions about the relative amounts of the changes but fundamentally there have been changes in outgoing radiation. This is important because no climate model has been able to model any changes in outgoing radiation for the last 20 years, they even fail to model the significant changes in the hadley and walker circulations successfully. Some climate scientist have estimated that the effects of these changes are ten times that of the effects of CO2 as a greenhouse gas.This led Chen to believe that global warming in recent times was mainly due to natural cycles. I don't think I would agree ,but climate models failure to model areas of increasing and decreasing cloud at various heights introduces a greater uncertainty in the models than even the IPCC would admit.

Nasa earth observatory report

Chen and radiative budget

Radiative budget modelling failures

Updated details 2006

[Admiral_Bobski]

I have not watched it but I have read the associated report. The view point seems to be that things are over exagerated with statistics to show that in many respects things are improving and co2 emissions are unlikely to rise as suggested. For me it is a little weak scientifically tending to concentrate on stastitics rather than science to back up its arguments.

Thanks for your reply - you've given me a lot more to read and digest (it's neverending, I tells ya!).

As for the documentary, it does argue the statistics mainly in terms of how the statistics have been misrepresented. There's an interesting little bit on the infamous Hockey Stick graph that's worth watching as well. I would highly recommend watching the documentary itself rather than reading the report which is, by its very nature, not a complete run-down of the presentation.

You could argue that the film is scientifically weak (a criticism that's equally valid of Al Gore's movie), but the point of arguing the statistics is, I believe, intended to highlight the fact that the science isn't actually as certain as is frequently claimed. The arguments he makes do not require science, per se, at least not new science that rebuts the accepted science - he's essentially saying that the science itself is fine insofar as it goes, but that the conclusions drawn do not necessarily follow on considering the science's relative uncertainty.

Seriously, this documentary is highly recommended.

CB

[Admiral_Bobski]

Has the debate died again? Has anyone watched the "Convenient Fiction" documentary? Has nobody got anything contentious to add?

There was an article by an astronomer the other day countering the paper which claimed that the sun isn't responsible for the current warming - I shall dig it out and either link to it (if I can find it online) or quote from it (if I can't) later on.

CB

[Admiral_Bobski]

Here's a link to the aforementioned article entitled "The Truth Is, We Can't Ignore The Sun", as printed in the Telegraph:

http://www.telegraph.co.uk/opinion/main.jh...7/15/do1508.xml

The piece is brief, lacks any real detail, but at least puts the case across that the recent paper dismissing the Sun should be re-examined. It is written by David Whitehouse, Astronomer, former BBC Science Correspondent, and author of "The Sun: A Biography".

:wacko:

CB

[Devonian]

Here's a link to the aforementioned article entitled "The Truth Is, We Can't Ignore The Sun", as printed in the Telegraph:

http://www.telegraph.co.uk/opinion/main.jh...7/15/do1508.xml

The piece is brief, lacks any real detail, but at least puts the case across that the recent paper dismissing the Sun should be re-examined. It is written by David Whitehouse, Astronomer, former BBC Science Correspondent, and author of "The Sun: A Biography".

:wacko:

CB

I think it's the kind of stuff sceptics should write. None of this 'oh, you're just religious' stuff directed at 'warmers', none of this 'it's all a fraud[or similar]' c*ap, nope, it focusses on what science always has - doubts.

"My own view on the theory that greenhouse gases are driving climate change is that it is a good working hypothesis - but, because I have studied the sun, I am not completely convinced."

So, he's not completely convinced it's not the sun. Neither am I, but I'm not completely convinced the sun wont explode tomorrow either!

Edited July 16, 2007 by Devonian

[Admiral_Bobski]

I think it's the kind of stuff sceptics should write. None of this 'oh, you're just religious' stuff directed at 'warmers', none of this 'it's all a fraud' c*ap, nope, it focusses on what science always has - doubts.

"My own view on the theory that greenhouse gases are driving climate change is that it is a good working hypothesis - but, because I have studied the sun, I am not completely convinced."

So, he's not completely convinced it's not the sun. Neither am I, but I'm not completely convinced the sun wont explode tomorrow either!

Hi Dev! I'm glad you didn't take issue with the article - I thought it seemed like one of the more reasoned and reasonable articles I've read lately from the skeptic camp, and the fact that it is written by an astronomer (who, therefore, has some knowledge of the Sun!) seemed to give it some credibility.

Notice, though, that he says that "[AGW] is a good working hypothesis". A working hypothesis is not a theory - hypothesis has more relation to speculation than fact. Hypothesis is invaluable though, as it is what theories are based on, but AGW hasn't actually made the leap from hypothesis to theory yet. (This is more than just semantics )

I think the biggest problem with the outright dismissal of the Sun is highlighted in the chart (posted earlier in the thread) of climate forcings, listed from Highest to Lowest Level of Understanding. The Sun is right at the bottom of the chart - the thing which is understood least of all. It's roughly akin to making a list of "Most Powerful Explosives" and dismissing nuclear weapons because the author doesn't understand how they work...

More later.

:wacko:

CB

EDIT - I think that when he says "I am not completely convinced" he means that he's not completely convinced by the AGW hypothesis, which is slightly different from not being completely convinced that it's not the sun...

Edited July 16, 2007 by Captain_Bobski

[Devonian]

Hi Dev! I'm glad you didn't take issue with the article - I thought it seemed like one of the more reasoned and reasonable articles I've read lately from the skeptic camp, and the fact that it is written by an astronomer (who, therefore, has some knowledge of the Sun!) seemed to give it some credibility.

Notice, though, that he says that "[AGW] is a good working hypothesis". A working hypothesis is not a theory - hypothesis has more relation to speculation than fact. Hypothesis is invaluable though, as it is what theories are based on, but AGW hasn't actually made the leap from hypothesis to theory yet. (This is more than just semantics )

I think the biggest problem with the outright dismissal of the Sun is highlighted in the chart (posted earlier in the thread) of climate forcings, listed from Highest to Lowest Level of Understanding. The Sun is right at the bottom of the chart - the thing which is understood least of all. It's roughly akin to making a list of "Most Powerful Explosives" and dismissing nuclear weapons because the author doesn't understand how they work...

More later.

:wacko:

CB

Actually, I think he accepts the figures for the sun and points out the apparent (to me) coincidence with temps. So, he accepts the warming, he accepts the solar data.

Interestingly you talk of hypothesis (I think AGW is a theory btw) and then seem to say we should blame the sun 'the thing least understood at all' - what have all these solar experts been doing . So you reject one claimed unlikely hood for another claimed unlikelyhood? Humm.

I think we know enough to put AGW as a theory, and I think we know enough about the sun (and atmosphere physics) to be pretty sure the sun isn't responsible for recent warming/warmth.

[Admiral_Bobski]

Actually, I think he accepts the figures for the sun and points out the apparent (to me) coincidence with temps. So, he accepts the warming, he accepts the solar data.

Interestingly you talk of hypothesis (I think AGW is a theory btw) and then seem to say we should blame the sun 'the thing least understood at all' - what have all these solar experts been doing :wacko: . So you reject one claimed unlikely hood for another claimed unlikelyhood? Humm.

I think we know enough to put AGW as a theory, and I think we know enough about the sun (and atmosphere physics) to be pretty sure the sun isn't responsible for recent warming/warmth.

He accepts certain figures but says that the paper rejecting the sun flies in the face of the figures. His use of the word "coincidence" is intended not as meaning "lucky chance" but rather that two sets of data "coincide" (occur at the same time), meaning that there might be a connection (hence "a connection: possibly").

I'm pretty sure that AGW is still regarded as a hypothesis and not an actual theory (I think even the IPCC refer to it as a hypothesis, but I'll double check that). I'm not saying, nor have I ever said, that we should "blame the sun" - I have simply stated that the Sun may have more to do with warming than is generally accepted, and our low level of understanding of it is precisely the reason why it shouldn't be dismissed.

I don't think we actually know enough to put AGW as theory - enough of the hypothesis seems to hang together for it to be a working hypothesis (that is, one from which a theory can be derived). I'm not sure how you can claim we know enough about the Sun to be able to disregard it, either. The scientists themselves concede that our understanding is woefully limited.

I'll be back on later...

CB

[Admiral_Bobski]

Just to throw another log on the fire, I've noticed an error in the Forcings chart posted earlier. I'll repost it here for reference:

If you notice the Net Anthropogenic Forcing is given as 1.6Wm^-2, allowing for an error margin between 0.6 and 2.4Wm^-2. The error margin should surely allow for all combinations of the data - if we were to take the positive forcings at their lowest values and the negative forcings at their highest values then we arrive at a potential Net effect of -0.547Wm^-2, which would be an overall cooling effect.

Now, obviously I'm not trying to claim that we've actually been cooling all along, but the point is the figures allow for a cooling effect with our current level of understanding of the various forcings. Is this not a sure sign that we need to study these various forcings in greater detail before drawing any conclusions?

CB

[Devonian]

Just to throw another log on the fire, I've noticed an error in the Forcings chart posted earlier. I'll repost it here for reference:

If you notice the Net Anthropogenic Forcing is given as 1.6Wm^-2, allowing for an error margin between 0.6 and 2.4Wm^-2. The error margin should surely allow for all combinations of the data - if we were to take the positive forcings at their lowest values and the negative forcings at their highest values then we arrive at a potential Net effect of -0.547Wm^-2, which would be an overall cooling effect.

Huh? It would be an odd world if that was at all likely (just like taking +ve forcings at their highest values and -ves at their lowest - also clearly not happening).

Now, obviously I'm not trying to claim that we've actually been cooling all along, but the point is the figures allow for a cooling effect with our current level of understanding of the various forcings. Is this not a sure sign that we need to study these various forcings in greater detail before drawing any conclusions?

CB

I don't think the figure do allow tbh, I suspect it breaks some statistical 'rule'. The chance of a series of most -ve negative forcings and most +ve positive forcings cases all occurring at the same time must be minimal, indeed I'd say 'ruleoutable'. I wouldn't run with it.

But, show me I'm wrong with some example of something similar?

[Admiral_Bobski]

Huh? It would be an odd world if that was at all likely (just like taking +ve forcings at their highest values and -ves at their lowest - also clearly not happening).

I don't think the figure do allow tbh, I suspect it breaks some statistical 'rule'. The chance of a series of most -ve negative forcings and most +ve positive forcings cases all occurring at the same time must be minimal, indeed I'd say 'ruleoutable'. I wouldn't run with it.

But, show me I'm wrong with some example of something similar?

The thing with statistical analysis is that it must take all eventualities into account. Whether or not the lowest +ve and highest -ve values is likely is neither here nor there - they are a part of the dataset, whether likely or not.

As I said above, I am not trying to claim that this is actually the case, nor even that it is necessarily possible, simply that the very fact that the statistics allow for it shows a significant degree of uncertainty in our understanding.

CB

[Devonian]

The thing with statistical analysis is that it must take all eventualities into account. Whether or not the lowest +ve and highest -ve values is likely is neither here nor there - they are a part of the dataset, whether likely or not.

As I said above, I am not trying to claim that this is actually the case, nor even that it is necessarily possible, simply that the very fact that the statistics allow for it shows a significant degree of uncertainty in our understanding.

CB

Hey, if you're going to take all eventualities into account then each and every day of our lives it's toooo dangerous to either stay in bed or get out

As I say I don't think either extreme of possible eventualities worth taking into account. They're NOT going to happen.

[Admiral_Bobski]

Hey, if you're going to take all eventualities into account then each and every day of our lives it's toooo dangerous to either stay in bed or get out

As I say I don't think either extreme of possible eventualities worth taking into account. They're NOT going to happen.

I am not taking all eventualities into account personally, but that doesn't mean the statistics shouldn't. A complete list of all the things that could kill you when you walk out your door should include "Being Hit By A Falling Meteor", however unlikely it may actually be to happen.

So, once again, I am not suggesting that the figures show we should or could be in a cooling trend, I am merely highlighting the fact that our lack of understanding allows for a whole range of possibilities. We shouldn't just pick the possibility that best fits a hypothesis (or theory) - we should refine our understanding, narrow those error bars down and see what possibilities are left open to us.

If you eliminate the impossible then whatever remains, no matter how improbable, must be the truth...

CB

[Devonian]

I am not taking all eventualities into account personally, but that doesn't mean the statistics shouldn't. A complete list of all the things that could kill you when you walk out your door should include "Being Hit By A Falling Meteor", however unlikely it may actually be to happen.

So, once again, I am not suggesting that the figures show we should or could be in a cooling trend, I am merely highlighting the fact that our lack of understanding allows for a whole range of possibilities. We shouldn't just pick the possibility that best fits a hypothesis (or theory) - we should refine our understanding, narrow those error bars down and see what possibilities are left open to us.

If you eliminate the impossible then whatever remains, no matter how improbable, must be the truth...

CB

Which is what the error bars do? The most likely figures are simply that.

Anybody reading your above post would think scientists in the field haven't been working away at such problems. But, equally, we should all know by now that this kind of science doesn't deal in certainties - but hey, if certainty be what you demand you can stay a sceptic for ever .