My belief in Global Warming is getting shaky

goku · July 5, 2008

i take that as a no :ohdear:

InfiniteNow · July 5, 2008

I am going to review the rest of the thread because I have not seen the solar activity thing you talked about.

You know what's funny? I was just revieing the thread, and noticed that you said the above in post #562, yet way back in post #515 I gave a reference that clearly indicated that solar is not causing the warming we have been experiencing, regardless of the mechanism invoked. I even put the part about solar in bold text. :ohdear:

You're either not reading the information being offered to you, or you are reading it and ignoring it since it conflicts with your preconceived beliefs on the topic.

With all of that said, I like that you are willing to review the rest of the thread. That is a sign of intellectual courage, and it does you much credit.

Grains · July 5, 2008

You know what's funny? I was just revieing the thread, and noticed that you said the above in post #562, yet way back in post #515 I gave a reference that clearly indicated that solar is not causing the warming we have been experiencing, regardless of the mechanism invoked. I even put the part about solar in bold text.

You're either not reading the information being offered to you, or you are reading it and ignoring it since it conflicts with your preconceived beliefs on the topic.

With all of that said, I like that you are willing to review the rest of the thread. That is a sign of intellectual courage, and it does you much credit.

I remember that post and did read it...

The problem is that most of the sources you posted did not talk much about solar and didn't relate to this article...you wrote thos responses in response to that documentary we were discussing which your articles where very helpful..and in regards to your bold text they talk from 1985 where as the article I posted talks more into the future. I will post it here in bold as well. So yes I did read your links but I was looking for more information on talking about the future of solar activity and what this scientist claims which your articles contained no information on his claim...

Astrophysics knows two solar activity cycles, of 11 and 200 years. Both are caused by changes in the radius and area of the irradiating solar surface. The latest data, obtained by Habibullah Abdusamatov, head of the Pulkovo Observatory space research laboratory, say that Earth has passed the peak of its warmer period, and a fairly cold spell will set in quite soon, by 2012. Real cold will come when solar activity reaches its minimum, by 2041, and will last for 50-60 years or even longer

It would be great to see some articles/discussion talking about the future of these solar cycles.

InfiniteNow · July 5, 2008

in regards to your bold text they talk from 1985 where as the article I posted talks more into the future. I will post it here in bold as well.

<...>

Astrophysics knows two solar activity cycles, of 11 and 200 years. Both are caused by changes in the radius and area of the irradiating solar surface. The latest data, obtained by Habibullah Abdusamatov, head of the Pulkovo Observatory space research laboratory, say that Earth has passed the peak of its warmer period, and a fairly cold spell will set in quite soon, by 2012. Real cold will come when solar activity reaches its minimum, by 2041, and will last for 50-60 years or even longer

It would be great to see some articles/discussion talking about the future of these solar cycles.

That came from this link:

RIA Novosti - Opinion & analysis - A cold spell soon to replace global warming

It's in the "Opinion and Analysis" section of a Russian news site. Do you have something peer-reviewed? Any idiot can make a webpage and make a bunch of claims. What you need to share for your idea to be taken seriously is an idea which has withstood the gauntlet which is peer-review.

(btw... on quick glance, that article is littered with falsehoods, and much of the crap he says in that article is flat out wrong).

InfiniteNow · July 6, 2008

In sum, I understand the points you are making, but I disagree with the conclusions you have drawn from them. You seem convinced that since climate is a complex system it's not possible for us to make models which work. I say, we'll never be perfect, but we're really close, and we get closer each day.

Thinking some more on this issue, I wanted to make something clear which may be missed by people out there who are still trying to wrap their heads around this modelling discussion.

Models don't predict the future.

They are not crystal balls. They are not strangely dressed stinky people at the carnival. They are not palm readers or tarot card sorters or tea leaf smokers.

No. That's not what they do.

They provide an accurate set of outputs given a set of inputs. They don't predict the future, they model it.

So, the models can tell us:

IF humanity does this₁, THEN that₁ will happen.

IF humanity does this₂, THEN that₂ will happen.

IF humanity does this₃, THEN that₃ will happen.

IF humanity does this_...n, THEN that_...n will happen.

Models cannot predict human behavior. We don't know what political changes will alter society and how we operate (which I think is closer to the point Overdog is making), however, models DO provide a series of if/then conditions. When those conditions are met, the models are extremely potent.

With modelling, we actually know much more than "just what will happen in the future." We actually know and gain visibility into the rich and expansive landscape of what might happen in the future if the actions of humans change. It's really very powerful.

So, if we double the amount of CO₂ we add to the atmosphere, then temperature will change this much.

If we triple the the amount of CO₂ we add to the atmosphere, then temperature will change that much.

If we reduce the amount of CO₂ we add to the atmosphere by half, then temperature will change this much...

I just thought that was worth mentioning, and may not have been clear earlier.

Models don't predict the future, they model it, and they run various scenarios as inputs to get a clear picture of what will happen if humanity continues with the status quo or makes some sort of changes (for better or worse)... and they do so with awe inspiring accuracy.

REASON · July 6, 2008

I think that's a very important aspect of scientific modeling to consider. :ohdear:

Overdog · July 6, 2008

First, let me say that I think we are quite close to being on the same page. I have read the links you posted. I do not dispute that the models are very good at projecting temperature trends over time for a given set of inputs.

As Modest has pointed out, Excell is quite good at this, too.

I can see how the tone of my previous posts may have led you to this conclusion, but I do not think I have misunderstood you. However, to be sure, I will summarize below my understanding of your points so we can see if I am accurate in my understanding.

Climate systems are enormously complex, and have hundreds of variables to consider

Models use different programs to achieve their results (the maths are not consistent from model to model)

Models are often adjusted manually, hence introducing another source of potential error

The across-model outputs are not always aligned

Climate is a chaotic system

Is this a fair assessment? If not, please let me know if I've misrepresented or misunderstood you and we can correct that relatively simply.

It's a pretty fair assesment. There is one point however, where we may see things differently, and that is the first one.

"Climate systems are enormously complex, and have hundreds of variables to consider"

The basis of my general critisism is that we don't know how many variables there are to consider. Worse, we don't know how many we don't know.

Well, almost. Climate and weather are, in fact, the two most common examples of chaotic systems since they evolve with time and are highly dependent on initial conditions. I think we both agree that it's fair to suggest that these models have many parallels and characteristics of a mathematically defined dynamic/chaotic system.

The bigger point, in my view anyway, is the distinction between modelling weather versus modelling climate.

As my analogy about the waves on the beach in a former post alluded to, it's much simpler to predict trends accurately over long expanses of time than specific and individual moments or weather events. I may not be able to tell you exactly where on the wall the next incoming wave will hit, but I can tell you the average on that wall that the waves will hit throughout the coming year with enormous validity.

This is how we model climate. We are talking about global yearly averages, not what the weather will be like on Thursday, November 27 at 3:42PM Central time in Waupeton, Iowa.

This is why a little bit of error in those initial conditions is less worrisome. Is there noise? Yes, absolutely. I concede that, and I'd either be a liar or really stupid if I tried to suggest that models are perfect (and, I don't classify myself as either of those things). However, that noise is reduced rather significantly by modelling the data over years instead of exact moments and locations, especially since the accuracy of our inputs gets better all of the time.

I think we are in agreement here.

...First, I want you to remember that the data we have is being improved and of increasing accuracy every single day...

Agreed, a point that is central to my critisism.

Second, we DO know the conditions which have the greatest impact...

We do? That statement does not seem to be completely consistent with the previous one, or with the one below.

New factors popping up is EXACTLY what we want, as they only make the models better. This is NOT a bad thing. Also, there are scores of people working on those subjects which you have classified "not well understood," so we'll have that information available very soon.

Really? How long do think we will have to wait?

But here's the rub. The more we learn, and the more we add new information to our models, and the better we understand all of the various factors and variables, the more our predictions are confirmed!

That's the key point in my book.

I would say here that the more we learn, and the more we add new information to our models, and the better we understand all of the various factors and variables, that the margins of error in the projections may be reduced, but your link Climate is too complex for accurate predictions - earth - 25 October 2007 - New Scientist Environment seems to dispute even that.

I do not see how you can say our predictions are confirmed by "learning more" and by a better understanding of "the various factors and variables".

The more we learn and the better we get, the more we confirm the past predictions. The past predictions have been amazingly accurate (especially considering the mathematical issues with modelling chaotic/complex systems to which you've been alluding). Our predictions are only getting better, and we have without fail confirmed with all of this new information that the future is getting warmer.

Again, I don't dispute that climate models have shown a remarkable degree of accuracy with respect to some limited aspects of past climate, but as I have said, although it is a necessary condition, it is not sufficient.

I get the sense then that no model will ever be good enough for you.

Well, I admit I do have a healthy scepticism of prophecy, whatever its form.

That does not not mean that no model will ever be good enough for me, though. As a sailor, I depend on weather predictions a great deal, I regularly risk my life depending on them. But one thing I have learned is that while statistically I am better off with the weather predictions, I have on a number of occasions found them to be frighteningly wrong.

I doubt that I will ever accord more than some arbitrary degree of confidence to weather predictions. The degree of confidence I accord to any particular weather prediction is literally a judgement call I make every time I get underway.

You are approaching this with your mind made up that climate is too complex to model.

Yes, I certainly am. That is why is called a "Chaotic" system. I think is is important to distinguish between modeling "Climate" and projecting trends in temperature. Projecting trends in temperature is essentially what these climate models are focused on doing. I think we both agree on this.

Would you agree that it ultimately boils down to projecting the degree to which this chaotic system is going to be Endothermic or Exothermic in the future? And would you agree that some unknown number of initial conditions, and some number of unknown or poorly understood factors are all dynamically interacting to determing whether it is going to be one or the other?

And with so much new information popping up every day, a point we both agree on, the degree to which one can feel justified in according credibility to the projections seems at this point to be just a matter of opinion, does it not?

I have shown how accurately they represent past climate as a way to show their validity, and you reject that.

Yes, and you have not shown why those reasons are not legitimate.

Well, they have also accurately predicted the degree of warming over the past decade. Way back when the models were still "in their infancy," they STILL got it really damn close.

Now this is exactly what I'm looking for. Projections confirmed by hard evidence. I have not seen the one you are refering too. It's the one I've been asking for. Which model or models, prior to or even during 1998 predicted the decline in the last decade we have been discussing?

This would constitute a data point of the kind of hard evidence I'm looking for. And when we have three of them we will have enough to begin to distinguish accuracy from mere coincidence. Again, matches to a pre-existing trend is not particular convincing.

In sum, I understand the points you are making, but I disagree with the conclusions you have drawn from them. You seem convinced that since climate is a complex system it's not possible for us to make models which work.

I'm distinguishing between a system that is merely complex, and one that is Chaotic, this is a significant distinction.

I say, we'll never be perfect, but we're really close, and we get closer each day.

The part I have a problem with is the part that says we're really close. How can you know how close we are. Can you be more specific?

In sum, I think what we have is a legitimate difference of opinion as to the degree of credibility climate models currently merit, and the criteria for determining what that degree of credibility should be.

InfiniteNow · July 6, 2008

Second, we DO know the conditions which have the greatest impact...

We do?

See… now you’re moving the goal posts. You were challenging the models, and I responded to that. Now you are challenging our understanding of climate systems in general, and our ability to accurately record the features of those systems.

Yes, we DO know the conditions which have the greatest impact on our climate, and we ALSO know with great accuracy the present levels of those conditions due to decades of measurements and refinements there as well.

So, which is it? Is it that the models are wrong or that we don’t know what conditions have the greatest impact on climate? If you’re going to move the goal posts, then at least be clear about what you are asking.

You are approaching this with your mind made up that climate is too complex to model.

Yes, I certainly am.

Well, that’s unfortunate, and there aren’t a whole lot of arguments I can make to move you away from such a conclusion. I’ve already shown how well the models work, I’ve shown how much they’ve improved, and I’ve shown how powerful of a tool they can be. I’ll rest my case there, and let you go on with your preconceived notions intact.

Would you agree that it ultimately boils down to projecting the degree to which this chaotic system is going to be Endothermic or Exothermic in the future? And would you agree that some unknown number of initial conditions, and some number of unknown or poorly understood factors are all dynamically interacting to determing whether it is going to be one or the other?

Not really, no. I think it boils down to what behaviors human engage in over these next several years. If we could pin down details on that information, and predict the exact characteristics of human behavior, then the models would show us with great clarity and accuracy what would happen. The only piece that is really beyond our reach is knowledge of how society will behave and how humans will change their behaviors.

Since the models work so well already, and are also improving, “unknown factors” are not exactly my biggest area of concern. If “unknown factors” were the problem you suggest they are, then this would be apparent in the models output and reconstruction of past climates, and model performances during recent decades.

Which model or models, prior to or even during 1998 predicted the decline in the last decade we have been discussing?

This would constitute a data point of the kind of hard evidence I'm looking for. And when we have three of them we will have enough to begin to distinguish accuracy from mere coincidence.

I already responded to this previously. There is no downward trend. Look again at Modest’s graph. It’s limited to one decade and is very nearly flat. While we’re certainly heading in this direction, models don’t have to be able to reflect every tiny blip of data to get the overall output correct.

Looking at the data for more than one decade that doesn't arbitrarily set the starting point during an abnormally warm year clearly vindicates the outputs of the models, and shows that the models have been quite accurate.

Again, I reject the premise of your question since the climate is not cooling.

In sum, I think what we have is a legitimate difference of opinion as to the degree of credibility climate models currently merit, and the criteria for determining what that degree of credibility should be.

Well, then I suggest you respond to my original inquiry and start here:

Links to climate models and/or climate modeling groups

You need to find a specific model, show it’s margin of error, and also how predominantly that one model among many is used in the field when doing this work and forming conclusions.

Until then, you’re still just waving your hands about and expecting us to take you seriously.

Handwaving - Wikipedia, the free encyclopedia

modest · July 6, 2008

I already responded to this previously. There is no downward trend. Look again at Modest’s graph. It’s limited to one decade and is very nearly flat. While we’re certainly heading in this direction, models don’t have to be able to reflect every tiny blip of data to get the overall output correct.

One small qualification that comes with this trend:

This is flat - completely flat - at least, I can't tell which way it's sloping. But, this is not the logarithmic trend line that has a curved line. That one slopes down to the very perceptive eye. The one depicted above is a straight line or linear trend and it comes out flat or level. This is not biased in any way - it's just a trend choice in Excel. The linear choice comes out completely flat and the logarithmic choice comes out ever so slightly angled down (and obviously curved).

Considering this thread, I'm sure there is a lot of fighting room in that, so let me stress one more time: this is just a choice of kinds of trendlines. There is no bias either way. Nevertheless, I think it's important to point this out as explicitly as possible considering what I had to go through to even get Grains to admit excel was making trends rather than averages. I think to be as descriptive and honest with this as possible is good.

I said this when I originally posted that pic, but I did not very clearly explicate in a way that would avoid future complications :eek_big: which I think I've now done.

Unfortunately this leave us in a position where both these statements are true:

The last 10 years show no increase or decrease in temp
The last 10 years show a decreasing temperature

Oh boy :)

~modest

Overdog · July 6, 2008

Until then, you’re still just waving your hands about and expecting us to take you seriously.

No, I have posted what I believe are legitimate reason's for questioning the the accuracy of the Climate models, and you have simply ignored them. You have not countered them. You have not shot them down. You haven't even tried.

In one breath you acknowledge that we are still discovering conditions which have impact on our climate, yet in the next you claim we DO know the conditions which have the greatest impact on our climate. How can you make that claim?

Until you answer the questions and address the issues I have raised , it is you who are just waving your hands and expecting to be taken seriously.

Overdog · July 6, 2008

So, in post 570, I posted the following:

Grassl (2000) lists four capabilities of a credible coupled general circulation model:

"Adequate representation of the present climate.
"Reproduction (within typical interannual and decades time-scale climate variability) of the changes since the start of the instrumental record for a given history of external forcing;
"Reproduction of a different climate episode in the past as derived from paleoclimate records for given estimates of the history of external forcing; and
"Successful simulation of the gross features of an abrupt climate change event from the past."

McAvaney et al. (2001) compared the oceanic component of twenty-four coupled models, including models with and without flux adjustments. They found substantial differences among the models. For example, only five models calculated a meridional overturning circulation within 10% the observed value of 20 Sv. Some had values as low as 3 Sv, others had values as large as 36 Sv. Most models could not calculate a realistic transport for the Antarctic Circumpolar Current.

Grassl (2000) found four years later that many models, including models with and without flux adjustment, meet the first criterion. Some models meet the second criterion, but external solar forcing is still not well known and more work is needed. And a few models are starting to reproduce some aspects of the warm event of 6,000 years ago.

But how useful are these models in making projections of future climate? Opinion is polarized. At one extreme are those who take the model results as gospel. At the other are those who denigrate results simply because they distrust models, or on the grounds that the model performance is obviously wrong in some respects or that a process is not adequately included. The truth lies in between. All models are of course wrong because, by design, they depict a simplified view of the system being modeled. Nevertheless, many - but not all - models are very useful.
From Trenberth (1997).

This has not been adressed or refuted. I therefore still contend there is legitimate reason for questioning the accuracy of climate models.

I do not claim that the models are not useful, merely that at this point, until either Grassl's criteria are discredited or the models meet all four conditions, there is no real basis for assessing the accuracy of the models without at least three data points based on observation, observations that are something other than a projection of a pre-existing trend.

This means that the best we can do, as is stated in other links I have provided, is "reasonably assume they are accurate" for some limited span of time into the future.

"Reasonably assume" are the key words here, and are the reason that I assert that the degree to which we assign credibility to the models is open to debate, and remain a matter of opinion.

InfiniteNow · July 6, 2008

Name a speicific model with these accuracy issues to which you are alluding so we can be specific.

Overdog · July 6, 2008

Name a speicific model with these accuracy issues to which you are alluding so we can be specific.

Come on, dude, stop trying to avoid the issue. You are the one who accused me of academic dishonesty...address the issues I have raised or bug out.

Zythryn · July 6, 2008

Infi, previously Overdog said 'any of them'.

So if you can find any one that counters his argument, I would think he would then give up his position, right Overdog?

Overdog · July 6, 2008

Infi, previously Overdog said 'any of them'.
So if you can find any one that counters his argument, I would think he would then give up his position, right Overdog?

Well, I might accord greater credibility, but to be convinced that it is not a matter of opinion, which is my main point, I need Grassl's criteria to be refuted, or see evidence that all four criteria have been met. I will also settle for a minimum of three data points of accurately predicted future projections which are not merely projections of an existing trend.

Zythryn · July 6, 2008

So will one model that meets your stipulation be sufficient, or do you need more?

As a more basic question, if the models have a 'reasonable assumption' of being "true" is that not reason to support throwing less CO2 into the air?

I agree with you (as does just about everyone here I think) that more accuracy is desireable.

As for the reason we can be confident that we understand the impact of the biggest factors, I think that comes from the fact that when we backtest models they are very accurate. If we didn't understand the major factors, the backtesting would not be nearly as close.

InfiniteNow · July 6, 2008

Performance metrics for climate models

(http://www.atmos-chem-phys-discuss.net/8/10873/2008/acpd-8-10873-2008-print.pdf)

http://ams.allenpress.com/perlserv/?request=res-loc&uri=urn%3Aap%3Apdf%3Adoi%3A10.1175%2FBAMS-89-3-303

http://www.atmos-chem-phys-discuss.net/8/10873/2008/acpd-8-10873-2008.pdf

I also advise the reference sections of each.

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