Accuracy of An Inconvenient Truth

[SkepticLance]

That's the urban heat island argument. You may want to read the RealClimate article on that point:

 

http://www.realclimate.org/index.php/archives/2004/12/the-surface-temperature-record-and-the-urban-heat-island/

 

Bottom line' date=' the UHI effect is negligable.

 

 

 

Why is that more likely?

 

Where's the study?

 

Who peer reviewed it?

 

 

 

To pound the point into your head again: [i']CO₂ isn't the only forcing affecting the climate system[/i]

 

 

 

No, it doesn't. It means other forcings beyond CO₂ affect the climate system.

 

bascule.

I said that the urban heat argument may or may not be correct. Whichever really does not matter. The point is that Mann used an improper technique to get his results, and others have achieved different results using a more scientifically sound approach. I am reluctant to reveal the dendrochronology study here since I am still in my debate with herpguy and want to use it there.

 

One source of error in all these arguments is data selection (I am just as guilty as you). We tend to use data that supports our viewpoint. Temperature increase over the 20th Century has been measured in many different ways and many different sets of results have been obtained. By selecting the set we prefer, we skew the argument. We should all be aware that there are many different possible graphs of temperature rise.

 

Another data set is the study of 169 glaciers with average shrinkage measured showing a nearly linear melting from 1810 to 2000. The world is warming up, and the hockey stick shows a drastic spike to tie in with greenhouse gas theories. However, some of the other sets of data do not show this at all, including glacier meltings. bascule, as I have always said, you may be right. However, you may be quite wrong. The doubts and uncertainties in this whole issue are too great.

 

bascule, you have gone quite funny in your response to my comments on your temperature/carbon dioxide graph over the past 500,000 years. Your original point was that this showed carbon dioxide driving temperature. I have shown that the reverse applies. You now appear to be arguing something else entirely. Do you now agree that your graph does not prove your original point?

[swansont]

swansont said :

 

These statements appear to assume some linear relationship' date=' even though it has been recognized elsewhere that the behavior of the climate is very nonlinear and complicated. It is incorrect to assume that a small change in conditions can't lead to a large effect. [/i']

 

If global warming is caused, predominantly, by anthropogenic greenhouse gases, then the increase in greenhouse gases will precede increase in temperature, and the two patterns will be similar. They do not have to be identical, but similar. Your argument does not obviate this basic rule.

 

 

That's because there is no such rule. I can, for example, take a shut-down nuclear reactor and increase the neutron concentration by many orders of magnitude and see essentially no change in power. Yet if I change it by a small fraction when the reactor is critical and operating at power, I get a huge change in power. The function relating the two isn't linear.

 

Climate is a nonlinear system, and there are many parameters. Conclusions drawn from a flawed premise are invalid.

[swansont]

Your comment about nuclear weapons is not relevent. Computer models were not used in the design of nuclear weapons until they had been proved to work, empirically. In other words, the modellers used their computer programs to simulate known weapons designs, and found they could achieve the results that were seen in the real world. This has not yet happened with global warming computer models. As witness the simple fact that no computer model has yet accurately modelled the pattern of the last 100 or 200 years.

 

 

This is flat-out wrong, too. Plenty of computation went into the design of the first atomic devices, before they were tested. They built a theoretical model based on smaller-scale experiments they could conduct, predicted behavior of the larger system, and then built the devices. That's science at work. Similar stuff happens all the time.

[doG]

I wonder, was the global warming of the Jurassic period caused by man as well?

[Dr. Dalek]

I wonder, was the global warming of the Jurassic period caused by man as well?

Thank you!

[bascule]

I wonder, was the global warming of the Jurassic period caused by man as well?

 

Well, that's the last word in the "debate" for me. Past climate change was natural, therefore present climate change is natural.

 

Flawless specious reasoning!

[doG]

Past climate change was natural, therefore present climate change is natural.

Hey, I'm just asking. Sea levels were higher then and there were no polar ice caps. Could any of the causes then be causes now? Does solar variation have anything to do with it? It seems a leap of faith to me to blame it all on man. Maybe someone could turn this into a new religion like L. Ron Hubbard did with dianetics and make so tax free money off of it.

[bascule]

Hey, I'm just asking. Sea levels were higher then and there were no polar ice caps. Could any of the causes then be causes now?

 

Of course natural forcings still affect the Earth's radiative imbalance. However, at the present time anthropogenically induced forcings are predominant.

 

Does solar variation have anything to do with it?

 

Yes, as I answered earlier, increased solar luminosity furthered a warming trend in the early part of the 20th century. This was a coupled with a decrease in naturally occuring reflective sulfate aerosols from volcanic emissions, due to decreased volcanic activity.

 

It seems a leap of faith to me to blame it all on man. Maybe someone could turn this into a new religion like L. Ron Hubbard did with dianetics and make so tax free money off of it.

 

So your argument is all climate science research to date is wrong.

 

What's the scientific basis for that argument?

[doG]

So your argument is all climate science research to date is wrong.

Please quote where I said that. I think if you look again you will see that I said, "It seems a leap of faith to blame it all on man". Man contributes but there is no conclusive evidence that man is the predominate cause.

[bascule]

Please quote where I said that. I think if you look again you will see that I said, "It seems a leap of faith to blame it all[/b'] on man".

 

So it's a strawman then. No one is saying that man is the only cause.

 

Man contributes but there is no conclusive evidence that man is the predominate cause.

 

Yes, there is... please review the NRC report and the IPCC report I linked earlier in the thread.

[SkepticLance]

bascule said.

 

Yes, there is... please review the NRC report and the IPCC report I linked earlier in the thread

 

bascule,

I am sorry. But neither graph you posted represents conclusive evidence. The graph on thermal forcings is the result of various calculations, and those are based on a series of assumptions that may, or may not be correct.

 

The graph on temperature versus carbon dioxide levels over the past 500,000 years implies that warming comes first and that this warming causes carbon dioxide rise, not the reverse. I am not saying that this is true for the last 100 years. However, you need to be careful of the evidence you present.

[bascule]

All right, this time I mean it, I'm done. Those of you who want to ignore climate science research or pretend it's unscientific, go right ahead. I won't stop you. But that's all you're doing: ignoring science. That puts you in the same camp as creationists.

[doG]

But that's all you're doing: ignoring science[/i']. That puts you in the same camp as creationists.

Those which draw conclusions from assumptions are ignoring science. Science doesn't draw conclusions without conclusive proof!

[swansont]

Those which draw conclusions from assumptions are ignoring science. Science doesn't draw conclusions without conclusive proof!

 

Without defining what you think constitutes "conclusive proof," the statement is meaningless.

 

The problem is in whether there has been a redefinition of what meets the standard of "conclusive proof" as science is not deductive. There is always uncertainty in scientific data, and one political ploy is to exploit that uncertainty. It is very easy to say, "I'm not convinced yet" but that really isn't enough, because the reason for this could be a misunderstanding of the science or what the data is representing, or unreasonable expectations of what data should be available. We've seen examples in this thread.

 

One could be so contrary (or intellectually dishonest) as to say that gravity hasn't been proven conclusively. I don't think anyone would back that up by jumping off a cliff, but since science isn't proven as in a deductive mathematical proof, it depends on how much data you want collected before you agree that the conclusion is warranted. And it's far too easy to say, "No, that's not enough."

[SkepticLance]

Swansont.

We all know there is no such thing as conclusive proof, and we are not asking for it. What we need is convincing evidence. That evidence, by the most basic standards of good science, must be empirical. That is, from experiments and observations in the real world.

 

What is NOT empirical evidence is processes of logic, calculations, and models. Sadly, that appears to be the main evidence supplied. Empirical evidence is rare.

 

If the 'hockey stick' graph could be shown, beyond any reasonable doubt, to be correct, that would be sufficient evidence for me. However, it was derived from improper scientific technique (a change in measurement technique mid-study) and does not agree with at least two other sets of real data I have seen.

[DrCloud]

Although our colleague from New Zealand has undoubtedly undertaken an exhaustive review of the Mann et al. temperature reconstructions to reach his conclusions, these conclusions are at some variance with those of the US National Academy of Sciences as discussed at length in this recent report. HPH

[SkepticLance]

Dr. Cloud.

I tried to download your recent report, without success.

However, I suspect it is merely a variation on what bascule has tried to put up as evidence. ie. The results of assorted acts of logic, calculations, and models.

 

These can be interpreted widely. Global climate models spew out all sorts of different predictions, depending on which assumptions are fed in at the front end. We are all familiar with these, predictions ranging from 2 Deg Celsius to about 12 degrees over the next 100 years.

 

Let me throw you a bone. I demand proper, scientific empirical evidence. This type of evidence is based on the prediction principle. Dr. Carl Sagan said it best : "The core of science is prediction."

 

This means that any scientific idea (hypothesis) has to be tested using predictive testing. You take the hypothesis and say, "If my hypothesis is correct, then I make the following novel prediction...."

 

Then you run a test to see if the prediction comes true.

 

The hypothesis we are dealing with is that global warming is caused by human activity, being an increase in greenhouse gases in the atmosphere. And I have accepted that most of the increase in greenhouse gases since 1910 is human caused. It is possible to make predictions. One such, half way successful, prediction is to say that, if greenhouse gases are increasing the insulating power of the lower atmosphere, we will see the greatest increase in temperature in areas that are very dry. Two such areas are high northern latitudes (Siberia, Canada, and Alaska), and the Sahara Desert.

 

In fact this prediction has been demonstrated, mostly, to be true. The exception is the driest continent on Earth - Antarctica, most of which is actually cooling down.

 

Conclusion; some of the global warming is actually caused by anthropogenic greenhouse gases. Is this the dominant cause? Debatable. The results are mixed.

 

I hope, however, Dr. Cloud and Swansont (and bascule if you are still reading) that this will give you an idea of what is meant by empirical evidence.

[DrCloud]

it has been typical of the approach of the climate skeptics -- both professional and amateur -- to deny the existence of both relevant data and informed analyses that do not support their positions of denial. In this case, perhaps we should be charitable and allow the possibility that internet connections to New Zealand somehow do not provide links to the National Academy of Sciences site here in the US.

 

I assure other readers that the link in my previous post works just fine and allows interested parties access to the definitive report on the Mann et al. "hockey stick" temperature curve.

 

Given the previous post, I have no further use for this particular thread or any other involving that individual. HPH

[swansont]

These can be interpreted widely. Global climate models spew out all sorts of different predictions' date=' depending on which assumptions are fed in at the front end. We are all familiar with these, predictions ranging from 2 Deg Celsius to about 12 degrees over the next 100 years.

 

Let me throw you a bone. I demand proper, scientific empirical evidence. This type of evidence is based on the prediction principle. Dr. Carl Sagan said it best : "The core of science is prediction."

 

This means that any scientific idea (hypothesis) has to be tested using predictive testing. You take the hypothesis and say, "If my hypothesis is correct, then I make the following novel prediction...."

 

Then you run a test to see if the prediction comes true.

[/quote']

 

 

But you have also previously demanded "no computer models" which is how you make the predictions in the first place!

 

In complex systems, in the cases where you can't simply recreate the system, you have to do it differently. Take, for example, cosmology. We can't recreate a star in the lab and run tests on it. Your demands would imply that we can't investigate these phenomenon scientifically. But what we can do is look at specific reactions involved, model them and run experiments to determine, e.g. specific interaction cross-sections. As you determine the parameters more precisely, your model becomes better. Do you believe that we have no understanding of how the sun works, despite not being able to make one ourselves?

 

What you are demanding is that a paricular set of methodologies be used, even when they are inappropriate to the task. bascule was right; this is the same kind of attack used by creationists. It points to a lack of appreciation of the different ways scientific analysis happens. (or, as in the case of creationism, it often means blatant intellectual dishonesty)

 

 

A predictive model uses a range of parameters because it's predicting future events, and some of the input data are uncertain. If you don't know (or can't know) a parameter exactly, you use best-estimate, best-case and worst-case values, and get a range of answers. e.g. we don't know how much CO₂ will be introduced to the environment in the future, so you extrapolate and use a range of values, and you will necessarily get a range of answers. We don't know when there are going to be other events, like volcanic eruptions. To point to that as a weakness or flaw in the science either means you don't understand the purpose of modeling or are being intellectually dishonest (like when the best and conservative estimates are eliminated, and only the worst-case estimate is presented as the prediction of the climate model). I don't see a third option.

[doG]

Without defining what you think constitutes "conclusive proof," the statement is meaningless.

Conclusive proof on this topic would be proof that is sufficient to show without doubt that the amount of global warming predominately caused by man's actions is greater than all other causes combined. I do not believe we can show that man's contributions are greater than any caused by solar variation. The Earyth has gone through many cycles from global tropical temperatures to global ice ages without man. To conclude at this point that the current warming cycle must be predominately caused by man is not science IMO.

[Dr. Dalek]

But that's all you're doing: ignoring science[/i']. That puts you in the same camp as creationists.

You're ignoring science!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Everyone has explained to you how your data is based on estimations and theory rather than reality and you ignore it and demand more!!!!!

 

it has been typical of the approach of the climate skeptics -- both professional and amateur -- ..........Given the previous post, I have no further use for this particular thread or any other involving that individual. HPH

Just like Bascule when things get too hot, he dives out. I have access to the report and will read it, but I anticipate SkepticLance is right.

[ecoli]

Your[/i'] ignoring science!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

if you were trying to correct his spelling, you got it wrong. It is 'you're'

[bascule]

Well, if people are going to troll me back into the argument...

 

You're ignoring science!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Everyone has explained to you how your data is based on estimations and theory rather than reality and you ignore it and demand more!!!!!

 

Everyone being... you and SkepticLance? Funny how the professional scientists here don't see it that way...

 

Just like Bascule when things get too hot' date=' he dives out.[/quote']

 

No, I just got tired of going in circles. It's the same tired argumentation pattern you can have with a creationist. Despite overwhelming evidence of evolution and human common ancestry with apes, a creationist will continue to insist that the evidence to date isn't comprehensive or "empirical" enough to warrant that conclusion.

 

I suspect it is merely a variation on what bascule has tried to put up as evidence. ie. The results of assorted acts of logic, calculations, and models.

 

Logic, calculations, and models are the bread and butter of science. Science is about building empirically-derived arguments using logic, calculations, and models. SkepticLance simply wants to ignore the entire argumentation process of climate science, look at the evidence for himself, and come to his own conclusions, ignoring the logic, calculation, and models of climate scientists worldwide.

[swansont]

Conclusive proof on this topic would be proof that is sufficient to show without doubt...

 

 

Sorry, but there is no science is up to that standard. There is always uncertainty, there is always the possibility of some new phenomenon, as yet undiscovered.

[SkepticLance]

Swansont said :

 

A predictive model uses a range of parameters because it's predicting future events, and some of the input data are uncertain. If you don't know (or can't know) a parameter exactly, you use best-estimate, best-case and worst-case values, and get a range of answers. e.g. we don't know how much CO2 will be introduced to the environment in the future, so you extrapolate and use a range of values, and you will necessarily get a range of answers. We don't know when there are going to be other events, like volcanic eruptions. To point to that as a weakness or flaw in the science either means you don't understand the purpose of modeling or are being intellectually dishonest

 

 

Swansont.

I have to assume I am simply not getting a message across. I am trying to get back to basics. I am not denigrating computer models, which can be useful scientific tools, not am I asking for conclusive proof. No such thing exists. I am just asking for the normal process of basic science.

 

This is :

 

Start with a hypothesis such as " Global warming is caused solely or at least predominantly by human release of greenhouse gases, and will lead the world into a catastrophic warming."

 

Any scientific hypothesis must be able to generate testable predictions. If it does not, it is worthless. As witness superstring theory, which is (so far) no more than a useless mathematical exercise. Fortunately, the hypothesis above does permit testable predictions. I already gave one example in my previous post.

 

The problem is that, when these predictions are put to the test, they give equivocal results. All I am asking from you is proper empirical evidence that is convincing enough to make the hypothesis probable.

 

I have just begun to read an excellent book. Professor Patrick Michaels, Climate scientist at the University of Virginia is critically looking at the current global warming ideas in a book called "Meltdown." I think Dr. Cloud, bascule, and Swansont should get a copy and read it. Might cut a bit of their certainty down to size.

 

Professor Michaels shows that global warming from 1750 to 1980 follows very closely the pattern of sunspots. He demonstrates from hard data that the global warming prior to 1980 has little if anything to do with greenhouse gases or human activity. He also believes that the warming from 1980 to 1998 is due to a blend of increased solar activity and human activity. (Sunspot activity reached a peak in the late 1990's). He quotes a report which studies the various IPCC scenarios, and shows that the most likely warming over the next 50 years will be no more than 0.75 Deg. Celsius - hardly catastrophic!

 

Professor Michaels has worked with the IPCC and is painfully aware that most of the people there, including those who release reports to the media, are not scientists. The organisation has a majority of politicians and bureaucrats. It appears that some, if not most, of the IPCC reports are not endorsed by the majority of IPCC scientists. This has resulted in an exaggerated view of global warming being presented to the public.

 

Let me finish by repeating, once more, my views of global warming, so that if you attack them, you are at least attacking the right target.

1. No-one yet knows the full picture. Doubt and uncertainty are rife.

2. The causes of global warming are more than one.

3. I accept that human activity is one factor, but I do not think it has been proved for a moment that it is the dominant one.

4. Catastrophist predictions are exaggerated and unlikely to happen.