Man Made Global Warming

[marksman]

There is a 0.6 degC warming from 1910 to 1940 that is not explained by the models. Therefore, it is not reasonable to claim that the GHGs are likely the cause of the warming from 1960. The only claim that can be made is that the warming from 1960 can be plausibly explained by GHGs. Any statement with more certainty than that is not supported by the evidence.

There is no reason to believe the models were not tuned to produce a result that conformed to the hypotheses preferred by the modellers. There are simply too many unknown parameters for them to do anything else.

In any case, it comes down to trust. The fiasco over the Mann hockey stick demonstrates that the IPCC and many influential climate scientists cannot be trusted. Nor am I absolutely certain that I can trust skeptical scientists like Spencer either. But I can look at the data and the arguments and the data is tells me that the actual warming has been consistently less than what the models predict and it clear that the IPCC has choosen to ignore a number of plausible explainations for the warming that would result in lower than expected warming. The trends may reverse in a few years and I will adjust my opinion accordingly. Until then, I think it is irresponsible to make policy decisions that would make no sense if the entire CO2 scare turns out to be nothing.

It's clear there's not much point in continuing the discussion. You argue that models can't be trusted because they've been tuned to match historical data. Then you argue that models can't be trusted because they don't match historical data closely enough. You don't trust any of the climate scientists looked at by the IPCC because of one scientist the IPCC looked at. Even though you've said you support many of the policy decisions that'd be taken to reduce climate change you're basically saying that we shouldn't take those decisions until we wait to see if the human caused climate change people are right. You had different reasons for supporting those policies but they're the same policies despite that.

[marksman]

Does anyone remember in the 1970's how we were supposedly headed towards a new Ice Age? Remember all the scientists who were backing that theory up?

I don't have an opinion on whether or not global warming is happening and whether or not it's caused by man.

What I do know, however, is that both sides have come up with nothing but highly disputable evidence.

Anyone who says, "Global Warming is happening and there can be no doubt about it." is full of shit.

Anyone who says the opposite is also full of shit.

We don't know yet and we have no proof yet.

If you judged by press reports then the ice age comment is valid but at the time I don't think the scientific community was anywhere close to agreeing that's what was happening. It's like what is happening now a press article will cite 2 scientists with opposing views even though there may be 10 scientists supporting 1 view and only the 1 scientist on the other side.

It's not that there's no doubt about global warming it's that based on what we know so far and most of the work done it's probably that humans are causing global warming.

[Riverwind]

I would have let you have the last word, however, you always completely misrepresent my arguments by taking them out of context or by simply ignoring the more detailed explanations.

You argue that models can't be trusted because they've been tuned to match historical data. Then you argue that models can't be trusted because they don't match historical data closely enough.

The IPCC makes the claim that the warming from 1960 is most likely due to GHGs because the models match the temperature trend *during that period* only if the GHGs are included. My argument is the certainty claimed by the IPCC is completely unjustified because:

1) We cannot know whether the match from 1960 was the result of correct theory or model tuning.

2) The models cannot reproduce the temperature trends from earlier periods.

You don't trust any of the climate scientists looked at by the IPCC because of one scientist the IPCC looked at.

The mistakes with the hockey stick were only made by one scientist. However, Mann was defended by many of the scientists involved in the IPCC and the IPCC continues to use his results even though they have been discredited. In other words: the fact that the IPCC choose to support bad science when it should have known better is why it cannot be trusted. That is why the hockey is *not* a story of a single sceintist that screwed up. It is a story of an influential group of scientists that decided that advancing their political objectives was more important than good science.

You You had different reasons for supporting those policies but they're the same policies despite that.

It really depends on which policy you are talking about. I am absolutely opposed to any policy that would be hard to reverse if AGW turns out to be grossly exaggerated. This includes carbon taxes that are combined new anti-proverty social programs via the income tax system. It also includes any sort of binding international agreements. Edited September 15, 2008 by Riverwind

[marksman]

I would have let you have the last word, however, you always completely misrepresent my arguments by taking them out of context or by simply ignoring the more detailed explanations.

As much as I'd like to let it go the fact is I don't misrepresent you or ignore your so-called detailed explanations. You like to move the goalposts when your positions are criticized or you ignore the basic facts.

For example

1) We cannot know whether the match from 1960 was the result of correct theory or model tuning.

All complex science of this type is done in this way so you're arguing against the scientific method. It proves nothing since the argument applies to all science whether it supports human caused climate change or not. When people use this method to reach a conclusion you agree with you use it as evidence for 1 course of action - do nothing - but when you don't like the conclusions then the method is flawed so we shouldn't take a different course of action - do something.

2) The models cannot reproduce the temperature trends from earlier periods.

They reproduce the trends within a range with reasonable certainty values.

Once again you've tried to set up a situation where you say the models are invalid if they match the data - see your 1st point - and they're invalid if they don't match the data - see your 2nd point. The same models were used before and after 1960 so you can't have it both ways.

The mistakes with the hockey stick were only made by one scientist. However, Mann was defended by many of the scientists involved in the IPCC and the IPCC continues to use his results even though they have been discredited. In other words: the fact that the IPCC choose to support bad science when it should have known better is why it cannot be trusted. That is why the hockey is *not* a story of a single sceintist that screwed up. It is a story of an influential group of scientists that decided that advancing their political objectives was more important than good science.

The results have not been discredited. They've been supported. Mann's work involved a questionable statistical method which even those criticizing the method said didn't prove the results were wrong. The fact that the IPCC chose to look at all of the studies and reach the conclusion supported by those studies shows that they can be trusted despite the misinformation that's out there. The only political objectives being carried about are by those who focus on one piece of work and then mischaracterize its flaws and then attempt to discredit an entire body of work based on their misinformation.

No detailed explanation changes the fact that your basic premise - that the results were proven invalid - is wrong.

[PoliticalCitizen]

I think moderate global warming is good or at least will do more good than bad.

That being said, I think we should still aim to be "emission-free" in as many ways as possible, not just because of CO2.

Now to prove my point about the benefit of global warming:

1 - We'll get a new usable continent - the Antarctica.

2 - We'll get rid of permafrost in HUGE areas of both Canada and Russia.

3 - Eventually tundras will get replaced by forests which will take care of a lot more CO2.

4 - The changing climate patterns could benefit some regions (while probably harming others).

5 - There will be more water in the oceans, possibly more oceanic life-forms.

Global warming is a change. It is only human to be afraid of the change. The result will most likely be the same whether we try to do something about it or we don't...

[Riverwind]

You like to move the goalposts when your positions are criticized or you ignore the basic facts.

Trying different approaches to making acase does not constitute 'moving goalposts'. You have yet to come with any compelling argument that refutes my claim that it is not possible to know whether the match from 1960 is the result of model tuning or a result correct theory without collecting future data. You have made lots of excuses like "that is the way science is done" or "tuning is not tuning when it is scientifically justified" or "model makers can't do it any other way". However, none of those excuses actually negate my point about how we cannot place our trust in unvalidated models because we CANNOT know if the results spurious results of model tuning.

Once again you've tried to set up a situation where you say the models are invalid if they match the data - see your 1st point - and they're invalid if they don't match the data - see your 2nd point. The same models were used before and after 1960 so you can't have it both ways.

The IPCC is bases its claims on the match from 1960, therefore, the match from 1960 is the period where tuning is the most important for them. The fact that the models got the temps from 1960 almost exactly right but missed rise from 1910-1940 is suggests that the model theory is, in fact, wrong and the match from 1960 IS the a spurious result of tuning.

The results have not been discredited. They've been supported.

That is a complete falsehood. All of the supporting studies were developed by close associates of Mann and used the same problematic tree ring data (the NAS report acknowledged that bristle cone tree ring data should not be used). The latest study by Mann appears repeat the same kind of sloppy statistics designed to produce the desired result from a much larger dataset. More imformation is here: http://www.climateaudit.org/?p=3642

The fact that truly independent studies like Loehe 2008 show very different results is evidence that the IPCC is only interested in science that supports its predetermined conclusions.

[marksman]

Trying different approaches to making acase does not constitute 'moving goalposts'.

Examples of moving goalposts include saying that hindcast models don't give "any indication of how the models may perform in the future" and when that was pointed out to be obviously false you "clarified" that what you really meant was that models shouldn't be used for public policy decisions. Those are 2 very different arguments.

You have yet to come with any compelling argument that refutes my claim that it is not possible to know whether the match from 1960 is the result of model tuning or a result correct theory without collecting future data.

I've repeatedly said that models will be validated with future data. You've repeatedly ignored that.

What I've got a problem with is when you make a different claim saying only that we don't know if these models are true because there are so many parameters. These claims of yours don't include anything about future data and are pointless. You can make those claims about any climate science if you wanted but somehow this criticism only falls on those models that show human caused climate change.

Even when presented with a clear example of 1 of your favourite sources explicitly manipulating parameters for a model you avoid the issue by switching to the argument that he wasn't really claiming that his model showed the IPCC models wrong while at the same time saying that the same work shows how the IPCC has ignored his valid contributions which would show the IPCC models wrong. It's a contradiction to say the least.

The IPCC is bases its claims on the match from 1960, therefore, the match from 1960 is the period where tuning is the most important for them. The fact that the models got the temps from 1960 almost exactly right but missed rise from 1910-1940 is suggests that the model theory is, in fact, wrong and the match from 1960 IS the a spurious result of tuning.

You keep leaping to conclusions with these black and white examples even though black and white aren't the only 2 options. 1 explanation is that it could suggest data collected since 1960 is better than data collected prior to 1960.

Also your 1st premise is again wrong. The IPCC results are based on studies of the entire 20th century not just from 1960.

1960 also isn't a special year since there is no substantial difference in the predictions before 1960 from the predictions after 1960. They fit loosely the same across the entire century's record. They aren't "almost exactly right" and they don't miss anything significant.

You appear to simply dismiss everyone except those who say that the IPCC either missed something or is corrupt. Never mind the fact that there is no such thing as an "IPCC model" since the IPCC just looks at studies done by scientists around the world.

The fact that truly independent studies like Loehe 2008 show very different results is evidence that the IPCC is only interested in science that supports its predetermined conclusions.

Yet another example of how in 2007 when the IPCC was preparing its latest report it should've looked into the future to prove to you that it was unbiased.

Edited September 16, 2008 by marksman