SRL Archive - Discussions & Debates

Lets analyse some arguments here.


I'll quote tarajunky from the other thread.

From: tarajunky
I guess it was when I stumbled across a peer review scientific paper that apparently contradicted everything that the theory was founded on.

http://www.int-res.com/articles/cr2003/23/c023p089.pdf

According to the AGW theory, we're in a unique and unprecedented warming event that is directly caused by human activity. That paper shows that even in the last 1000 years the warming is not unprecedented, or extreme.

When finding the truth with evidence, you have to look at all the evidence. You often see this with conspiracy theories, one example is the moon-landing conspiracy theory where proponents hang onto one or two anecdotes. "There are no stars in the sky" they claim, or "the shadows all go the wrong way".

What the moon-landing theorist have done here is throw out the radar, throw out the moon rocks brought back and the telescope images where you can see the landing site. They throw out the existence of retroreflectors and just hang onto one or two dubious claims.


What has happened here is typical of a conspiracy theory, tarajunky has ignored decades of scientific papers, large amounts of evidence and just hangs onto one scientific paper, apparently without following it up to see if there is any response by other scientists.


I don't need to rebutt the claims of this paper myself because its already been rebutted by more then a dozen leading climate scientists in an article in the journal "Eos" of the American Geophysical Union.


The rebuttal raised, among other points, the following two key points:

(1) In drawing conclusions regarding past regional temperature changes from proxy records, it is essential to assess proxy data for actual sensitivity to past temperature variability. In some cases (Soon and Baliunas, 2003, Soon et al, 2003) a global ‘warm anomaly’ has been defined for any period during which various regions appear to indicate climate anomalies that can be classified as being either ‘warm’, ‘wet’, or ‘dry’ relative to ‘20th century’ conditions. Such a criterion could be used to define any period of climate as ‘warm’ or ‘cold’, and thus cannot meaningfully characterize past large-scale surface temperature changes.

(2) It is essential to distinguish (e.g. by compositing or otherwise assimilating different proxy information in a consistent manner—e.g., Jones et al., 1998; Mann et al., 1998, 1999; Briffa et al., 2001) between regional temperature changes and changes in global or hemispheric mean temperature. Specific periods of cold and warmth differ from region to region over the globe (see Jones and Mann, 2004), as changes in atmospheric circulation over time exhibit a wave-like character, ensuring that certain regions tend to warm (due, for example, to a southerly flow in the Northern Hemisphere winter mid-latitudes) when other regions cool (due to the corresponding northerly flow that must occur elsewhere). Truly representative estimates of global or hemispheric average temperature must therefore average temperature changes over a sufficiently large number of distinct regions to average out such offsetting regional changes. The specification of a warm period, therefore requires that warm anomalies in different regions should be truly synchronous and not merely required to occur within a very broad interval in time, such as AD 800-1300 (as in Soon et al, 2003; Soon and Baliunas, 2003).


source: http://www.realclimate.org/index.php/archives/2004/12/myths-vs-fact-regarding-the-hockey-stick/




I think what people have to realise is that nobody wants AGW to be true. Dealing with AGW will probably end up doing some damage to some large corporations, nobody wants that to happen but ignoring the evidence won't make it go away.
We who accept AGW aren't doing it to spite large corporations or because we hate America.

Of course you have to look at all the evidence, and then choose a side. For something that needs to have a side chosen there will always be evidence for each side. It is up to the interpriter to decide which evidence is stronger.
I'm sure that the one paper up there isn't tarajunky's sole source of information on the topic.

From: Brain
Of course you have to look at all the evidence, and then choose a side. For something that needs to have a side chosen there will always be evidence for each side. It is up to the interpriter to decide which evidence is stronger.
I'm sure that the one paper up there isn't tarajunky's sole source of information on the topic.

I agree, at some point it becomes a language game and you just pick a discourse through which you explain/justify the side that makes the most sense to you.

On this however, I do side with Yakman because I think there is a significantly larger amount of evidence pointing to the existence AGW. So significant that I personally believe it would be silly to refute AGW at this point. That is not to say it is impossible that AGW does not exist, but with the current body of evidence I think it is not probable.

I would also like to note that none of us have gone to school and studied climatology, so we are victim to the information presented to us, which could very well be manipulated to influence our thought. But in this day and age it is pretty much impossible to determine the veracity of scientific findings yourself, so I just let the experts tell me what's up. And regarding global warming, a vast majority says it exists.

I wouldn't call that rebutted at all. More like hand waving.

The paper I posted is based on the same proxy measurements that all the other AGW papers are based on. If they claim that the proxies are bad for that paper, they're really saying that the proxies are bad for all the papers.

In the whole "climate-gate" fiasco, this is exactly what they were talking about when they said they would "hide the decline". If you look at the proxies used for temperature, such a tree ring thickness, they actually go down at the end of the 20th century. But, they say, they don't need proxies for the end of the 20th century since they have satellite data and direct temperature measurements. While that is true, what does it mean for the other 1000 years they claim they can use proxies to determine temperature? If the proxies are wrong over the last 50 years, why believe that they were right every other time? So, arguing that proxies are not perfect doesn't rebut the paper, if anything it rebuts AGW.

The second criticism is that although the analysis is correct, and none of the various proxies individually point to the current temperature as extreme or unprecedented, they say that there was no "contemporaneous warming". In other words, they argue that unless all the proxies around the globe simultaneously measured a warming event, it must not really be "global warming".

But again, if you apply the exact same argument to the current climate, it fails the same criteria. The vast majority of warming is happening at the poles, while most of the globe is having a wide variety of different warming and cooling patterns. Again, it's not a rebuttal of the paper so much as a rebuttal of AGW.

That paper is very well known, and has caused a lot of controversy precisely BECAUSE it takes a sledge hammer to the foundation of the AGW theory, and they all know it.

But if proxy data is all we have to go by, and both of you are using the inaccuracy of proxies to refute each other's argument… then isn't it impossible to say whether AGW does or does not exist?

Please correct me if I misunderstood.

I also have a question. Just from a logic standpoint, doesn't it hold that if we are emitting gases that interact with the atmosphere, and there is a significantly larger (and more consumptive) population of humans on the Earth, that there would be a noticeable effect on the climate? Or is it believed that the effect we have is not significant enough to be noticed? Even if we are in a period of warming, would it not be exacerbated by human influence, to potentially devastating effect (well for us at least)?

I'm not trying to prove a point here, I'm genuinely curious!