Re: [base570] Global warming-HOAX?
Took me a while to get around to it, but I finally had a chance to watch Kirkby's entire video and I really enjoyed it. Thank you for the link.
I'm neither a physicist nor a climatologist, but it sounds like Kirkby's CLOUD experiment will be informative to climate science in one way or another, especially if they can establish a direct link between GCR and clouds. Again, I'm not a climatologist but I have the impression that clouds are one of the next big "wild cards" that need to be addressed in climate modeling and prediction. And the relationship between clouds and Glactic Cosmic Rays (GCR) seems like a worthy enough scientific topic to investigate.
So, relating this bit of science to the current thread...
Nowhere in the lecture does Kirkby deny anthropogenic causes, or the role of greenhouse gasses. The cynical folk will say that's because he doesn't want to lose his funding. Indeed, statements attributed to him many years ago(1) reflect the sentiment that GCR could explain all of global warming. In this lecture, however, he speaks of GCR as one among many significant players in the game. He also repeatedly emphasizes that the link between GCR and cloud formation is not scientifically established yet. Maybe he's become more politic, or maybe he has been swayed by the published science over the last 10 years. Of course, anyone would be thrilled to show that their research baby was the dominant climate effect. And I think we'd all love it if CO2 could be shown to be irrelevant.
Anyhow, I assume that what interested you the most was Kirkby's section about paleoclimate and sun cycles. I had two main thoughts, and I'll leave it at that for brevity's sake.
Basically, Kirkby argues that GCR cycles are correlated to all the major climate cycles as far back as we can estimate.
1) I think that's a reasonable enough hypothesis. But the context in which he presents this hypothesis, and the context in which it would be most valid, is a pre-industrial climate. If the climate has been variable (which is has), and CO2 was not forcing the cycles (which, pre-industrialization, I'll assume it wasn't), then at least one other thing (like GCR, maybe) is obviously at work. That
still does not invalidate the large body of evidence that CO2 is currently forcing a climate change.
2) One point that frequently irked me throughout Kirkby's introduction, is that he is constantly superposing curves to demonstrate correlation, without actually demonstrating any
statistical correlation. In fact, at the end of lecture, the very first question he gets asked by an audience member asks him to explain exactly that. Sadly, Kirkby does not answer the question (maybe he misunderstood it--I doubt he was trying to "dodge" anything). His case would be a lot stronger if he could show an r statistic or something like that, that "x% of the variation in curve A is explained by variation in curve B." Instead, he relies on visual superposition. Well, you can superpose the chart of any stochastic datastream, such as the dow-jones industrial average for example, with many natural (and completely unrelated!) phenomenon and claim "correlation by inspection." It's quite a weak argument until he does the math. Even if it "looks obvious." But I think the statistics would strengthen his argument, not weaken it, in this case.
So, man, this is plenty long already-- but there are no crushing attacks on AGW to be found in Kirkby's presentation. Even if there were... AGW is a
theory, and Kirkby has a
hypothesis. If he wants to upset the theory, he has to present some very rigorous data and models that 1) explain climate change better than the current models, 2) explain why CO2 is not actually responsible for effects that are both predicted and demonstrated, and 3) make new predictions that can be tested.
One thing that separates Kirkby from those on the fox-news-climate-bandwagon, is that he's actually doing science.
(1)
http://www.canada.com/...40-b687-a1672ed1f684