You have mentioned your theory on why the sun hasn't played any role in this warming many times, and it is still wrong. Just because the Sun goes through an 11 year cycle, that does not mean that it cannot warm on a 30 year time scale, nor does it mean that the temperature would have to be "rapidly fluctuating every 6 years". It is obvious you do not understand the sun, so I suggest you start doing some research on it before you claim that you have "refuted" anyone.
Second, the sun doesn't have to be warming for it to be raising Earth's temperature, and I have explained this countless times on Y!A. So I will repost:
"The Sun has gotten hotter. The fact that it did so prior to 1950, and then just pretty much just remained so, does not alter its ability to explain warming, even to this day. GHG gasses also have difficulty explaining the shape and timing of the 20th century temperature statistics without significant aerosol contributions.
No matter how suggestive the GHG concentration curves are to the naked eye relative to the plateau in solar activity, without positive feedbacks, anthropogenic GHGs can only account for less than a third of the recent warming. Credible attribution of the rest of the less than 1W/m^2 energy imbalance requires models that can reproduce the observed solar response, and have a much better “match” to the climate than current models.
Read the climate commitment studies of Wigley, et al, and Meehl, et al, to understand how the argument that recent solar activity has not increased is simplistic and wrong. If the level of solar forcing reached prior to 1950 continues (which is unlikely per Solanki), then there will be a solar contribution to the energy imblance resulting in sea level rise for several more centuries. Presumably most of the temperature response occurs in the first few decades, although arguably, that response was delayed by the causes of the midcentury cooling (aerosols, ocean circulations, etc..)."
On the stratosphere trends, I already gave you an answer on your question about it earlier this week, but you didn't feel the need to even respond, I assume because you couldn't. I'll repost:
"Why is the stratosphere cooling? Well, its not, and if you had a more up to date graph of stratospheric temperature trends you would know that--yours ends in 1999, but even from there you can see that lower stratospheric temperatures plateaued in roughly 1994, and they have continued to stay flat. However, the lower stratospheric temperature trends are complicated by ozone recovery, so we can look at upper stratosphere and we can see that temperatures have not dropped for at least 12 years. Above that we have no up to date temperature trend analysis.
Two papers by Laštovička et al (2004 and 2006) look at upper atmosphere trends ending in 1997. They both mention that geomagnetic and solar activity have played some role in the cooling upper atmosphere, but there hasn't been any particularly good assessment of the extent of their roles. And increased water vapor likely makes up a majority of the rest. CO2 is likely playing a role as well, but we don't know the extent. And in fact, a cooling upper atmosphere works well with a plateau in solar activity--having to do with the shorter time it takes for the upper atmosphere to reach equilibrium versus the oceans.
Yes, the overall trend is negative, but that does not mean that the stratosphere continues to cool. And in fact, the only real cooling we see in the lower stratosphere comes directly after the two major volcanic eruptions of the last 30 years (Pinatubo and El Chichon). Though, like I said, the lower stratospheric trends are complicated by ozone recovery."
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Edit:
(Q) You say:
"bob236 (or whatever the number) talks about how solar variations can account for the anomaly. Unfortunately, they don't even correlate with the anomaly. I'd love to see a graph that shows otherwise. It doesn't matter what trends they're capable of producing."
(R) Temperature anomaly? Like I said above, the sun doesn't have to be warming for it to influence global temperatures. Please read what I wrote above.
(Q) "bob, If I remember correctly (I think it was you that gave me the strat. cooling graph), that was just some junkscience.com graph. Personally, I disregard any 'science' that comes out of that conservative mouthpiece."
(R) I never linked to junkscience. In fact, I never read junkscience, never been to that site, don't really care about it.
(Q) "Never heard of Meehl, but here's Wigley, following up his study: 'Our results imply that, over the past century, climate change due to human influences must far outweigh the effects of changes in the Sun's brightness'"
(R) I never said they were skeptical of AGW. I said that you should read their studies to understand how heightened levels of solar activity (even if they plateau) can contribute to an imbalance for centuries.
(Q) "'Two papers by Laštovička et al . . . know the extent'
Lastovicka's team actually concluded that the cooling trends correlated with greenhouse gas trends best."
(R) I suggest you read them. They said that stratospheric temperature trends did correlate with GHGs (including water vapor), but also that "geomagnetic and solar activity have played some role in the cooling upper atmosphere, but there hasn't been any particularly good assessment of the extent of their roles." There has been no study that attributes, with actual observations, CO2 to the cooling (they studied trends ending in 1997) . Though, like I said, the cooling ended in the mid 90's.
There is no "best", it isn't one thing or the other, CO2 likely has played a role, but so have a number of other things, including the sun.
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Edit2:
(Q) "the most any peer-reviewed paper has attributed warming to the sun was Scarfetta & West, which attributed 25-35% of it to the sun."
(R) That is because we do not really understand how, in total, the sun influences climate. There is a reason the IPCC rates our understanding of how the sun influences climate as "low".
(Q) "The three paragraphs simply state that although solar activity has plateaued, it doesn't affect its ability to influence temperature, without really explaining how. Then you go on to say that GHGs have difficulty explaining 20th century statistics."
(R) Uhhh, I told you to read the climate commitment studies by Wigley, et al, and Meehl, et al. Though it may be difficult for you to find them, so here is a little help:
Meehl G. A., et al. Sciencexpress, 10.1126/science.1106663 (2005).
Wigley T. M. L., et al. Sciencexpress, 110.1126/science.1103934 (2005).
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Edit3:
(Q) Ken said:
"bob326 - Did you personally read the papers you reference or are you repeating someone else's commentary? Because as far as I'm able to see, neither the Laštovička or the Wigley/Meehl papers support the notion that the sun is responsible for the warming the 2nd half of the 20th century."
(R) Yes, i did read them. Did you? Did you understand them?
The Laštovička studies-- I never said that Lastovicka supported the sun theory, I merely mention them because they are a common reference of proponents, and because they aren't quite as "damning" of AGW as most proponents believe.
Wigley/Meehl-- The climate commitment studies by Wigley/Meehl apply to more than just GHGs, unfortunately for you. I reference them because they are a relatively easy way to understand how even fixed forcing agents can influence temperatures for centuries to come.
(Q) The last of the moh... said:
"So, essentially, you're saying the sun *may* account for the warming, or GHGs *may* account for the warming, or perhaps some other variable that we don't understand well *may* account for the warming."
(R) Let me fix that for you "So, essentially, you're saying the sun *may* account for *some* of the warming, and CO2 *likely" accounts for the some of the warming."
(Q) "Whatever you think, perhaps you can agree the number one aspect of AGW mitigation strategy--development of alternative fuels--should still be advanced, regardless of what might be causing the warming. Won't be long before oil eclipses 200/barrel, after all."
(R) Yes, I totally agree with this. Though adaptation will have to play a part, mitigation strategies should be our main focus.
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Edit4:
Ken said:
(Q) "Certainly, there are complexities, but neither of these papers seems to support your hypothesis that increased solar warming from early in the century had effects decades later. If you have any peer reviewed papers the support that notion, please provide a reference. Otherwise, it looks like speculation (yours or someone else's)."
(R) Yes it is speculation, meaning: there is no hard evidence of it (sort of like there is no hard evidence that increased CO2 will cause a warming for centuries to come, even if the current levels are fixed--they are all speculation). I never said there was. I mention it because it is quite a large uncertainty. Though, it isn't really that difficult to understand--it takes centuries for the oceans to reach equilibrium with heightened solar output, or as Wigley and Meehl note, any forcing agent. Most would agree, however, that the bulk of the response occurs in the first few decades after the plateau, though this response may have been delayed by whatever caused the mid-century cooling (aerosols, ocean circulations, etc..). All forcing agents have difficulty explaining the mid-century cooling without bringing in the shaky theory of aerosol cooling, including the sun.
(there is a character limit, so I deleted