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Post by woodstove on Jul 29, 2009 14:34:57 GMT
Woodstove, you post over at Theoildrum? You've got good taste too then!! I don't. It's well possible, though, that the excerpt I highlighted had been pointed out on climate depot, wuwt, or icecap.us -- as I'm a frequent visitor to all three.
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Post by woodstove on Jul 29, 2009 15:50:16 GMT
Less so over the oceans (although still noticeable and interesting):
www.woodfortrees.org/plot/hadsst2nh/mean:12/plot/hadsst2sh/mean:12
which is among the reasons that people allege GISS and HADCRUT fail to account for heat islands properly (NH has more land)But that's exactly the pattern with the satellite temperatures. UAH shows greatest warming over NH land. It also shows the more warming over NH ocean than SH ocean. Check the trends here vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt i.e. NH land +0.22 deg per decade NH ocean +0.16 deg per decade SH Ocean +0.06 deg per decade SH Land +0.05 deg per decade What reasons do people give for this? The reasons for concern regarding urban heat island effect are well-documented on many threads on this site. As for why UAH shows the highest trend over NH land, I do not purport to know. Here is a question for you: By what mechanism does co2 disproportionately warm the Northern Hemisphere versus the Southern Hemisphere?
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Post by glc on Jul 30, 2009 9:25:08 GMT
By what mechanism does co2 disproportionately warm the Northern Hemisphere versus the Southern Hemisphere?
The SH has a much larger heat sink.
Here is a question for you. Due to it's elliptical orbit, the earth receives ~7% more solar energy in January than it does in July. So how is that raw measured temperatures are higher in July than January.
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Post by stevenotsteve on Jul 30, 2009 12:33:11 GMT
glc. Here is a question for you. Due to it's elliptical orbit, the earth receives ~7% more solar energy in January than it does in July. So how is that raw measured temperatures are higher in July than January.
Are you suggesting that CO2 causes the seasons now?? I think you will find that the tilt of the earths axis causes the seasons with the polar axis tilted away from the sun in winter & towards in summer (northern hemisphere) this overrides the elliptical orbit difference in tsi. (I think thats right anyway)
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Post by woodstove on Jul 30, 2009 13:52:19 GMT
By what mechanism does co2 disproportionately warm the Northern Hemisphere versus the Southern Hemisphere?The SH has a much larger heat sink. Here is a question for you. Due to it's elliptical orbit, the earth receives ~7% more solar energy in January than it does in July. So how is that raw measured temperatures are higher in July than January. In terms of the SH heat sink, if I read you correctly, the SH heat is "in the pipeline." (And I'm familiar with the relative temperatures at perihelion and aphelion.)
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Post by glc on Jul 30, 2009 15:24:47 GMT
Are you suggesting that CO2 causes the seasons now?? I think you will find that the tilt of the earths axis causes the seasons with the polar axis tilted away from the sun in winter & towards in summer (northern hemisphere) this overrides the elliptical orbit difference in tsi. (I think thats right anyway)
I'm not suggesting that CO2 causes the seasons and you are not right about the polar axis tilt overriding the elliptical orbit.
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Post by lamont on Jul 30, 2009 16:59:27 GMT
I've never seen scientists change the colour of their shirts so many times since this debate started! Fisrt AGW caused more hurricanes, then it caused less. The problem with hurricanes is that they are very local weather and affected by things like african dust, steering currents, wind shear, and there has never actually been a consensus. There has been some honest-to-god global warming alarmism over hurricanes that every year was supposed to be like 2005 which got amplified by the media and which was not a consensus. The best that could be said "scientifically" right now is that there is a halfway plausible argument that increased SSTs should cause the hurricanes that do form to intesify quicker and become more intense overall. That isn't a consensus, but the Weak AGW hurricane hypothesis that confines itself to intensification is more accepted than the Strong AGW hypothesis that predicts stronger hurricane seasons overall. Antarctica has its own micro-climate and its been long stated that Antarctica will respond very slowly to global warming. Even the response of the East Antarctic ice shelves to global warming is only theorized to be due to warmer southern ocean water. And if you check Bob Tisdale's article over at WUWT there's this image: i41.tinypic.com/2vwzmdj.jpgWhat struck me there is that you can really see how the Antarctic protects itself from even really major events like the 1998 El Nino. This is actually kind of obvious. The calculated forcing from GHGs is about 2W/m^2. The peak-to-trough measured TSI is about the same amount. The sun matters, just not enough to explain the whole post-1970 temperature rise, and even if we get a new Maunder Minimum, we still need to deal with GHGs. Climatogists have never said the sun doesn't matter at all. It has only been anti-AGWers who have invented that strawman. And the argument is rediculous on the face of it. Do you all really think that a bunch of halfway intelligent people really completely missed the huge hot ball of plasma in the sky? In order to make a plausable GHG warming argument, the effect of solar variability does need to be taken into account, and it has been, all along the way. You are late to the debate. Similarly, the argument about H2O saturating the CO2 absorption lines was the major objection to GHG warming arguments prior to accurate US Air Force measurements of absorption spectra in the upper atmosphere during the 1950s, but this old argument got recycled on the Internet 40+ years later by denialists, complete with 1 atm spectra of H2O and CO2. It'd help to actually check some of these ideas against the actual historical argument of the AGW scientific debate -- scientists actually thought about solar effects and H2O saturation a long time ago and there's a body of research that you should be familiar with before you make statements like "they think the sun doesn't matter", which is really ignorant.
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Post by donmartin on Jul 30, 2009 18:02:42 GMT
As I have asked previously, and will again ask, please direct me to any materials produced by IPCC that state implicitly or expressly that the Sun has measurable influence on the climate of the Earth. From my perusal of the IPCC reports, same actually dismiss such influence.
Recently, some "scientists" who have previously concluded that AGW is an inevitable phenomenon, now report and agree that the Sun may have some influence on the Earth's climate. They are, however, late to the party, and appear to be rationalising the apparent causative deficit which has arisen in relation to atmospheric carbon dioxide content and atmospheric temperature.
This is not to argue that AGW is not a real phenomenon. It may be. However, the aspect of certainty in relation to this phenomenon is absent, and therefore predictions are somewhat unreliable.
Of greater merit, perhaps, would be the realization that we are amongst the shortest lived species on earth, say 70,000 years, and our existence as a species is incredibly fragile. Better, I think, given the lack of empirical knowledge, to prepare rationally for all eventualities with focus upon survival. This would, of course, require recognition of the obvious fact we are one species and should achieve governance accordingly.
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Post by socold on Jul 30, 2009 18:24:20 GMT
Section 2.7.1 in AR4
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Post by radiant on Jul 30, 2009 18:31:49 GMT
Are you suggesting that CO2 causes the seasons now?? I think you will find that the tilt of the earths axis causes the seasons with the polar axis tilted away from the sun in winter & towards in summer (northern hemisphere) this overrides the elliptical orbit difference in tsi. (I think thats right anyway)I'm not suggesting that CO2 causes the seasons and you are not right about the polar axis tilt overriding the elliptical orbit. I am in Finland at latitude 61 and it is 21:16. The doors and windows are open, and the blinds are closed to keep the sun out. It is 25.3 indoors and around 21.5 outside after a high of 25 today. The sun will set in about 40 minutes and rise around 5 Our part of the world in summer is tilted towards the sun so that we get more hours of sunlight whatever other conditions might be present. And in winter there is this feint white thing just hovering above the horizon as often as not between about 9 and 3 and it tends to be very dry and cold and rather spectacular i have to say even when dark:-) www.youtube.com/watch?v=jgTyVkpJY3g
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Post by donmartin on Jul 30, 2009 19:58:20 GMT
Socold: Thank you very much. I will not think too hard on how I missed that as it may have something to do with my intelligence, or certainly, lack thereof.
I found the IPCC section to be interesting and instructive. What are your thoughts in relation to the author(s) saying (to paraphrase) that solar activity during the Medieval Maximum was equivalent to the current solar maximum, that "initial efforts" show that levels of solar activity in the past 70 years are exceptionally high when compared to the previous 8,000 years, and that physical processes caused by solar magnetic fields modulate the heliosphere, and I gather, by implication (this is my thought) climate on Earth?
I would summarize from the IPCC publication that there is a great deal more to learn about the Sun and its affect on us.
I do wonder about the 8,000 year business, as my reading (and we now know what that's worth) indicates the Bronze Age was a very warm period and stood at the inception of civilization as we know it today.
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