Notice how the implication is that scientists are ignoring solar activity, they are not.
Nice one! I find that mechanism a little hard to buy as actually taking place, since more snow and ice on top of old snow and ice doesn’t change albedo. It’s extent which is important: earth being covered by reflective snow, and changes there happen at the fringes - the regions which are only snow-covered part of the time. As far as I’m aware, snow and ice extent is generally trending downward everywhere with the exception of a few wayward glaciers and yes, some bits of Antarctica. But okay, there are probably a few more possible subtractive mechanisms than clouds.
I absolutely accept this, and I’d put it as more than “likely”. The AMO for example was only discovered in 1994 according to wiki, and the flat ARGO ocean energy content has provoked various “explanations” such as strong localised downwellings of warm water, or massive sulphate increases from Chinese coal-burning. There are many holes in our understanding.
Here we come to a difference in philosophy. We have a late 20th century warming spike, a corresponding late 20th-century CO2 spike, a mechanism for the latter to directly cause part of the first, and very plausible, partly-confirmed mechanisms for the latter to amplify so as to cause most or all of the first. While I agree that more needs to be done to nail down exactly what’s going on, now is the time to be worrying about it and not thirty years further along in our great CO2 experiment.
GIGObuster, I’m aware of Dessler’s work, and it was Dessler’s measurements a few years ago that showed the average relative humidity of the Earth was falling rather that staying constant, see Satellite Finds Warming 'Relative' To Humidity | ScienceDaily
The issue isn’t whether or not there’s a positive water vapour greenhouse feedback - of course there will be. The question is how you estimate it or incorporate it into the models. You can’t simply calculate how much extra water vapour will end up in the atmosphere for a given rise in temperature. Humidity is high over the oceans and low over the deserts and all over the place in between. So what did the model makers do? Most or all of them assumed that the Earth’s relative humidity would remain fixed in the various regions and then calculated increased specific humidity from temperature increase, and then work out how much extra heat will be trapped. It’s a reasonable approach but it’s also a guess and the direct measurements show a more complicated picture whereby that simple assumption used in the models probably overestimates the water vapour amplification.
According to this blog post, Antarctic sea ice extent was trending upwards as of a couple years ago.
Well what exactly is the confirmation you are referring to?
As for the poles and ice and temperatures, NASA has a nice animation explaining the changes that occur from warming oceans in the arctic. The ice sheets get bigger when it warms.
Animation
That was 2004, and it said “might” the most up to date confirmations report that they got the water vapor feedback just about right considering the uncertainties
mentioned, that so far have turned to be not as huge as implied.
http://www.nasa.gov/topics/earth/features/vapor_warming.html
I see brazil and FX ignoring how tiresome is the point that concentrates on ice extent and ignoring the volume, even on the video linked it is clear that the context of the video is NASA explaining how that is not enough to counteract the melting observed.
According to NASA measurements, the sea level has been declining…for the past 2 years.
Question: if the glaciers (land) and Greenland ice cap are melting off, why is the sea NOT rising?:eek:
No link to see who is teeling us that uh? But I would not be surprised that is our old friend Willis Eschanbach.
What about the other Willis?
An alert commentator makes this note:
Dessler’s 2008 paper can be found online here, for anyone who wants to read it. http://geotest.tamu.edu/userfiles/229/Dessler_et_al_2008b.pdf Note that the work measures the water vapour response to short-term fluctuations (El Nino) rather an absolute rise over time. A similar paper he published a year later has its abstract here: http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI3052.1?journalCode=clim That abstract seems to imply that the fluctuation respsonse method gives both high scatter and a larger value than the global warming feedback.
If anyone’s interested, there’s a 2010 guest post by Dessler on Roger Pielke Snr.'s blog, here: Guest Post By Andrew Dessler On The Water Vapor Feedback | Climate Science: Roger Pielke Sr. and a response by Pielke arguing the point here: Reply to Andrew Dessler’s Guest Post On Water Vapor Feedback | Climate Science: Roger Pielke Sr.
Ice extent data is noisy and AGW is fairly weak in the southern hemisphere anyway. Total global ice extent is trending down, which reduces albedo.
Specific global humidity is rising globally. That is a fact comfirmed by numerous measurements and studies, see the two Pielke blog links above for lists of papers and authors. My only question is whether the various models get the size of the effect right compared with the measurements.
Just to clarify, the WUWT article is by Anthony Watts himself: http://wattsupwiththat.com/2011/08/24/nasa-notes-sea-level-is-falling-in-press-release-but-calls-it-a-pothole-on-road-to-higher-seas/
Eschenbach chimes in later with the Grace data map showing water losses and gains over area. He makes the perfectly valid point IMO that if the sea has lost 6mm in a year when it was expected to gain 3mm, then 9mm of water must have evaporated from the oceans and deposited onto the land. Furthermore, since the ocean area is much larger than the land area, the deposition has to be equivalent to about 2.3 cm of water over the entire land area. Using the colour key to the right of the map, this is equivalent to a lightish blue over the entire land area. I don’t see anything wrong with that, although I’m not so convinced that you can eyeball the map and state that the water mass-balance falls short. I think your “alert commentator’s” sarcastic use of “great contribution” was unwarranted.
Still looking at WUWT? IMHO as long as watts does not ever comes clean regarding his claims to fame (being wrong regarding the weather stations) I would not trust anything of what he says.
Regarding Eschenbach, even **Jshore ** on the dope and others were not impressed with him http://scienceblogs.com/deltoid/2009/12/willis_eschenbach_caught_lying.php.
On that note, I still go with what NASA is reporting about this.
What climate data isn’t noisy? The only thing I can think of is CO2 levels.
How do you know that?
Cite?
Can you quote the relevant parts of those blog posts? TIA.
The article on WUWT is a straight reproduction of a NASA JPL article, reproduced in its entirety with a link to the source right at the beginning. There’s nothing wrong with that.
Ralph124 stated that NASA had reported a drop in sea level. Then you suggested that he had gotten this information from Eschenbach on WUWT, based on someone’s comment following an article on Skeptical Science. Since the quoted comment was moderately derogatory I thought it only fair to link to the actual article rather than let a third-hand defamation stand.
At the end of the day, the NASA article is only a press release and it would be good to quantify how well the total water mass change over the land measured by GRACE matches the drop in sea level. That said, I’ve read enough of Josh Willis’ exchanges with Pielke Snr. to respect his opinion.
I dislike demonisation as a debate tactic and I put Deltoid’s accusation of dishonesty against Eschenbach in the same bin I put Bishop Hill’s accusation of dishonesty against John Cook of Skeptical Science (SAKURA188: Situs Live Casino Online Terbaik Indonesia 2025) I’m more interested in attacking arguments than people. I disagree with Eschenbach on a lot of things but if you ever meet the kind of skeptic who doubts CO2 is rising, or that the rise is due to us, or thinks the Mauna Loa data is bad, these Eschenbach guest posts on WUWT are great for setting them right. He’s a good communicator.
Meh, just looking at the fist one he does start ok then he trows the squik again at WUWT:
Being a good communicator does not mean that he is not putting squicky stuff like that again and again.
The idea is always to push the doubt in the end. And as it has to pointed again, there is no effort in the end to correct or learn from the mistakes they committed, that is if they **are **mistakes, the longer it goes I’m not willing to give them the benefit of the doubt. So far what I see is that the ones that are getting more often burned on discussions like this are the ones that are trying to be fair like you to the **unfair **side in all this, just like Dr Muller found by following the pied pipers at WUWT:
(Video shows Muller relying on Anthony Watts say so, only to get burned recently by the deniers as Muller is reporting that Watt’s main reason for being is not there)
Sea ice extent is particularly bad because it’s strongly affected by wind pushing floating ice around.
You can see the weaker southern hemisphere warming trend in the hemisphere temperature records. See for example http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-3-6.html from the IPCC.
Sea ice extent is tracked by various bodies - JAXA, MASIE, NSIDC. The NSIDC website is here: Sea Ice Index Daily and Monthly Image Viewer | National Snow and Ice Data Center
The Antarctic average sea ice extent graphed since 1970 is shown here: http://nsidc.org/data/seaice_index/images/s_plot_hires.png. As you stated, the extent shows a positive trend over time, although only very slightly. The corresponding Arctic extent is graphed here: http://nsidc.org/data/seaice_index/images/n_plot_hires.png i think it’s fair to say that even an eyeball assessment tells us the sum of the trends is negative.
I’m not really sure what to say here. At the end of Dessler’s guest post there’s a list of eight published papers with links to the texts of three of them. In the body of Pielke’s response there are links to the texts of two papers and various other Pielke blog posts that themselves have other links. But the point is, although Dessler is arguing for a strong water vapour feedback and Pielke is arguing that the magnitude is not settled yet, you have two published academics agreeing that there is a positive water vapour feedback and citing published observational studies to prove it.
So you agree that for the most part, climate data is noisy?
So what? It doesn’t necessarily follow that this is or isn’t the result of Mankind’s activities. Not unless you want to assume what you are trying to prove.
It’s very simple: You are making a specific claim, which is that “specific humidity is rising globally.” I am asking you to back up that claim. I looked at the very first paper you cited and it did not seem to make a claim on this issue.
I want to understand the basis for your claim that “specific humidity is rising globally” so that I can assess your argument about attribution.
Certainly. It also appears to have some quasi-periodic cycles, the causes of which we don’t really understand.
I think you may have lost track of the context of our conversation, which is probably my fault due to my infrequent posting. To recap: you proposed a negative feedback based on increased precipitation causing increased snow and ice, I pointed out that such a feedback is dependent upon ice extent, you pointed out that Antarctic ice extend has been trending up, I stated that overall, ice extent has been trending down, you asked for a cite, I gave it. The feedback mechanism you proposed does not fit with the observations of ice extent trend. I make no further claims of causation here.
Ah, fair enough. Maybe I lost track of the context that time! If you check back, I cited the exchanges of Pielke and Dessler for general interest to show differing opinions on the subject. Let’s try a more accessable cite then: http://www.cgd.ucar.edu/cas/adai/papers/Dai_JC06-sfcHumidity.pdf Figure 7 shows hemispheric and global specific humidity q over time, figure 8 shows the same for relative humidity.
Well you also stated that AGW is “fairly weak” in the southern hemisphere.
Anyway, the fact that ice extent may have been measured to be different from what one would expect if it’s part of a negative feedback loop does not rule it out as a negative feedback. You have admitted that climate data is noisy. Also, it’s possible that other forces are obscuring the feedback, agreed?
Thank you. Do you agree that if temperature increases were being caused in significant part because of things besides CO2, we would still observe a general increase in specific humidity while relative humidity would be flat?
It’s possible. A A lot of things are possible. Is it likely? If you put a pot of water on the stove, it’s possible that its rise in temperature is mostly due to a microwave beam coming in through the window, or tritium decay or whatever, but that’s not the way to bet. That doesn’t mean to say you shouldn’t investigate discrepancies in the energy balance or other stuff that doesn’t add up, but you shouldn’t lose site of the fact that the pot is on the stove. The net ice global seasonal ice extent is trending down and temperatures are trending up. The properties of ice make it quite reasonable that these observations are related.
Certainly. A watt is watt and a degree is a degree. The water vapour mechanism will amplify the Earth’s temperature response to changes in energy flux, whatever the source of the energy and whatever the sign of the change.