In another thread, Stephen Wilde said:
"I accept that no non condensing GHGs would result in a cooler troposphere but the system energy content need not change because the water cycle would just slow down to retain system equilibrium energy content"
I don't see how this statement can make sense. So the troposphere cools down, and so to keep system energy content constant (which is what I understand by 'retain(ing) system equilibrium energy content') then the oceans must warm up.
So how can the water cycle slow down if the oceans are warmer and the troposphere cooler, a situation that simply must result in a faster water cycle due to increased atmospheric instability?
I feel like what you're describing here is climate change as a method of planetary homeostasis - which it actually is. But in doing so you're claiming the symptom cures the disease.
You're right that climate responses limit Earth's temperature to within a certain range, however not all of that range is beneficial for human life and infrastructure as we've developed it over the last couple of hundred years.
As for a tipping point, you may have misunderstood what 'tipping point' means in the context of AGW - one example would be the release of methane from thawing permafrost. It's a tipping point in that it releases a powerful positive feedback, but it does not result in 'runaway' global warming where the planet gets hotter forever. It just means the equilibrium temperature gets warmer than it would otherwise be.
I don't see the air circulation response as a symptom but as the 'cure'.In light of the thermal efficiency of the air circulation response the system variability as regards total energy content is limited to a very narrow range.The necessary response to deal with human emissions would be infinitesimal as compared to natural variability.
"It just means the equilibrium temperature gets warmer than it would otherwise be."
I don't think that happens because global temperatures have been so stable for such long periods of time in paleological terms.
Instead a burst of methane release would just result in a slightly faster or larger water cycle with a shift in the surface air pressure distribution. That would be small in terms of natural variability such as that from MWP to LIA to date.
The system response is the same as regards ANY forcing and the effect of the response is to maintain total system energy content.
All we have to ascertain is the scale of the system response to human emissions as compared to natural changes and on all the available evidence it is miniscule.
Edited by user 25 November 2011 10:43:49(UTC) | Reason: Not specified
I think that this will be the most important of the AGW issues;
ABSTRACT FINAL ID: GC41B-0794TITLE: Ebullition-driven fluxes of methane from shallow hot spots suggest significant under-estimation of annual emission from the East Siberian Arctic ShelfSESSION TYPE: Poster
SESSION TITLE: GC41B. Permafrost and Methane: Monitoring and Modeling Fluxes of Water and Methane Associated With Arctic Changing Permafrost and Coastal Regiona I PostersAUTHORS (FIRST NAME, LAST NAME): Natalia E Shakhova1, 2, Igor Peter Semiletov1, 2, Anatoly Salyuk2, Chris Stubbs3, Denis Kosmach2, Orjan Gustafsson4
INSTITUTIONS (ALL): 1. IARC, Univerrsity Alaska Fairbanks, Fairbanks, AK, United States. 2. Laboratory of Arctic Research, Pacific Oceanological Institute FEBRAS, Vladivostok, Russian Federation. 3. University of California, Marine Science Institute, Santa Barbara, CA, United States. 4. Institute of Applied Environmental Research, Stockholm University, Stockholm, Sweden. Title of Team: ABSTRACT BODY: The high-latitude, shallow ESAS has been alternately subaerial and inundated with seawater during glacial and interglacial periods respectively. Subaerial conditions foster the formation of permafrost and associated hydrate deposits whereas inundation with relatively warm seawater destabilizes the permafrost and hydrates. Our measurements of CH4 in 1994-2000 and 2003-2010 over ESAS demonstrate the system to be in a destabilization period. First estimates of ESAS methane emissions indicated the current atmospheric budget, which arises from gradual diffusion and ebullition, was on par with estimates of methane emissions from the entire World Ocean (≈8 Tg-CH4). Large transient emissions remained to be assessed; yet initial data suggested that component could increase significantly annual emissions. New data obtained in 2008-2010 show that contribution of ebullition-driven CH4 fluxes from shallow hot spots alone could multiply previously reported annual emission from the entire ESAS.
Anyone showing that other 'warm periods' drove such releases will help convince me that todays extremes are just 'normal' workings of climate.
Any takers?
Article here, source is paywalledhttp://www.forbes.com/sites/larrybell/2012/01/10/global-warming-no-natural-predictable-climate-change/
I am dismissive of that diagram based simply on the timescales used. If he wishes to compare his model with global temperartures he needs to go back at least as far as the begining of the stellite record (1979) or the instrumental record of surface data. The fact he only goes back to 1996 to compare his model with observations suggest to me that it doesn't work very well.
I am dismissive of that diagram based simply on the fact that it is a copy of Theodor Landscheidt's work. Astrological prediction doesn't carry much weight in science!
More details here. Perhaps somone can explain his methodology.
Perhaps the guys at WUWT should ask him to publish his source code...
On WUWT they even show the full graph:
Notice anything(s) odd in comparison with the one Four so desperately wishes us to be gospel??
We can ignore the post-observational part if we like, as these are model-based and we are often told how useless models are.....
Cheers - John
I haven't looked at WUWT for weeks but it is on there in more detailhttp://wattsupwiththat.com/2012/01/09/scaffeta-on-his-latest-paper-harmonic-climate-model-versus-the-ipcc-general-circulation-climate-models/#more-54492
The Geologist responsible for this will need excommunicating toohttp://wattsupwiththat.com/2012/01/11/the-portland-state-university-study-of-shrinking-mt-adams-glaciersa-good-example-of-bad-science/
Actually, he seems to be arguing about the word 'gradual'.
I find that article confusing. The following is stated:
The answer to the question, has the climate gradually warmed over the past 100 years, is no, the climate has not gradually warmed—it has oscillated back and forth between warm and cool periods four times during the past century (Figure 1),
Yet 'Figure 1' shows clearly an upward trend. Yes, there is a clear oscillation but equally clearly each successive trough and peak is higher than the previous one.
Talk about distorting the truth.
Are you threatening me with the Comfy Chair, Four? Or are you threatening to say "Ni" to me for a Second Time?
Convert or Ostracise.
Or perhaps you could start by being honest and not devious??