mersenneforum.org

mersenneforum.org (https://www.mersenneforum.org/index.php)
-   Science & Technology (https://www.mersenneforum.org/forumdisplay.php?f=52)
-   -   Climate Change (https://www.mersenneforum.org/showthread.php?t=8075)

ewmayer 2009-12-01 20:35

[QUOTE=mdettweiler;197500]Comparing the subsurface to the eastern hemisphere is a somewhat flawed analogy. The hemispheres both share the same global atmosphere, and as such, atmospheric events in one can and do affect the other. But with the subsurface, heat transfer is largely one-way. As long as the subsurface is significantly cooler, relatively speaking, than the surface waters above it (which is the case), heat will go down, from the surface to the subsurface. So, I'll admit I was a bit unclear when I said it had no particular effect on the surface...[u]what I meant to say is that it isn't going to have a warming effect on the surface[/u]. Regardless of the fact that heat content in the subsurface is increasing, it will still be relatively much cooler than the surface--which means that heat will still only flow down. The end effect on the surface would thus be essentially the same regardless of whether the subsurface is warming.[/QUOTE]
Sorry, that`s just wrong - at the simplest level of modeling the rate of cooling of the atmosphere and upper surface waters by colder subsurface waters is proportional to the temperature differential between warm and cold regions. If my refrigerator loses part of its coolant and the temperature inside rises by an average of 5 degrees C, it will "still be relatively much cooler" than my living room but nonetheless the ice cubes will melt and the food will quickly spoil.

In the case of the ocean/atmosphere dynamics, surface/deep-water interactions are a huge deal ... if the heat drawn out of the atmosphere by ocean waters drops (say) 5%, that will most certainly have a warming effect on the atmosphere, because less of the solar heating gets counteracted - you confuse "direct warming effect" (i.e. the water actually *causing* the heating) with "indirect warming effect". And there's much more to it even than the mere temperature differentials, it's the detailed *dynamics* - it's well-known that dynamical "tipping point" behavior exists for e.g. the North Atlantic Deepwater thermohaline circulation (NADW, a.k.a. Gulf Stream) ... dump too much low-density freshwater into the north Atlantic, that sits on top of the denser ocean water and shuts down the NADW flow, and northern Europe goes into ice-age conditions within a very short time, even though there's still plenty of nice warm saltwater down there in the warmer gulf regions just as before.

philmoore 2009-12-01 22:20

[QUOTE]The November 10, 2004 online version of Reason magazine reported that Lindzen is "willing to take bets that global average temperatures in 20 years will in fact be lower than they are now."[20] James Annan, a scientist involved in climate prediction, contacted Lindzen to arrange a bet. Annan and Lindzen exchanged proposals for bets, but were unable to agree. Lindzen`s final proposal was a bet that if the temperature change were less than 0.2 °C (0.36 °F), he would win. If the temperature change were between 0.2 °C and 0.4 °C the bet would be off, and if the temperature change were 0.4 °C or greater, Annan would win. He would take 2 to 1 odds.[21][/QUOTE]

Sounds like a lot of hot air to me. This guy doesn't really believe that global temperatures are going down, he just doesn't believe that they will go up as fast as many other people do. The proposed terms of the bet make this pretty clear.

ewmayer 2009-12-01 22:59

[QUOTE=philmoore;197510]Sounds like a lot of hot air to me. This guy doesn't really believe that global temperatures are going down, he just doesn't believe that they will go up as fast as many other people do. The proposed terms of the bet make this pretty clear.[/QUOTE]

That's the final version of the bet ... anyway I was more interested in the scientific arguments - got anything to say about those, or are broad-brush quips in an attempt to discredit-via-clever-wordplay more your thing? Rather reminiscent of how it's much easier for cheesehead to attempt to discredit the entire AGW-skeptical side of the argument by lengthily debating with obviously non-knowledgeable amateurs like mdettweiler rather than taking on a real scientist's objections. Cheesehead even goes so far as to make these kinds of assertions (this was addressed to mdettweiler, but makes a rather broad claim):
[QUOTE=cheesehead;197048]So far, not a single thing you've brought up has shown that the _scientific_ debate about AGW is ongoing. As _I've previously pointed out_ all you've done is give us examples that confirm my assertion that [u]the only debate involves people who have incomplete scientific understanding and knowledge[/u]. You've not yet shown even one single bit of scientific evidence (not guesses, not questions, not speculation, not mistaken assertions, but real _evidence_) against either GW or AGW.[/QUOTE]

Now perhaps cheesehead is simply admitting - in an incredibly oblique way - that *no* scientist has complete scientific understanding and knowledge (which seems very reasonable), or he genuinely believes (and this is what I think he meant) that there are no credible, knowledgeable scientists who deny "the reality of AGW". Which would be a rather remarkable claim to apply to someone of Lindzen's stature.

And speaking of credibility issues...

[url=http://www.breitbart.com/article.php?id=D9CAM0VG0&show_article=1]UK climate scientist to temporarily step down[/url]
[quote]LONDON (AP) - Britain's University of East Anglia says the director of its prestigious Climatic Research Unit is stepping down pending an investigation into allegations that he overstated the case for man-made climate change.

The university says Phil Jones will relinquish his position until the completion of an independent review into allegations that he worked to alter the way in which global temperature data was presented.

The allegations were made after more than a decade of correspondence between leading British and U.S. scientists were posted to the Web following the security breach last month.

The e-mails were seized upon by some skeptics of man-made climate change as proof that scientists are manipulating the data about its extent.[/quote]
[i]My Comment:[/i] I'll be very interested to see what their definition of "independent review" amounts to ... perhaps they can get an IPCC subcommittee to do it?

philmoore 2009-12-01 23:50

[QUOTE=ewmayer;197512]That's the final version of the bet ... anyway I was more interested in the scientific arguments - got anything to say about those, or are broad-brush quips in an attempt to discredit-via-clever-wordplay more your thing? Rather reminiscent of how it's much easier for cheesehead to attempt to discredit the entire AGW-skeptical side of the argument by lengthily debating with obviously non-knowledgeable amateurs like mdettweiler rather than taking on a real scientist's objections.[/QUOTE]

Well, Lindzen's predictions have been all over the map, from a previous prediction of a 1C rise over the next century to a later prediction of an actual decrease. My point is, the man doesn't have the courage of his "conviction" that global temperatures will fall in the next 20 years to even wage a bet without trying to at least secure very favorable odds for himself. (At one point, he was asking to be given 50 to 1 odds!) As for the "science", his claim is that water vapor is part of a negative feedback loop through cloud albedo that will offset any increase in warming caused by CO[SUB]2[/SUB]. This has been discussed and studied in the literature for at least 20 years, but this is just one feedback cycle out of the many that are involved in our climate. Here is one look at Lindzen's paper, asking why he relied on older, raw satellite data instead of the same data processed to remove instrumental effects:
[url]http://chriscolose.wordpress.com/2009/03/31/lindzen-on-climate-feedback/[/url]
Lindzen obviously has some very good ideas on trying to measure the feedback effect of cloud albedo, its just that the data does not yet seem to support his hypothesis.

mdettweiler 2009-12-02 00:00

[quote=ewmayer;197506]Sorry, that`s just wrong - at the simplest level of modeling the rate of cooling of the atmosphere and upper surface waters by colder subsurface waters is proportional to the temperature differential between warm and cold regions. If my refrigerator loses part of its coolant and the temperature inside rises by an average of 5 degrees C, it will "still be relatively much cooler" than my living room but nonetheless the ice cubes will melt and the food will quickly spoil.

In the case of the ocean/atmosphere dynamics, surface/deep-water interactions are a huge deal ... if the heat drawn out of the atmosphere by ocean waters drops (say) 5%, that will most certainly have a warming effect on the atmosphere, because less of the solar heating gets counteracted - you confuse "direct warming effect" (i.e. the water actually *causing* the heating) with "indirect warming effect". And there's much more to it even than the mere temperature differentials, it's the detailed *dynamics* - it's well-known that dynamical "tipping point" behavior exists for e.g. the North Atlantic Deepwater thermohaline circulation (NADW, a.k.a. Gulf Stream) ... dump too much low-density freshwater into the north Atlantic, that sits on top of the denser ocean water and shuts down the NADW flow, and northern Europe goes into ice-age conditions within a very short time, even though there's still plenty of nice warm saltwater down there in the warmer gulf regions just as before.[/quote]
Right, of course. Ergh, now that I look back at my post I see that my sentence about subsurface warming having no warming effect on the surface, I see that I ended up restating the same unclear statement that I was intending to correct. Oops. :rolleyes:

Okay, I'll try it again: The warming of subsurface waters would not have [i]much[/i] of a warming effect on the surface temperature. From what I could tell (not being a climatologist and thus not knowing just how much effect the raw heat increase shown in [url=http://www.skepticalscience.com/global-warming-stopped-in-1998.htm]the skepticalscience.com article cheesehead linked to[/url] would have on the actual subsurface temperature), it would seem likely that the change in subsurface temperature would not be enough to have a sizeable effect on the surface/subsurface temperature differential.

cheesehead 2009-12-02 04:33

[quote=mdettweiler;197492]Hmm...well, if the subsurface is cooling the surface because of heat flowing from the surface into the subsurface, then it would make perfect sense that the subsurface would be warming. After all, heat from the surface is being continually pulled down to the subsurface, and not going back the other way.[/quote]There are heat transfers going both ways. The ocean is full of currents that stir up water at various levels.

Are you aware that salinity differences in various parts of the ocean [I]also[/I] cause downwellings and upwellings? That the higher the salinity, the denser the water, independent of temperature? So it's possible to have warm high-salinity water that's denser than cooler lower-salinity water? And that means that sometimes warm water will sink into cool water, but other times cool water will sink into warm water?

Are you aware that water at about 39 degrees Fahrenheit is denser than water that's either colder or warmer (with equal salinity)? So you could have bottom water at 39 degrees that subsequently rises when it cools, or warms, thus stirring up the subsurface ocean?

[quote]Therefore, the subsurface is going to keep warming up regardless of whether global warming is occurring.[/quote]Your simplistic theory is not realistic.

Have you heard of El Nino and La Nina? There are different cycles of temperature going on in various areas of the oceans.

[quote=mdettweiler;197500]Comparing the subsurface to the eastern hemisphere is a somewhat flawed analogy. The hemispheres both share the same global atmosphere, and as such, atmospheric events in one can and do affect the other. But with the subsurface, heat transfer is largely one-way. As long as the subsurface is significantly cooler, relatively speaking, than the surface waters above it (which is the case), heat will go down, from the surface to the subsurface.[/quote]But that completely ignores the effect of temperature on water density. As water above 39 degrees warms, it expands, becoming less dense, so it will tend to rise compared to nearby cooler water -- bringing heat [U]up[/U], not down.

So the analogy is not nearly as flawed as you think.

[quote]So, I'll admit I was a bit unclear when I said it had no particular effect on the surface...what I meant to say is that it isn't going to have a warming effect on the surface.[/quote]Even when there's a warm upwelling? Or have you somehow outlawed such a thing's happening?

[quote]Regardless of the fact that heat content in the subsurface is increasing, it will still be relatively much cooler than the surface--which means that heat will still only flow down.[/quote]Wrong.

[quote]The end effect on the surface would thus be essentially the same regardless of whether the subsurface is warming.[/quote]Wrong.

[quote=mdettweiler;197520]The warming of subsurface waters would not have [I]much[/I] of a warming effect on the surface temperature.[/quote]Oh? Care to show us details of that calculation?

[quote]From what I could tell (not being a climatologist and thus not knowing just how much effect the raw heat increase shown in [URL="http://www.skepticalscience.com/global-warming-stopped-in-1998.htm"]the skepticalscience.com article cheesehead linked to[/URL] would have on the actual subsurface temperature), it would seem likely that the change in subsurface temperature would not be enough to have a sizeable effect on the surface/subsurface temperature differential.[/quote]"it would seem likely" ...based on what reasoning?

cheesehead 2009-12-02 04:50

[quote=ewmayer;197496]Hey, cheesehead, do you care to take time out from picking on poor mdettweiler and showing us the profound flaws in Lindzen`s arguments?[/quote]See my comments in post #487 about your rhetoric.

__HRB__ 2009-12-02 05:14

[QUOTE=mdettweiler;197520][...][/QUOTE]
[QUOTE=cheesehead;197545][...][/QUOTE]

Can you guys make up you mind, please? All this sciency and mathy stuff is getting on everybody's nerves, because it doesn't give any answers to the more important question: which pitchfork-waving lynch-mob do we feign support for during the Next Great Purge?

EDIT: Note to Godwin's law: bite me.

cheesehead 2009-12-02 06:41

Of possible interest:

"VIRGIN EARTH CHALLENGE"

[URL]http://www.virgin.com/subsites/virginearth/[/URL]

[quote]The Virgin Earth Challenge is a prize of $25m for whoever can demonstrate to the judges' satisfaction a commercially viable design which results in the removal of anthropogenic, atmospheric greenhouse gases so as to contribute materially to the stability of Earth's climate.[/quote]That's Virgin as in Virgin Atlantic Airways, so it's more big corporation money based on the AGW hypothesis, isn't it? :-)

davieddy 2009-12-02 12:35

BBC News Channel
 
Pundit: Sea level could rise by 1.4m
Interviewer: Is that globally?

ewmayer 2009-12-02 15:31

[QUOTE=cheesehead;197567]That's Virgin as in Virgin Atlantic Airways, so it's more big corporation money based on the AGW hypothesis, isn't it? :-)[/QUOTE]
Indeed it is - but in this case it`s offering to flow the other way with respect to the general citizenry as the carbon-credit-based "offers" by the likes of J.P.Morgan and Goldman Sachs.

Question: If someone comes up with a way to cheaply and safely remove CO2 from the atmosphere - say via large-area-low-concentration ocean iron fertilization - but by then the AGW hypothesis is looking more shaky than today, could Virgin refuse payment on grounds that evidence of "atmospheric stabilization" is lacking? Just wondering...


All times are UTC. The time now is 23:04.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.