Moderated Global Warming Discussion

[Furcifer]

so how would you turn off the erupting volcanos?

Why would we want to do that? A good hundred years of heightened volcanic activity is in order.

If they were a feedback induced forcing the problem would be sustaining them, not turning them down or off.

All of this is hypothetical of course, but I would assume if there were a continuous eruption that threatened to plunge us into an iceage we would have to filter the ash and neutralize the sulfurous gases. Perhaps a large ion filter?

 

[lomiller]

Any physical system of any complexity has both negative and positive feedbacks. No one is denying there are negative feedbacks. The fact is, though, that there is no reason to expect any balance. Which ones are having more effect? Given the earth's history of rather dramatic lurches from hi to lo and back to hi (as it did 20,000 years ago, for example), I would give it a rough guess that in between the stops the positive ones rather overwhelm the negatives. That is the most common reason for large fluctuations. I know of no reason to suspect that the climate is dominated by negative feedback.

There is actually a very good reason to believe positive feedback dominates. The earths response to changes in insolation are considerably larger then would be expected if there were no feedback at all. If negative feedbacks dominated you would expect the climate response to be smaller, not larger then the open loop response.

The heat capacity of the oceans is simply to great to explain the type of climate change observed in either the historical or paleo-climate record without positive feedback.

 

[lomiller]

Or perhaps not:

http://pielkeclimatesci.files.wordpress.com/2010/08/hansen88_v_obs.jpg?w=500&h=350

Edited by Tricky: 

Replaced hotlinked image with link.

I find it interesting that you enver bothered to question he’s comparing GISS numbers to UAH numbers.

The reason he did this is because UAH is the odd man out and shows a significantly lower warming trend then any of the other 4 datasets. If you take the scenario that most closely matched actual CO2 levels and compare it to GISS or any other dataset you fund that the trend predicted back in mid 80’s matches the actual trend very nicely.


http://pubs.giss.nasa.gov/docs/2006/2006_Hansen_etal_1.pdf

 

[lomiller]

BTW the RSS numbers he’s drawing look *extremely* suspect. RSS actually reports one of the largest trends over the past 30 years. This plots UAH – RSS to show how the two diverge over time (nearly 0.2 deg since 1985), yet this well know discrepancy doesn’t show up at all in the image you linked.

http://3.bp.blogspot.com/_0HiXKAFhRJ4/R5wDzBMkqfI/AAAAAAAAAgs/a7g8Mf8wpfg/s1600-h/RSS.UAH.JPG

 

[mhaze]

I've posted this here, rather than start a new thread, which I gather is the right thing to do now the AGW debates here have changed? This seems to be a catch-all thread.

Interesting to see this paper reported at ClimateAudit:

A Statistical Analysis of Multiple Temperature Proxies: Are Reconstructions of Surface Temperatures over the last 1000 years reliable?

... in which statisticians once again side with the McIntyre / McKitrick side of the paleo climate reconstruction debate.

Whilst I remain agnostic on the topic of AGW, one thing I never understood about the debate was the way the pro-AGW camp rallied around the very poor standard of statistical analysis conducted in the paleo climate reconstructions. Bad analysis is bad analysis and when people rally around bad analysis, it is simply clear that people are unwilling to hear valid criticism.

This isn't new: many heavyweight statisticians have already sided with the views of McIntyre and McKitrick, including the likes of Ed Wegman and Ian Jolliffe.

Doubtless we will get the usual crowd here defending the IPCC position. Bad news for you guys: science is self correcting. And even though climate journals are currently publishing bad analysis with outdated and incorrect statistical methods, eventually people who really understand how to do statistics will put them right. But those who defended bad science will lose an awful lot of credibility in the process.

Give me the ability to self select (from the entire set of available proxies and instrumental data) a couple dozen proxies from and intermingle them by my choice with instrumental again of my choosing, I can create just about any desired end product.

Junk science.

 

[shadron]

so how would you turn off the erupting volcanos?

http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html

Gerlach estimates that man puts 150 times more CO2 into the atmosphere than the average amount of all the volcanoes on earth, including the suboceanic ones. Further any effect that unusually large volcanoes have in warming will be counteracted by their haze effects. After all, the idea is not to eliminate all the CO2 generation that happens on Earth; only the anomalously high amount that mankind has added.

 

[macdoc]

Maybe he got the idea from this peer reviewed paper:

http://rossmckitrick.weebly.com/uplo...mh_asl2010.pdf

ah the M&M denier twins....data trends 1979 to 1999 - how very relevant
How many years did they get rejected by mainstream climate science journals until they got into the fast track online only journal a few weeks ago??

I guess the update to 2009 allowed it in the fast track online journal with grudging acknowledgement .....why fancy that - it's getting warmer

In dataspanning 1979 to 2009 the observed trends are significant in some cases but tend to differ significantly from modeled trends

When it makes Nature let us know...

Atmospheric Science Letters (ASL) is a wholly electronic journal. Its aim is to provide a fully peer reviewed publication route for new shorter contributions in the field of atmospheric and closely related sciences. Through its ability to publish shorter contributions more rapidly than conventional journals, ASL offers a framework that promotes new understanding and creates scientific debate - providing a platform for discussing scientific issues and techniques.

We encourage the presentation of multi-disciplinary work and contributions that utilise ideas and techniques from parallel areas. We particularly welcome contributions that maximise the visualisation capabilities offered by a purely on-line journal. ASL welcomes papers in the fields of:

http://ca.wiley.com/WileyCDA/WileyTitle/productCd-ASL2.html

meanwhile in the real world

NASA reports hottest January-July on record, says that 2010 is “likely” to be warmest year on record and July is “What Global Warming Looks Like”WMO: "Unprecedented sequence of extreme weather events ... matches IPCC projections of more frequent and more intense extreme weather events due to global warming."

http://climateprogress.org/2010/08/12/nasa-hottest-year-on-record-what-global-warming-looks-like/

 

[lomiller]

The Earth isn't a blackbody, it's a greybody.

Approximating the planets as black bodies works just fine for calculating their average temperature as long as they do not have an atmosphere with greenhouse gasses in it.

Anyhow, here's a good link to end this game of semantics started a few posts back:

http://www.drroyspencer.com/2009/04/when-is-positive-feedback-really-negative-feedback/

I didn’t get past the first paragraph before it became apparent this is the typical Spencer blogging crap. Spencer’s blogging has only a passing resemblance to what he actually publishes, and he typically says things he knows he would never get passed peer review and is driven by his political and religious beliefs far more then anything appears in the actual science.

Allow me to quote that first paragraph for you:

I get an amazing number of e-mails from engineers who point out that the climate system can not be dominated by positive feedback, because that would mean the climate is unstable, in which case it would have careened out of control long ago.

I happen to be an Electrical Engineer who has done some control systems work, and the claim that if the earth (or anything else) were driven by positive feedback it would careen out of control is categorically untrue. He is either making up stories of engineers saying this or the ones who did have little to no experience with control system.

Again, positive feedback can be unstable, but that isn’t even close to being universally true. In fact open loop low gain systems (like the earths climate) with positive feedback are generally stable. In systems like this positive feedback manifests as making it more sensitive to input changes, something we know is true of the earths climate.

Next he goes on to say:

But in the climate research world, the dividing line between ‘positive’ and ‘negative’ feedback is not whether extra energy is gained or lost with warming, but whether the increase is greater (or not) than the ‘temperature-only’ increase in infrared energy loss with warming.

While the earth does radiate more IR as it warms this IS NOT feedback in and of itself. Feedback, as the name implies, means part of the output is fed back to the input. Outgoing IR on it’s own does not add to or subtract from the effective incoming energy. In contrast greenhouse gasses create “back radiation”, they intercept outgoing IR and redirect it back down so it effectively adds to the incoming solar energy.

In the absence of feedbacks, this temperature-only response is estimated to be about 3.3 Watts per sq. meter per degree C at the effective radiating temperature of the Earth, which is about 255 Kelvin (-18 deg. C).

Of course, what this also means is that if positive feedbacks exceeded that 3.3 Watts, then we really DO have an unstable climate system. So, in some sense, the climate system is always 3.3 Watts in positive feedback away from oblivion.

The simplest form criteria for stability of a positive feedback system is that the open loop gain A * the feedback factor B is less then 1. A*B < 1 (in this case A > 1 would violate conservation of energy) What he’s doing above if throwing out a red herring to disguise the fact he’s assuming a rather massive B (the feedback factor)

He’s also pulling a little bate and switch, talking about W/M^2/Deg C and then simply dropping the /Deg C part and implying any back radiation above 3.3 W would make the system unstable. In short the whole thing falls into the “that’s not right. that’s not even wrong” category.

Here is what really happens when you have positive feedback:
Lets assume A = 1 and B = 0.5 and the Sun warms up enough to increase the planets blackbody temperature 1 deg C.

The warming causes some effect (say an increase in water vapor) that causes the earth to retain more heat. In this case 0.5 Deg C (1 Deg * A * B)

That 0.5 deg cause a further increase in water vapor, which causes more warming but this time only 0.25 deg (0.5 * A * B)

That 0.25 also triggers more warming, and so on.

The final amount of warming you actually see therefore is 1 + 1/2 + 1/4 +1/8…
If you do the math you will find this series converges on 2 Deg C. I.E. an increase in solar energy that would normally cause 1 deg of warming ends up causing 2 instead.

If we had looked at negative feedback instead then the final change would have been less then 1.

 

[CapelDodger]

What we don't know is if feedback can lead to forcings. It's entirely possible the change in ocean currents could lead to increased volcanic activity or some other forcing.

Not likely I realize that, but not impossible as some people seem to be insisting.

Close enough to impossible to be disregarded.

We're not about to enter a realm of new physics or new geology here. Climate influences the atmosphere, the oceans, and the land surface to no great depth. In planetary terms it's the merest skim on the globe, and there are no great mysteries left hidden in there.

As to increased volcanic activity below the oceans, that isn't going to put much suphate or ash into the air is it?

 

[Trakar]

Or perhaps not:

http://pielkeclimatesci.files.wordpress.com/2010/08/hansen88_v_obs.jpg?w=500&h=350

Edited by Tricky: 

Replaced hotlinked image with link.

Maybe he got the idea from this peer reviewed paper:

http://rossmckitrick.weebly.com/uploads/4/8/0/8/4808045/mmh_asl2010.pdf

Then perhaps he should consider using more appropriate and significant climate resources.

 

[Geckko]

I find it interesting that you enver bothered to question he’s comparing GISS numbers to UAH numbers.

The reason he did this is because UAH is the odd man out and shows a significantly lower warming trend then any of the other 4 datasets. If you take the scenario that most closely matched actual CO2 levels and compare it to GISS or any other dataset you fund that the trend predicted back in mid 80’s matches the actual trend very nicely.


http://pubs.giss.nasa.gov/docs/2006/2006_Hansen_etal_1.pdf

That is factually incorrect.

The chart plot both of the satellite measures RSS as well as UAH. They measure global mean temperature.

 

[Geckko]

Then perhaps he should consider using more appropriate and significant climate resources.

There seems to be a common misconception that some academic papers can be ignored simply on the basis of their origin or authors.

I presume that all of are aware that is logical fallacy.

 

[refamat]

http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html

Gerlach estimates that man puts 150 times more CO2 into the atmosphere than the average amount of all the volcanoes on earth, including the suboceanic ones. Further any effect that unusually large volcanoes have in warming will be counteracted by their haze effects. After all, the idea is not to eliminate all the CO2 generation that happens on Earth; only the anomalously high amount that mankind has added.

ah, but volcanoes have a direct effect upon climate. also note that it's always termed "greenhouse gasses" not "greenhouse gas", and, since geologically speaking, the earth has seen much higher average temperatures than we have experienced, as humans, the amount of CO2 we release or is released naturally may not matter at all. What people always forget is that as long as there are glaciers and ice sheets on the surface of the earth, we are technically still in an ice age. And as long as the governments can put up smokescreens they can divert attention away from more serious problems because that might affect someone's pocketbook.
I see no reason to cry about something that would have happened anyway when what is really a problem are the smoke screens put up by people to cover up for what is killing everything. but, you'll most likely say that cigarette smoke is the main killer of all of man's vices and that your drinking water is safe because the government says it is.

 

[Trakar]

There seems to be a common misconception that some academic papers can be ignored simply on the basis of their origin or authors.

I presume that all of are aware that is logical fallacy.

Agreed, just as the fact that no papers are deserving of especial note or attention simply on the basis of their origin or author. There also seems to be a widespread misperception that publication in a journal is the equivilant of acceptance by mainstream science and all publications and their content automatically stand equivilantly tall in academic merit and field relevent understanding.

 

[lomiller]

That is factually incorrect.

The chart plot both of the satellite measures RSS as well as UAH. They measure global mean temperature.

Then why do UAH and RSS appear nearly identical in the graph you presented, something we know for a fact isn’t true? (Last I checked UAH was claiming 0.12 deg per decade, ever other dataset was claiming 0.17-0.19 deg per decade, with the 0.19 number coming from RSS)

In any case the link I provided showing the 1988 model run have proved to be very accurate was an actual peer reviewed paper from PNAS. You “evidence” came from a graph taken from a blog posting. So please, next time you accuse people of lying pleased make at least a cursory effort to insure you have your facts are not random internet woo.

 

[lomiller]

There seems to be a common misconception that some academic papers can be ignored simply on the basis of their origin or authors.

I presume that all of are aware that is logical fallacy.

Only one of your links was from a published paper, and that was from a fairly obscure journal.

Furthermore, if you had read and understood it, you would have realized didn't give any particular support to your claim. It was discussing temperatures in the troposphere in the tropics, which are well know to be both difficult to measure and model with large error bands arround both.

In fact it seems to be weighing in on the Douglas et al 2007 paper claiming the models are wrong, vs Santer et al 2008 paper where a couple dozen climate scientists essentially told Douglas he didn’t know wtf he was talking about. In the conclusion he actually sides with Santer even though you are trying to use it as evidence of model inaccuracy.

In our example on temperatures in the tropical troposphere, on data ending in 1999 we find the trend differences between models and observations are only marginally significant, partially confirming the view of Santer et al. (2008) against Douglass et al. (2007).

For a real analysis of tropical troposphere temperatures, Santer et al 2008 is really one of the places where you should be looking

https://publicaffairs.llnl.gov/news/news_releases/2008/NR-08-10-05-article.pdf

In any case, this paper doesn't bring anything new to the table and has little to do with the global predictions for surface temperature made in the 80’s or since the 80's.

 

[macdoc]

Gekko

There seems to be a common misconception that some academic papers can be ignored simply on the basis of their origin or authors.

I presume that all of are aware that is logical fallacy.

It's hardly a logical fallacy....it's a necessary reality given the amount of funding provided by the fossil fuel companies to cast doubt on the reality of AGW.
http://www.care2.com/causes/global-warming/blog/exxon-is-still-funding-climate-change-deniers/
and it still goes on despite Exxon board room revolt.

I'm sure there were many "papers" supporting the Big tobacco position of "not addictive", "doesn't cause cancer".

those are/were rightly ignored as well - and in a number of cases it was the same players and institutions involved in that campaign and the anti-AGW campaign.

Just like the IDers - equal time and footing is sought to create a controversy where none exists. So too with papers like this.

 

[mhaze]

Approximating the planets as black bodies works just fine for calculating their average temperature as long as they do not have an atmosphere with greenhouse gasses in it. .....
I happen to be an Electrical Engineer who has done some control systems work......

Your analysis is not related to the reality of the planet and so it has no merit. The reality is differing compositions of the atmosphere w.r.t ice and water vapor on the poles vs the remainder of the planet. This means directly that differing feedback systems exist simultaneously, in the simplest analysis there would be 3. North pole, south pole and the rest.

These simultaneous feed backs do not have an additive sum because among other reasons, they interact with each other.

What you have shown is a fallacy in thinking that the thermodynamic balance of the planet can be simplified beyond a reasonable extent.

Oh, and by the way, Spencer's work is usually pretty rigidly constrained regarding the areas of the planet to which his analysis applies.

If you think I have it wrong and you have it right, feel free to invite Spencer to offer his opinion.

 

[lomiller]

Your analysis is not related to the reality of the planet and so it has no merit.

What I presented were basic facts and definitions regarding feedback. These do not change as complexity increases.

These simultaneous feed backs do not have an additive sum because among other reasons, they interact with each other.

Actually, unless you hit a tipping point you can assume linearity which means you can apply superposition. One reason why climate tipping points tend to scare people is that you can’t easily predict what the final outcome will be.

Oh, and by the way, Spencer's work is usually pretty rigidly constrained regarding the

I didn’t see any such constraints in the blog post being referenced. Regardless, the posing is quite simply wrong on a number of basic facts regarding feedback. This type of basic error doesn’t go away no matter how much you cherry pick.

 

[lomiller]

ah, but volcanoes have a direct effect upon climate.

Volcanoes cool the planet due to the aerosols they spew into the atmosphere. The greenhouse gassed they emit is negligible.

and, since geologically speaking, the earth has seen much higher average temperatures than we have experienced,

What you are really saying that because temperature of the earth was warmer before long before humans existed, we don’t need to worry about it getting that warm again. This view is problematic for those of us who wish to see humans continue to exist…

as humans, the amount of CO2 we release or is released naturally may not matter at all.

At one time people were not sure the Earth orbited the Sun, and saying it “may not” could have been a valid argument. Now, of course we know better, just as we know humans are causing the amount of CO2 in the atmosphere to rise and that is causing the planet to warm.