Sunday, August 27, 2006

Is this consistent?

You often hear the following arguments made in the AGW debate:
  1. "There is no consensus in the scientific community about AGW"

    An example can be found here in a discussion of the Oreskes Science editorial:
    "Whatever happened to the countless research papers published in the last ten years in peer-reviewed journals that show that temperatures were generally higher during the Medieval Warm Period than today, that solar variability is most likely to be the key driver of any significant climate change and that the methods used in climate modeling are highly questionable?" Peiser asked.

    "Given the countless papers published in the peer-reviewed literature over the last ten years that implicitly or explicitly disagree with the hypothesis of anthropogenic global warming, one can only conclude that all of these were simply excluded from the [Science Magazine] review. That's how it arrived at a 100 percent consensus!" he added.
  2. "Scientists are afraid to disagree with the apparent AGW consensus"

    This argument can be found in this recent WSJ oped by Dick Lindzen:
    So how is it that we don't have more scientists speaking up about this junk science? It's my belief that many scientists have been cowed not merely by money but by fear.
So which is it? Is there a vigorous debate in the scientific community about AGW, as Peiser suggests? Or is there no debate because skeptical scientists are "cowed", as Lindzen suggests? These arguments can't both be right.

Of course, perhaps they're both wrong. Maybe there's no debate because the science solidly supports the conclusion that humans are the primary driver of today's warming ... of course Peiser and Lindzen don't mention that possibility. Draw your own conclusions.

38 comments:

Anonymous said...

Dr, Dessler,

I couldn't tell ya', I'm working on grasping the mysteries of Atmospheric Chemistry at this point!

Check back with me in a few months, maybe I can make a guess by then! :^D :^D

Anonymous said...

I think perhaps we all live in our own scientific worlds, I don't know the climate computer modelers world, or the meteorologists, or several other disciplines within the AGW debate with data that is all equally valuable to the debate. To me, the meteorologists seem to be a group that has many skeptics, I also know for a fact that paleoclimatologists have many debates about AGW and I don't see a true "consensus" that man is the primary cause of climate change.

I also remember back in 1996 or so when AGU sent out a survey to me and other members about that, and as I remember, most AGU members didn't support AGW. Seems odd to me that the AGU or other like organizations involved in the debate has not done a survey in the last decade, that would be the most direct way to measure it and we wouldn't need Ms. Oreskes using google search proxies. BTW, I also did a search on Google Scholar using her parameters, but in looking at many of those abstracts, it seems the bulk of the study was not proving AGW, but rather mentioning it as a fact or proven hypothesis to build on for the referenced study.

Andrew Dessler said...

Dr. J-

Oreskes point was not that all papers *proved* AGW. She also found what you did --- that most of them simply assumed AGW's reality. Her point was that zero of the papers argued *against* AGW.

Regards

Anonymous said...

Thank you Dr. Dessler for a mature and rational response. I know she didn't break down how many of her search results were explicit vs. implicit, pity, that lacks rigor in my opinion and I wonder why she didn't spend more time researching that issue. But if all she wanted to prove is that none or very few scientists are researching that AGW doesn't exist, she is OK with it, but of course there are numerous reasons why that is the case, and most start with money, grants, media attention, and tenure based citation frenzy. Google Scholar is quite good, and much, much cheaper than ISI and more flexible.

Anonymous said...

I think Dr. J makes a good point, there is a big difference in the data, techniques, and mindsets of the various scientific disciplines involved in this study. I also know many earth scientists who reject the hypothesis that man is mostly responsible for climate change. On the other hand, it seems the young crowd involved in computer modeling are solidly, perhaps 100%, in favor of the hypothesis. But remeber, wisdom comes with age, and experience, as do so other less desireable things!

Anonymous said...

Dano,

There is a difference between saying "99% of scientists think global warming is caused by human activity" and "99% of the scientific papers published on the topic of global warming support the theory that global warming is caused by humans". What Dr. J and others have said is that they know of enough scientists in their fields to know that there is not a consensus supporting a specific conclusion. Whether or not they are correct cannot be proven by any citation you can provide unless you have a previously unpublished survey of all of the practitioners of the profession in question. Surveying the publications is useful, because it shows what has been researched and put into print, but the fact is that many scientists don't have scientifically researched data or published papers to backup their doubts, but they have doubts nonetheless. Proving a negative connection between two things is much more difficult scientifically than establishing the potential of a positive connection between the two things. In order to prove the negative, you have to prove that something else is connected. So in order to "disprove" global warming, a paper would have to not only provide data and research to discount the current theories, but also come up with enough evidence to "prove" that some other factor has a stronger effect and is therefore the more likely "cause". Most scientists that I know of who are skeptical of attributing a large role to human activity are not skeptical because they have data saying otherwise, but because they doubt that our current understanding of many of the factors other than human activity is sufficient to rule them out as significant factors as Dr. Dessler did so dismissively in his "debunking" post. In other words, they don't doubt the theory because they doubt the scientific research in support of it, but because they are unsatisfied with the level of scientific research that has been used to minimize the effect of other potential causes.

You can argue whether or not those doubts are justifiable if you like, but the fact remains that just because few people are publishing alternative theories or papers denying global warming, it doesn't mean that there is a broad consensus in all scientific fields supporting it.

Anonymous said...

Ok, so if you said the sky was purple and produced 2 dozen scientific models demonstrating that the sky was purple; and I said I believe the sky is blue, but didn't produce a paper of my own, then the scientific consensus would be that the sky is purple; even if dozens of other scientists could look up and plainly see the sky was blue and never published papers with their own thoughts on the matter? Publishing scientific ideas is great. But just because nobody has advanced an alternate theory doesn't mean that the current one has to be right or even that it is accepted by all scientists. You continue to assume that in order for somebody to have a valid doubt about your "consensus theory" they have to have a scientifically published paper espousing an alternative theory. It is possible to have a reasonable doubt based solely on not believing that the current understanding of climate is sufficient to adequately "test" ANY theory and that is precisely the doubt that many scientists in several fields have about the "consensus".

EliRabett said...

Of course, first you have to define purple and blue with respect to wavelength, but other than that Bill F is engaging in a rather slippery argument. The difference between those scientific papers that say the sky is purple and your gut opinion, is that they had to produce mechanisms and show that the mechanisms are in agreement with the
measurements.
And, of course, you would expect to see global distributions, both of measurements and predictions from theory before the idea became rooted. You, for your opinion, merely had to eat a bad hot dog.

Our Bill is playing the game that all of the claims for AGW are simply opinion, or at best unvalidated theory. He is doing the ID thing, "well, evolution is just a theory and it can be wrong." But the fact is that there is a mountain of evidence that AGW is happening and worse, the theoretical basis is an awful lot of physics, chemistry and biology. If you want to take out the AGW "theory" (scare quotes) you have to wipe out a lot of basic science, including, among other things, spectroscopy and thermodynamics.

Not the same thing at all. And yes, Virginia, the sky IS blue, Lord Rayleigh told me so.

Anonymous said...

... and, of course, unless you put something in front of your peers for them to judge it worthy of publication (or not), you haven't contributed meaningfully to the scientific conversation. it's definitely possible that a lot of scientists out there feel "in their gut" that there are surprises in store with respect to our understanding of the workings of the climate system. but anecdotal evidence, hearsay, and gut feelings are just not part of science, so when you refer to "scientists" you are by definition no longer talking about these things, in my opinion.

Anonymous said...

Chris, you will be hard pressed to find "consensus" as part of the scientific method and principles too, that is an invention of the societies and media for this topic alone, I have never heard of it in my 40 years in science before.

Anonymous said...

I am not talking about gut feelings and I am not arguing about provability of whether the sky is purple or the planet is warming. I am just saying that skepticism is a part of science. Somebody can produce all of the papers in the world saying the globe is warming, and that CO2 is rising at the same time. That is enough to produce a correlation but not a cause and effect relationship. If you then go out and perform research on CO2 forcing and come up with a theory that is backed up by models that appear to support it based on a limited data set from a very miniscule period of history, you have produced a tested hypothesis. But until you produce enough data to convince your peers that there are no OTHER viable alternative hypotheses, then they have the right to be skeptical. They don't have to produce their own alternative theories to be justified in their skepticism, they just have to believe that there is enough unexplored territory within the other possible causes to feel that your theory, while tested and published, isn't conclusive. That is where we are with AGW. There are plenty of scientists who don't disagree that the planet is warming and who don't disagree that man may have some role in it, but who feel that other processes besides global warming are understudied or completely unknown to us at this point, and therefore, they maintain their skepticism. Despite Dr. Dessler's claims or debunking, there is a huge unknown world in processes like planetary core to mantle heat flux and oceanic heat exchange that we barely have any understanding of and that we cannot possibly claim to understand well enough to say that they have no role in the current warming. Therefore, there is room for skepticism of the "consensus" even if there are no alternative theories being published. It isn't a slippery argument, it is just a difference between individual acceptance thresholds. You guys obviously accept that the current level of understanding is sufficient to accept the theory, while others simply have a higher threshhold of understanding they want to see before they accept it as well.

EliRabett said...

Yes Bill, you need thermodynamics and fluid dynamics and spectroscopy and more to produce a cause and effect relationship between greenhouse gas concentrations and a warming of the globe and you need observations to validate the theory. Which we got.

It is denialism to ignore this.

EliRabett said...

Yes Bill, you need thermodynamics and fluid dynamics and spectroscopy and more to produce a cause and effect relationship between greenhouse gas concentrations and a warming of the globe and you need observations to validate the theory. Which we got.

It is denialism to ignore this.

And, oh yes, when you convince people who are skeptical (not in deep denial), you have a consensus in science as in a consensus on spin polarization Of course Mach never accepted the existence of atoms, but there sure was a consensus that they existed.

Anonymous said...

elirabett,

" ... thermodynamics and fluid dynamics and spectroscopy ..."

Looks like I will be adding at least three more textbooks to that list you gave me a few weeks ago! :^D :^D :^D

Anonymous said...

I think nobody these days is an expert in all fields of science. So, all of us have to trust to some extent the conclusions of other scientists who have expertise that we ourselves do not have.

So, the question is how to decide who to trust and who not to trust. We should leave aside conspiracy theories of scientists just looking for money, grants etc and focus on facts as much as is possible.

each individual scientist could be a person of great integrity, intelligence and vision. Each individual scientist can also be a completely biased, corrupt and totally insane person. Luckily there are more of the former than the latter.

As we do not personally know each of these people we therefore can not judge how trustworthy the science is in a straightforward manner.

This is where consensus comes into it as I see it.. I think a theory becomes more believable as more scientists subscribe to its basic premise, as more papers are published providing evidence for the theory. It is even more convincing if those scientists come from different fields of science.

This is what I see happening in the Global warming debate. There is a overwhelming majority of scientists who subscribe to the theory of climate change being affected or caused by human actions.

These are people from different back grounds using different methods and viewpoints, yet they arrive at the same conclusions.

That for me provides a high level of confidence. You never get a complete 100% yes or no but you have to look at the weight of the evidence in the case. Right now it is on the side of climate change is happening and humans have an influence.

to date nobody has managed to come up with a testable theory that explains changes in climate as have been observed other than the increase in greenhouse gases. Skeptics of climate change need to provide an alternative testable theory that explains the observations made. Vague mentions of: the climate has always changed, scientists are just after more research funding, etc. Are not sufficient in a scientific debate.

Anonymous said...

"There is a overwhelming majority of scientists who subscribe to the theory of climate change being affected or caused by human actions."

That is the crux of this debate isn't it. You have zero evidence for that statement. You can state that "the overwhelming majority of scientific papers published on the topic of global warming subscribe to the theory that climate change is being caused by human actions", but unless you have surveyed the millions of scientists around the world, you don't know what they think. The reality is that the vast majority of the papers being published on the topic are being produced by a very small number of scientists. Statements claiming that based on those papaers, the vast majority of scientists agree with them just aren't supported by any opinion data that I am aware of.

And no, proposing an alternate testable hypothesis is not a requirement of legitimate skepticism. I am not skeptical of the hypotheses put forth as part of the "consensus view". I believe they are well founded in science and the data we have. However, I also believe that the models used to verify the hypotheses are only as good as what is put into them. If we have an inadequate understanding of one or more variables in the system, then the model will assign an inordinant amount of influence to the other processes in order to justify the changes in the data that is input. I am simply skeptical that we understand all of the processes well enough to be sure that our models are not overvaluing certain processes due to our lack of understanding of the others. I don't have to produce my own theory and publish a paper in order to be justified in that skepticism. If you want to convince me, fine convince me...but don't say that just because I haven't produced an alternative theory or published a paper, that my opinion or that of other scientists doesn't count when making broad statements about "the majority of scientists believe..."

And Eli, don't confuse the thermodynamics of atmospheric carbon dioxide with the thermodynamics of a planetary body. There is plenty we don't know about heat flux from the earth's core, heat loss into space, heat exchange between the earth and the atmosphere, heat exchange between the earth and the oceans, and geochemical processes that produce or absorb heat from the system. Face it...climate change and the debate about what is causing it is a great big thermodynamics equilibrium problem. We have a great handle on what the instantaneously recent (geologically) CO2 and temperature values are and we have some moderately good data for some small period before the last few hundred years, but in terms of understanding and quantifying all of the equations and variables that effect the thermodynamic equilibrium of the planet, we actually know very little and have relatively little data for the things we do know. So yes, we have great knowledge of how to model a thermodynamic system, but very little knowledge of whether our models are capable of incorporating processes for which we have little or no data or if the models accurately predict anything beyond the few decades for which we have signficant data density. Therefore I am skeptical...if you are not...fine. But don't pretend to think that we know all we need to about the earth's thermodynamic processes.

Anonymous said...

http://www.newscientist.com/article/mg19125676.000-ocean-plankton-absorbs-less-cosub2sub-than-expected.html

There you go Eli...all those grand models that seem to be predicting everything just right have apparently been overestimating the oceanic uptake of CO2 by billions of tons per year. So we have great thermodynamic and spectroscopic evidence to back up our models right? But what if that evidence leads us to mis-estimate an important variable and we build our models to simulate our known data set using that value? It may be that the models are not that sensitive to that particular variable, but who knows? This kind of thing is what I have been talking about in my past few posts...we just flat don't know enough to know how sure we really are of what is causing what. I think the science produced by guys like Dr. Dessler is great and cutting edge and I don't dispute in any way their knowledge or expertise...but to me our understanding of the system is incomplete given what we know today, and stories like this continue to prove that out.

Anonymous said...

With regard to there being a scientific consensus, I suggest people who disagree find out the definition of the phrase "scientific consensus".

I can not debate anybody who denies simple facts. When people crossover into denial, they leave the discussion.

I suggest people who say that because scientists were wrong here, so who knows if the other thing is true, etc., that those people visit www.theskepticsguide.org. There is an excellent list of logical fallacies and you'll find that one in it.

I also suggest you listen to their podcast as it is an excellent guide to skepticism, including global warming...

Anonymous said...

dr. j: you said, "Chris, you will be hard pressed to find "consensus" as part of the scientific method and principles too, that is an invention of the societies and media for this topic alone, I have never heard of it in my 40 years in science before."

i agree with dr. j 100% on this. consensus is not part of the scientific method at all (i'm unsure if dr. j is claiming i said it was, or what, but no matter ...).

the way it works, actually, is that application of the scientific method by members of the scientific community may produce the social construct that we call "consensus" around certain specific scientific issues, if the scientific arguments are compelling. or it may not.

this sort of consensus, being a potential by-product of the scientific method and not an element of it, is, however, an important element of scientific advisory activities. in the specific case of scientific assessments like the IPCC, the goal is to accurately portray the consensus of the peer-reviewed scientific literature as an informational tool for policy makers.

now, there are many things to examine in that approach - for example, should an assessment of the peer-reviewed literature try to reflect some kind of consensus view, or should it instead focus on the differences and breadth of opinions existing in the literature? which is more useful to policy makers, and does it depend on the particular problem under consideration? i'd like to see science policy types spend more time on that question.

bill f: i think i understand what you're trying to say, but i would still argue that saying, "i might not have any better theories, but i'm pretty sure we don't know enough about how this complex system works to accept your theory either," is a pretty weak position. you're talking about a very passive kind of scepticism that to me seems out of character with the true spirit of scientific inquiry. it is this sense of our imperfect understanding that drives the discovery process - to whit: "you don't like my theory? you think it's too neat and tidy and ignores all those things we know we don't know? fair enough - now go do something about it and get back to me when YOU'VE put something on the table for ME to criticize, like i've done. until then i'll keep saying what i believe the scientific evidence tells me."

Anonymous said...

Dano,

Its up to Dr. Dessler, but I really don't think the tone here needs to go the way of the demcraticunderground. If you disagree with me, fine...but I don't think we need to get ugly about it. Look at my response to Eli and the link I gave Mark on the more recent blog post. Both of those articles provide data about processes that are clearly not as well understood by the "consensus" as you think. Chris is right that skepticism drives scientific discovery. If Columbus had believed the consensus of the times, he never would have sailed west.

Chris, I think the process of asking questions about data and theories is just as important as actively poking holes or proposing alternative ideas. The simple act of asking a question that can't be answered by the current data often inspires the research that takes the next step forward so that the question can be answered. Questions (and the doubts that go with them) are just as important in the scientific process as any other form of debate, and my point all along has been that doubts and questions are a form of skepticism, and that skepticism is healthy for the science overall. People like Dano tend to attack skeptics and paint them as bad or harmful because they stand in the way of the mad rush to implement a bunch of expensive actions because of a theory he believes. Skeptics who are motivated by scientific curiousity absent malice or ulterior motive are just as important to the process as those whose curiosity leads them to discovery.

EliRabett said...

Not knowing everything is not equivalent to not knowing anything. Bill, you are making an argument from ignorance.

I missed it earlier, but Google Scholar is no substitute for World of Science or SciFinder (Chem Abstracts) or any of a half dozen other scientific search engines. It is much less expensive. Anyone who suggests that Google Scholar is adequit has never published. I observe this to my regret with SciFinder costing 30K$ a seat and WOS over 75K$ for a lame version.

EliRabett said...

On a serious note,"scientific consensus" among those working in a particular field is what establishes a theory.

I use the concept of a nuclear atom because today is is so basic that little kids accept it, but it was speculative as late as 1915, and even after Rutherford's experiments and Moseley's discovery of the neutron there were a bunch of bitter enders, and of course, those who really had not studied the field, but knew, just knew that the idea was crazy. There were the same tissue of issues that characterize our friendly crew of denialism.

Relativity had worse problems as it quickly became entangled in the politics of fascism and communism, both of which rejected Einstein's ideas for ideological reasons

Science is, in fact, characterized by consensus among practitioners and practitioners are narrowly defined as those who actually study and publish in the area. Once that group accepts an idea it spreads to associated fields and then to the general public.

The consensus that establishes a scientific theory is the consensus of those working in the field, if for no other reason that they are the only ones knowledgeable enough about the area to make such a judgement. The arguments here are from a bunch of characters who admit that they don't know much about the subject.

Orestes had a useful idea. She showed that among those working on climate, the idea of humans increasing global warming was for all practical purposes universally accepted.

Oh yes Bill, the phrase "the thermodynamics of atmospheric carbon dioxide" is a real WTF. If you don't understand why, you really don't have an opinion worth listening to on these issues.

Anonymous said...

Elirabett,

I've noticed that in the media coverage, "scientific concensus" is often used to suggest that there is a concensus on what practical policies to pursue, and I think that is where a lot of the confusion is coming from. People are ready to go along with reduction policies, but they have no idea what is being proposed.

The media has really failed to cover, for example, the wide array of relatively inexpensive solar power systems already available for grid tie-ins, or even the great suitability of west Texas for solar power generation stations.

I discovered, through my own efforts, that I can convert my home here in the houston area to a solar power system that comes complete with tie-in equipment for about $5,000 and I am going to that system as soon as it cools down enough for me to work outside and install it on the roof of my heavy-duty steel beam supported back porch.

But I have yet to see a single feature article or a video report on the local news about the availability of this equipment for a fraction of what it once cost!

Anonymous said...

Eli,

So which narrow group of scientists are we supposed to look to for consensus on an issue that crosses over and encompasses nearly every scientific field? And yes, the thermodynamics of greenhouse gas content in the atmosphere are a separate and distinct field from the thermodynamic relationships between the crust, the mantle, and the core. If you don't understand why, then you are proving my point by arguing.

Anonymous said...

Bill,

It is always good to ask questions. The problem is that when these questions are answered the answers are always disregarded with another "oh, but we don't know this yet..."


Anyway, I am with ttyler. We need to focus on solutions and on the fact that reducing energy usage is a good thing for people as it lowers their bills.

I for one, don't care if you reduce your energy usage because you think climate change is a real issue or because you want to lower your bills or, as far as I care, you believe fairies will come and tickle you at night if you do so.

Like the salesman said, win the order not the argument...

Anonymous said...

We finally agree on something Mark. I firmly believe that regardless of whether you believe humans are causing global warming, there are dozens of reasons to want to decrease our dependence on fossil fuels and reduce our pollutant emissions.

EliRabett said...

The people who form the scientific consensus are those that do research in the area and publish. Pretty much the way it always is. Having seen such "issues" evolve, one of the keys is that if you have one group with only old guys, it is always wrong.

Tyler is right that there is no scientific consensus on what should be done. That is about right, of course, what is really needed there is a political agreement (I use political here in a loose sense as in public policy). The best science could do in that regard is help put costs and benefits onto various proposals. As to the best sort of system to install on a house that is a moving target. Sort of like buying an air conditioning system or a computer, they keep coming out with new models.

Bill, the issue is the thermodynamics of the atmosphere. Greenhouse gases are a part of that because they can exchange energy radiatively as well as collisionally and water vapor is an important part because it can also condense. Greenhouse gases don't have a separate thermodynamics in the atmosphere as they are well mixed with the nitrogen and oxygen. For you to insist they do pretty much labels you.

Anonymous said...

From Elirabett,

" ... The best science could do in that regard is help put costs and benefits onto various proposals. As to the best sort of system to install on a house that is a moving target. ... "

Yes, Eli, that is a real problem, and I probably wouldn't be considering doing it myself if I were already getting my power on the grid from solar --- which would mean that I would not be absorbing the costs of both maintaining and updating the equipment myself, that would be a cost I would be sharing with a million other customers.

On top of that, how do you get everybody to go solar? Pass a law that we all have to put solar arrays on our homes? The simplest way is to add large-scale solar facilities to the grid, and it wouldn't surprise me to discover that's also the cheapest way to do it.

Anonymous said...

One more very quick note, i don't want to stray too far off the topic you gentlemen are actually discussing here -- but of course if a *8very large** number of people did what I am doing, it would relieve some of the demand on the public generation plants. The cost to individuals like myself of maintaining and upgrading might be offset by other benefits resulting from helping to hold down the cost of electricity to others, like say the local grocery store.

That's an area where scientists and economists could come up with some numbers for policy makers and for home owners, apartment owners, office building owners, etc, and reduce the "moving target" problem a bit.

Anonymous said...

Eli,

You are splitting hairs. If you look at the atmospheric climate, what you see is a system of various feedbacks that respond to external forcings. The significant heat flux into and out of that system only comes from two places...the sun...and the earth. There is really no process "in" the atmosphere that adds or subtracts heat from the overall system in significant quantities. The assertion made by most climate scientists claiming that humans are responsible for global warming is that the heat input from the sun is stable or at least that its rate of change is known and easily measureable, and that the rate of heat input from the earth into the atmosphere is stable or at least known and measureable. Therefore, they work with the only known major change to the atmospheric feedback system in between those two heat sources over the time period of interest, which is the change in greenhouse gas concentrations in the atmosphere. Therefore, while the thermodynamics of the whole atmosphere are what is being modeled and studied, it is the thermodynamic effects of the change in greenhouse gas concentrations that are of interest (i.e. for a given change in concentration of CO2, what is the change in the absorption of heat by the atmosphere). That is what I mean by the "thermodynamics of greenhouse gases".

The distinction that I am trying to make is that I feel that we are ignoring the potential variability of the heat flux from earth as an input into the system, which may be causing us to overestimate the thermodynamic effects of other processes or changes in processes. Most climate scientists see the earth as contributing heat to the atmosphere atmosphere through two main processes...conductive heating from isotopic decay and convection of mantle derived magma (and heat) to the surface. The long held assumption has been that the conductive heating is stable because it is a product of isotopic decay and core to mantle heat flux, and therefore has little or no variability. The core to mantle heat flux was assumed to be stable because it was assumed that changes to the core would take place over very long time frames. Therefore, it has been assumed that if we could measure the relative activity of volcanic and geothermal processes, we could properly estimate the variability in convective heating.

The assumption up until it was proven otherwise last year was that the trend of magnetic intensity from 1840 to present (which was the time period when we had detailed measurements) was consistent with the long term intensity trend. However, last year a paper was published documenting a new means of accurately calculating magentic intensity back to the 1500s.

http://www.sciencemag.org/cgi/content/full/312/5775/900?ijkey=zIUpgFJE2fXf.&keytype=ref&siteid=sci

That paper showed that beginning around 1860, the trend of the decline of the magnetic field intensity changed quite suddenly and dramatically (from about -1.6% per century to about -5% per century) and has remained that way up to the present day. The authors have hypothesized that the change in trend is related to changes in the operation of the "geodynamo" that creates the magnetic field, and such changes could result in similar changes in heat flux from the core to the mantle. If correct, that could mean that there is a heat input into the mantle that is unrelated to isotopic decay and that could cause an increase in the conductive heat flux over a relatively short timeframe without necessarily increasing volcanic or geothermal activity. If the conductive heat flux is indeed variable and not stable as previously thought, then our assumptions about volcanic and geothermal activity being accurate predictors of earth to atmosphere heat flux variability could be incorrect. Convective heat flux changes related to changes at the core to mantle boundary would take a VERY long time to show up at the surface, but the conductive heat exchange is a much faster process that could indeed begin to cause changes in the timeframe we have seen them.

So if we focus our thermodynamic attention only on the processes occurring within the atmospere and don't continue to examine what we know (and don't know) about the actual heat sources driving the system, we leave open a significant window of uncertainty in our understanding of climate change as a whole. In that regard, most "climate scientists" are chemists, meteorologists, mathmaticians, modelers, oceanogrpahers, etc., but it may be that people like geologists and geophysicists have an important role in establishing the consensus that has been understudied and underappreciated up to now.

EliRabett said...

I think you want to invest in Steorn Bill

Anonymous said...

Why? The understanding of core mantle heat flux and its relationship to geomagnetism has changed greatly in the last 5-10 years. There are numerous peer-reviewed papers published in established journals over the past few years describing areas of reversed polarity at the CMB that appear to be driving the decrease in the intensity of the magnetic field. The connection of that field's intensity to paleoclimate has also been extensively researched and published.

Do you have a published theory or data set proving those papers to be wrong? If not, according to the standards that have been expressed here by you, Dano, and others, you have no right to doubt the validity of the theories expressed in those papers.

Here is a list for you if you are really interested:

D Gubbins, A.L.Jones, & C.C. Finlay (2006); Fall in Earth’s Magnetic Field is Erratic; Science vol 312, p900-903

BTW, Gubbins won the AGU Fleming Medal in 2004 for his work...so he isn't some quack.

Acton, Gary; Short-Term Geomagnetic Variability as a Tool for Determining Precise Global Chronologies: Examples From the North Atlantic; American Geophysical Union San Francisco, California; December 5-9, 2005 (Abstract)

Quote from the above: "When the paleomagnetic records are tied to a variety of climate and environmental proxies - stable isotope,cosmogenic isotope, lithology, sediment color, rock magnetic, and other records - they become a powerful tool for examining the synchroneity of climatic events. Besides being a passive chronologic tool, however, the geomagnetic field may also play a role in climate change or be influenced by such change. Paleomagnetic records from across the North Atlantic reveal the synchroneity of the geomagnetic variability across the region, including the occurrence of multiple geomagnetic excursions during the Brunhes chron (0-780,000 years). Intriguing relationships between the geomagnetic variability and both climate change and orbital forcing suggest a causal link."

So who is Gary Acton? Associate Research Scientist and Manager of the Paleomagnetism Lab at the University of California, Davis; Honorary Research Fellow (formerly a Lecturer) in the Department of Geology & Geophysics at the University of New England, New South Wales, Australia; and Former Caswell Silver Research Professor in the Department of Earth & Planetary Sciences at the University of New Mexico. He also spent quite a bit of time working with Dr. Dessler's colleagues in the ODP at Texas A&M. Doesn't sound like a quack to me and the AGU doesn't typically invite people to speak at their events without some form of peer review of their work.

Glatzmaier, G. and P. Olson, Probing the Geodynamo, Scientific American, 292, 50-57, 2005.

Quotes from the above: "Until recently, scientists relied primarily on simple theories to explain the geodynamo and its magnetic mysteries. In the past 10 years, however, researchers have developed new ways to explore the detailed workings of the geodynamo."

and

"...the primary geomagnetic field has lessened by nearly 10 percent since it was first measured in the 1830s."

We know Scientific American isn't some fringe publication, but who are Glatzmaier and Olson?

Glatzmaeir:
Professor of Earth Sciences, UC Santa Cruz
Associate Editor, Geophysical and Astrophysical Fluid Dynamics (1990-present)
Fellow, American Geophysical Union
Fellow, Los Alamos National Laboratory
1996 IEEE Sidney Fernbach Award for Geodynamo Simulations

Olson:
Dr. Olson is a professor of geophysics and geophysical fluid dynamics at Johns Hopkins University who was elected as a Fellow of the American Academy of Arts and Sciences in 2005.

Yeah, those guys must just be a couple of quacks...I mean doesn't everybody get selected to be a fellow of the American Academy of Arts and Sciences?

The fact is that what these guys are doing is very cutting edge geophysical analysis of the mechanisms and processes of the geodynamo created by the interaction between the inner core, outer core, and mantle. Their work in the last 5-10 years has revolutionized how we understand the core-mantle interaction and how the earth's magnetic field fluctuates over time in response to changes in the core. I don't expect a climate modeler to understand it, because I am geologist and I barely understand all of it myself. But what is absolutely critical about what they are doing is that their recent work is dramatically changing our view of heat flux from the core to the mantle. Our previous understanding suggested that less than 10% of the heat flux at the earth's surface came from the mantle. Now, the work they are doing suggests that the core may contribute much more than that, and could account for up to 50% of the heat flux at the surface.

Knowing that, if I then told you that the intensity of the magnetic field created by the same processes that generate that heat had weakened by 10% since about 1840, and that that the recent weakening had occurred more than 3x faster than it had for the past 1500 years, you wouldn't then wonder what effect it might have had on the heat flux? With the close correlation of past geomagnetic intensity and climate, you wouldn't wonder at all if there was a connection?

If you don't understand the science of what I am talking about, fine...but it is peer reviewed and published scientific research that has revolutionized our understanding of a previously poorly understood part of our planet. Even if you don't understand it, you should at least accept that it is at least slightly more deserving of consideration than some modern day alchemist selling free energy. Might I suggest that you not let your arrogance about how much you think you know about climate get in you way of learning something new every once in a while?

Anonymous said...

Why? The understanding of core mantle heat flux and its relationship to geomagnetism has changed greatly in the last 5-10 years. There are numerous peer-reviewed papers published in established journals over the past few years describing areas of reversed polarity at the CMB that appear to be driving the decrease in the intensity of the magnetic field. The connection of that field's intensity to paleoclimate has also been extensively researched and published.

Do you have a published theory or data set proving those papers to be wrong? If not, according to the standards that have been expressed here by you, Dano, and others, you have no right to doubt the validity of the theories expressed in those papers.

Here is a list for you if you are really interested:

D Gubbins, A.L.Jones, & C.C. Finlay (2006); Fall in Earth’s Magnetic Field is Erratic; Science vol 312, p900-903

BTW, Gubbins won the AGU Fleming Medal in 2004 for his work...so he isn't some quack.

Acton, Gary; Short-Term Geomagnetic Variability as a Tool for Determining Precise Global Chronologies: Examples From the North Atlantic; American Geophysical Union San Francisco, California; December 5-9, 2005 (Abstract)

Quote from the above: "When the paleomagnetic records are tied to a variety of climate and environmental proxies - stable isotope,cosmogenic isotope, lithology, sediment color, rock magnetic, and other records - they become a powerful tool for examining the synchroneity of climatic events. Besides being a passive chronologic tool, however, the geomagnetic field may also play a role in climate change or be influenced by such change. Paleomagnetic records from across the North Atlantic reveal the synchroneity of the geomagnetic variability across the region, including the occurrence of multiple geomagnetic excursions during the Brunhes chron (0-780,000 years). Intriguing relationships between the geomagnetic variability and both climate change and orbital forcing suggest a causal link."

So who is Gary Acton? Associate Research Scientist and Manager of the Paleomagnetism Lab at the University of California, Davis; Honorary Research Fellow (formerly a Lecturer) in the Department of Geology & Geophysics at the University of New England, New South Wales, Australia; and Former Caswell Silver Research Professor in the Department of Earth & Planetary Sciences at the University of New Mexico. He also spent quite a bit of time working with Dr. Dessler's colleagues in the ODP at Texas A&M. Doesn't sound like a quack to me and the AGU doesn't typically invite people to speak at their events without some form of peer review of their work.

Glatzmaier, G. and P. Olson, Probing the Geodynamo, Scientific American, 292, 50-57, 2005.

Quotes from the above: "Until recently, scientists relied primarily on simple theories to explain the geodynamo and its magnetic mysteries. In the past 10 years, however, researchers have developed new ways to explore the detailed workings of the geodynamo."

and

"...the primary geomagnetic field has lessened by nearly 10 percent since it was first measured in the 1830s."

We know Scientific American isn't some fringe publication, but who are Glatzmaier and Olson?

Glatzmaeir:
Professor of Earth Sciences, UC Santa Cruz
Associate Editor, Geophysical and Astrophysical Fluid Dynamics (1990-present)
Fellow, American Geophysical Union
Fellow, Los Alamos National Laboratory
1996 IEEE Sidney Fernbach Award for Geodynamo Simulations

Olson:
Dr. Olson is a professor of geophysics and geophysical fluid dynamics at Johns Hopkins University who was elected as a Fellow of the American Academy of Arts and Sciences in 2005.

Yeah, those guys must just be a couple of quacks...I mean doesn't everybody get selected to be a fellow of the American Academy of Arts and Sciences?

The fact is that what these guys are doing is very cutting edge geophysical analysis of the mechanisms and processes of the geodynamo created by the interaction between the inner core, outer core, and mantle. Their work in the last 5-10 years has revolutionized how we understand the core-mantle interaction and how the earth's magnetic field fluctuates over time in response to changes in the core. I don't expect a climate modeler to understand it, because I am geologist and I barely understand all of it myself. But what is absolutely critical about what they are doing is that their recent work is dramatically changing our view of heat flux from the core to the mantle. Our previous understanding suggested that less than 10% of the heat flux at the earth's surface came from the mantle. Now, the work they are doing suggests that the core may contribute much more than that, and could account for up to 50% of the heat flux at the surface.

Knowing that, if I then told you that the intensity of the magnetic field created by the same processes that generate that heat had weakened by 10% since about 1840, and that that the recent weakening had occurred more than 3x faster than it had for the past 1500 years, you wouldn't then wonder what effect it might have had on the heat flux? With the close correlation of past geomagnetic intensity and climate, you wouldn't wonder at all if there was a connection?

If you don't understand the science of what I am talking about, fine...but it is peer reviewed and published scientific research that has revolutionized our understanding of a previously poorly understood part of our planet. Even if you don't understand it, you should at least accept that it is at least slightly more deserving of consideration than some modern day alchemist selling free energy. Might I suggest that you not let your arrogance about how much you think you know about climate get in you way of learning something new every once in a while?

Andrew Dessler said...

Bill-

No one is questioning whether there are changes in the Earth's magnetic field. There is indeed strong evidence that the field is weakening.

The question is whether a change in the Earth's dynamo can affect the climate. The consensus view is that the energy flux from the Earth's interior to the surface is so much less than the flux from the Sun that any trend in flux from the interior could cause any significant part of the observed trend. Combined with an explanation that is well supported quantitatively (greenhouse gases), the idea of an internal heat flow has not gained any traction.

Until some evidence arises that suggests that flux from the interior is important, this idea will continue to be ignored.

Regards

Anonymous said...

I understand your point of view on what the "consensus" believes about the issue, but tend to disagree. Several of the people who have been in the middle of the recent renaissance in geodynamo research appear to be quite interested in further study to determine if our current values for heat flux from the core are significantly underestimated, and at least a couple of them appear to be planning additional study into the close relationship between paleoclimate and geomagnetic excursions. The reason I brought this issue up on this thread in the first place is because I think it is an area of the science of climate change that is too poorly understood to dismiss it offhand as insignificant.

Andrew Dessler said...

Bill-

I'm always open to considering new theories. If and when someone publishes a theory connecting changes in core/mantle circulation with climate, I will consider that seriously. Until then, however, the reasons to ignore interior heat flux greatly outnumber reasons to consider it seriously.

Regards

Anonymous said...

Dr. J said...

"Chris, you will be hard pressed to find "consensus" as part of the scientific method and principles too, that is an invention of the societies and media for this topic alone, I have never heard of it in my 40 years in science before".

I just plugged 'consensus" into Google Scholar and got 1,470,000 hits.

Seems it is used quite frequently.

Ian Forrester

Anonymous said...

Magnetic field strenth and global temperature relation: see article http://www.gsaaj.org/articles/TempPaperv1n22007.pdf