Re: [asa] The Climate Science Isn't Settled

From: Randy Isaac <randyisaac@comcast.net>
Date: Wed Dec 02 2009 - 12:10:37 EST

You are absolutely right and it is a vital point. I think I mentioned in one
of my posts that while we are aware of quite a few positive feedback
mechanisms, we know less about the negative ones. We know they do exist and
have some general ideas about them but are not as well known. The clouds
that Lindzen mentioned may be one of the them but we don't know for sure.
The biggest problem is that most of the negative forcings we know about
won't seriously kick in until the planet warms up a good deal or until we
wait long enough for the natural orbital cycles to come around (like a
90,000 year cycle). I heard some indications last week, though I can't
substantiate them, that a warmer planet will radiate heat more efficiently
and thereby limit the amount of warming. That may well be true and makes
sense thermodynamically, but that doesn't provide cooling, just limits
warming and doesn't help us quantify it very well. Lots more research to be
done.

The C13/C12 ratio is not connected with solar irradiance. I believe it is
C14 that is affected by solar, or at least cosmic ray, factors. The argument
is simple. The fraction of carbon in today's world that is C13 instead of
C12 is 1.12%. The main process that differentiates C13 ratios is
biological--plants for example take up CO2 with a slight preference for C12
so that carbon in any biomass is lower in C13 than the atmosphere. Depending
on the type of plants, different degrees of differentiation can be detected.
By carefully studying the total mass available and various processes, they
can figure out where the carbon is coming from. Page 5 of that big file I
referred to last time,
http://www.esrl.noaa.gov/gmd/co2conference/pdfs/zachos.pdf shows a study of
all sources of carbon and the deviation of C13 concentrations in all of
them.
As for the source of the C13 dip in the Paleocene/Eocene boundary, that is a
major focus of the research. I frankly don't recall all the details of what
he said and the charts in that file are beyond my understanding. But there
are scenarios surrounding ocean dynamics and foraminifera that the authors
examine in great detail from pages 26 to 44. I believe this is a continuing
research area.

Randy

--------------------------------------------------
From: "Bill Powers" <wjp@swcp.com>
Sent: Wednesday, December 02, 2009 8:23 AM
To: "Randy Isaac" <randyisaac@comcast.net>
Cc: <asa@calvin.edu>
Subject: Re: [asa] The Climate Science Isn't Settled

> Randy:
>
> The question I keep wondering about, and the data that you present
> addresses, is that we seem to know a lot about and speak about positive
> forcing (e.g., rising CO2), but little is heard about negative forcing.
> It should be apparent that both are present, otherwise the terrestrial
> climate could not be stable over long time scales.
>
> You say that there was about a 5 deg C rise (amazing!), but that it
> "recovered" in about 100K yrs. You associate (causally?) the dramatic
> temperature rise with rising CO2, but what mechanism caused the
> "recovery." Rising temperatures ought to increase more importantly
> water vapor in the atmosphere, a more important green house gas than
> CO2. Increased cloud cover might increase terrestrial albedo, thereby
> decreasing solar irradiance on the earth's surface. But this affect
> ought to depend critically on the kind of cloud cover (e.g., not
> cirrus).
>
> One last question what is the logic behind the C13/C12 ratios? Does
> increasing C13 indicate more solar irradiance at higher atmospheric
> levels? What else?
>
> thanks,
>
> bill
>
> On Tue, 1 Dec 2009, Randy Isaac wrote:
>
>> I do indeed wish the data were inconclusive. If only Lindzen were right
>> that
>> doubling of CO2 would only lead to warming of a few tenths of a degree
>> Fahrenheit. I'm trying to figure out how we might be able to justify that
>> number and I'm totally baffled. None of the models I've seen are in that
>> range. The sad state of affairs is that all the evidence from a. past
>> history, b. present events, and c. model projections leads to
>> catastrophic
>> results sooner or later. The uncertainty is only the time frame. I wish
>> very
>> much that you could show me a skeptic who has data to the contrary. Right
>> now, sea level rise projections range from a minimum of about 2 feet to
>> tens
>> of meters. The former would be for 2100 and the latter would be later.
>> But
>> even a few feet is catastrophic, especially to underdeveloped countries.
>>
>> You are right that we don't have "certain" evidence. The IPCC carefully
>> calculates about a 90% probability, so that isn't 100%. BTW, listening to
>> the
>> intermediate data trajectories, the 2007 IPCC projections were too low
>> for
>> several parameters, most notably the rate of increase of CO2 emissions
>> and of
>> sea level rise projections. We have evidence, it just isn't 100% certain.
>>
>> As for the cost, that's an important one to weigh. Future cost if we
>> don't
>> act vs current costs if we do. I do want to draw everyone's attention to
>> a
>> presentation at the 50th anniversary conference that I mentioned
>> previously.
>> Robert Socolow from Princeton gave a lucid talk about what needs to be
>> done
>> to bring CO2 emission levels to be constant at current levels.
>> http://www.esrl.noaa.gov/gmd/co2conference/pdfs/socolow.pdf
>>
>> and one more point if I may. Last February at the AAAS meeting, I heard a
>> very interesting talk by Zachos about a particular event in history at
>> the
>> Paleocene/Eocene boundary at 55 million years ago. This time period has
>> some
>> similarities to our situation today. It seems that CO2 level rose
>> abruptly at
>> that time and they've been able to assess the thermal response. There was
>> a
>> 2.5% dip in C13/C12 ratio which recovered in about a hundred thousand
>> years
>> or possibly less. This led to a 5C rise in temperature and a major change
>> in
>> ocean acidification, which also recovered in about that time. The full
>> and
>> rather large file with all the gory details can be found at this website:
>> http://www.esrl.noaa.gov/gmd/co2conference/pdfs/zachos.pdf. The point is
>> simply that there has been at least one CO2 spike in history which led to
>> a
>> 5C rise and that took tens of thousands of years to recover. It could
>> happen
>> again.
>>
>> I long for comparable quality field work from anyone that indicates CO2
>> spikes would not have a severe impact. Please show me some.
>>
>> Randy
>>
>>
>>
>> --------------------------------------------------
>> From: "John Walley" <john_walley@yahoo.com>
>> Sent: Tuesday, December 01, 2009 8:54 PM
>> To: "Randy Isaac" <randyisaac@comcast.net>; <asa@calvin.edu>
>> Subject: Re: [asa] The Climate Science Isn't Settled
>>
>>> Randy,
>>>
>>> Thanks for this very reasoned response. It makes it easy to trust your
>>> insight. If all the AGW scientists were as gracious as this I dare say
>>> we
>>> likely wouldn't have the controversy we do. I do have one additional
>>> question though.
>>>
>>> You say:
>>>
>>> "What I think he fails to deal with adequately is the global thermal
>>> response to an unprecedented rate of rise of both CO2 and methane. He
>>> claims that there is insufficient evidence to indicate that the result
>>> would be catastrophic. But has he any data to show it wouldn't be? He
>>> seems
>>> to imply that the thermal response has been very small despite a 30%
>>> rise
>>> in CO2 and that this indicates the earth isn't that sensitive. But a
>>> hundred years or two aren't very long for a large thermal mass to
>>> respond.
>>> It seems to me to be more wishful thinking that somehow clouds will
>>> materialize to save our planet. How I hope he's right. But I wish he had
>>> some good data to support it rather than just doubting the data that
>>> indicate there's a problem brewing."
>>>
>>> I agree we would all like to see more to data to help us settle the
>>> question of whether the result of increased CO2 would be catastrophic or
>>> not. But in the absence of this data, are we certain that the results
>>> WOULD
>>> be catastrophic? Do we have any more convincing evidence to support
>>> this
>>> opposite conclusion or is it just an extrapolation?
>>>
>>> Wouldn't Lindzen and others say that in the absence of certain evidence
>>> that we not jump to conclusions? Isn't that valid when we are talking
>>> about
>>> a very large scale impact on standards of living around the world?
>>>
>>> If the recourse was something simple like just buckling up your seat
>>> belt I
>>> think we would all be on board, but when the consequences are so
>>> drastic,
>>> isn't it reasonable to make sure we are more certain with the science?
>>>
>>> Thanks
>>>
>>> John
>>>
>>>
>>>
>>>
>>> ----- Original Message ----
>>> From: Randy Isaac <randyisaac@comcast.net>
>>> To: asa@calvin.edu
>>> Sent: Tue, December 1, 2009 10:23:02 AM
>>> Subject: Re: [asa] The Climate Science Isn't Settled
>>>
>>> This article came out the night before I was debating a friend of mine
>>> on
>>> global warming as guest lecturers in a classroom last week. He surprised
>>> me
>>> with it since I had missed it. Lindzen is a well known figure in this
>>> debate. He has a reasoned tone, at least in this piece, and raises
>>> specific
>>> points that can be discussed. I think that is very helpful and healthy
>>> for
>>> the debate. Here are some initial reactions I would have to this
>>> article:
>>>
>>> "It is generally accepted that a doubling of CO2 will only produce a
>>> change
>>> of about two degrees Fahrenheit if all else is held constant." I don't
>>> have
>>> the citation handy right now but I think the value I've seen in the
>>> literature is running closer to 3 degrees Centigrade. That's a big
>>> difference. I wonder where he gets that.
>>>
>>> He's right, I think, about the uncertainty of water vapor and clouds. In
>>> general, we know more about potential positive feedback than negative
>>> feedbacks. How we hope the negative feedbacks will be stronger than we
>>> think. Unfortunately, his uncertainty argument can go both ways. The
>>> situation may be more dire or less severe.
>>>
>>> "Some have suggested CO2—but the amount needed was thousands of times
>>> greater than present levels and incompatible with geological evidence."
>>> I
>>> don't understand what he is saying. Measured values, if I understood it
>>> correctly, for global temperatures 12C higher than today were correlated
>>> with CO2 levels of about 1000ppm, not a thousand times higher than
>>> today.
>>> Perhaps he's saying the models would require more CO2 to explain the
>>> temperature? If so, then perhaps the models are underestimating the
>>> effect
>>> of CO2.
>>>
>>> " The notion that complex climate "catastrophes" are simply a matter of
>>> the
>>> response of a single number, GATA, to a single forcing, CO2 (or solar
>>> forcing for that matter), represents a gigantic step backward in the
>>> science of climate." It seems to me that no one is suggesting a single
>>> number responding to a single forcing. That's a significant
>>> oversimplification. What I've seen in the literature is an analysis of
>>> many
>>> trends responding to the full set of forcings. I don't understand his
>>> comment.
>>>
>>> What I think he fails to deal with adequately is the global thermal
>>> response to an unprecedented rate of rise of both CO2 and methane. He
>>> claims that there is insufficient evidence to indicate that the result
>>> would be catastrophic. But has he any data to show it wouldn't be? He
>>> seems
>>> to imply that the thermal response has been very small despite a 30%
>>> rise
>>> in CO2 and that this indicates the earth isn't that sensitive. But a
>>> hundred years or two aren't very long for a large thermal mass to
>>> respond.
>>> It seems to me to be more wishful thinking that somehow clouds will
>>> materialize to save our planet. How I hope he's right. But I wish he had
>>> some good data to support it rather than just doubting the data that
>>> indicate there's a problem brewing.
>>>
>>> Randy
>>> --------------------------------------------------
>>> From: "John Walley" <john_walley@yahoo.com>
>>> Sent: Tuesday, December 01, 2009 8:35 AM
>>> To: "AmericanScientificAffiliation" <asa@calvin.edu>
>>> Subject: [asa] The Climate Science Isn't Settled
>>>
>>>>
>>>>
>>>> This is from a well known skeptic who appears to be qualified in the
>>>> field. He seems to be saying that the additional CO2 is not established
>>>> as
>>>> proving temp increases.
>>>>
>>>> "Even a doubling of CO2 would only upset the original balance between
>>>> incoming and outgoing radiation by about 2%. This is essentially what
>>>> is
>>>> called "climate forcing."
>>>>
>>>> I am curious if there is any technical response to his arguments from
>>>> any
>>>> of the AGW proponents on the list. Besides the fact that he is in the
>>>> pocket of the coal companies.
>>>>
>>>> Thanks
>>>>
>>>> John
>>>>
>>>> The Climate Science Isn't Settled
>>>> Confident predictions of catastrophe are unwarranted.
>>>> http://online.wsj.com/article/SB10001424052748703939404574567423917025400.html
>>>> By RICHARD S. LINDZEN
>>>> Is there a reason to be alarmed by the prospect of global warming?
>>>> Consider that the measurement used, the globally averaged temperature
>>>> anomaly (GATA), is always changing. Sometimes it goes up, sometimes
>>>> down,
>>>> and occasionally—such as for the last dozen years or so—it does little
>>>> that can be discerned.
>>>>
>>>> Claims that climate change is accelerating are bizarre. There is
>>>> general
>>>> support for the assertion that GATA has increased about 1.5 degrees
>>>> Fahrenheit since the middle of the 19th century. The quality of the
>>>> data
>>>> is poor, though, and because the changes are small, it is easy to nudge
>>>> such data a few tenths of a degree in any direction. Several of the
>>>> emails
>>>> from the University of East Anglia's Climate Research Unit (CRU) that
>>>> have
>>>> caused such a public ruckus dealt with how to do this so as to maximize
>>>> apparent changes.
>>>>
>>>> The general support for warming is based not so much on the quality of
>>>> the
>>>> data, but rather on the fact that there was a little ice age from about
>>>> the 15th to the 19th century. Thus it is not surprising that
>>>> temperatures
>>>> should increase as we emerged from this episode. At the same time that
>>>> we
>>>> were emerging from the little ice age, the industrial era began, and
>>>> this
>>>> was accompanied by increasing emissions of greenhouse gases such as
>>>> CO2,
>>>> methane and nitrous oxide. CO2 is the most prominent of these, and it
>>>> is
>>>> again generally accepted that it has increased by about 30%.
>>>>
>>>> The defining characteristic of a greenhouse gas is that it is
>>>> relatively
>>>> transparent to visible light from the sun but can absorb portions of
>>>> thermal radiation. In general, the earth balances the incoming solar
>>>> radiation by emitting thermal radiation, and the presence of greenhouse
>>>> substances inhibits cooling by thermal radiation and leads to some
>>>> warming.
>>>>
>>>> That said, the main greenhouse substances in the earth's atmosphere are
>>>> water vapor and high clouds. Let's refer to these as major greenhouse
>>>> substances to distinguish them from the anthropogenic minor substances.
>>>> Even a doubling of CO2 would only upset the original balance between
>>>> incoming and outgoing radiation by about 2%. This is essentially what
>>>> is
>>>> called "climate forcing."
>>>>
>>>> There is general agreement on the above findings. At this point there
>>>> is
>>>> no basis for alarm regardless of whether any relation between the
>>>> observed
>>>> warming and the observed increase in minor greenhouse gases can be
>>>> established. Nevertheless, the most publicized claims of the U.N.'s
>>>> Intergovernmental Panel on Climate Change (IPCC) deal exactly with
>>>> whether
>>>> any relation can be discerned. The failure of the attempts to link the
>>>> two
>>>> over the past 20 years bespeaks the weakness of any case for concern.
>>>>
>>>> The IPCC's Scientific Assessments generally consist of about 1,000
>>>> pages
>>>> of text. The Summary for Policymakers is 20 pages. It is, of course,
>>>> impossible to accurately summarize the 1,000-page assessment in just 20
>>>> pages; at the very least, nuances and caveats have to be omitted.
>>>> However,
>>>> it has been my experience that even the summary is hardly ever looked
>>>> at.
>>>> Rather, the whole report tends to be characterized by a single iconic
>>>> claim.
>>>>
>>>> The main statement publicized after the last IPCC Scientific Assessment
>>>> two years ago was that it was likely that most of the warming since
>>>> 1957
>>>> (a point of anomalous cold) was due to man. This claim was based on the
>>>> weak argument that the current models used by the IPCC couldn't
>>>> reproduce
>>>> the warming from about 1978 to 1998 without some forcing, and that the
>>>> only forcing that they could think of was man. Even this argument
>>>> assumes
>>>> that these models adequately deal with natural internal
>>>> variability—that
>>>> is, such naturally occurring cycles as El Nino, the Pacific Decadal
>>>> Oscillation, the Atlantic Multidecadal Oscillation, etc.
>>>>
>>>> Yet articles from major modeling centers acknowledged that the failure
>>>> of
>>>> these models to anticipate the absence of warming for the past dozen
>>>> years
>>>> was due to the failure of these models to account for this natural
>>>> internal variability. Thus even the basis for the weak IPCC argument
>>>> for
>>>> anthropogenic climate change was shown to be false.
>>>>
>>>> Of course, none of the articles stressed this. Rather they emphasized
>>>> that
>>>> according to models modified to account for the natural internal
>>>> variability, warming would resume—in 2009, 2013 and 2030, respectively.
>>>>
>>>> But even if the IPCC's iconic statement were correct, it still would
>>>> not
>>>> be cause for alarm. After all we are still talking about tenths of a
>>>> degree for over 75% of the climate forcing associated with a doubling
>>>> of
>>>> CO2. The potential (and only the potential) for alarm enters with the
>>>> issue of climate sensitivity—which refers to the change that a doubling
>>>> of CO2 will produce in GATA. It is generally accepted that a doubling
>>>> of
>>>> CO2 will only produce a change of about two degrees Fahrenheit if all
>>>> else
>>>> is held constant. This is unlikely to be much to worry about.
>>>>
>>>> Yet current climate models predict much higher sensitivities. They do
>>>> so
>>>> because in these models, the main greenhouse substances (water vapor
>>>> and
>>>> clouds) act to amplify anything that CO2 does. This is referred to as
>>>> positive feedback. But as the IPCC notes, clouds continue to be a
>>>> source
>>>> of major uncertainty in current models. Since clouds and water vapor
>>>> are
>>>> intimately related, the IPCC claim that they are more confident about
>>>> water vapor is quite implausible.
>>>>
>>>> There is some evidence of a positive feedback effect for water vapor in
>>>> cloud-free regions, but a major part of any water-vapor feedback would
>>>> have to acknowledge that cloud-free areas are always changing, and this
>>>> remains an unknown. At this point, few scientists would argue that the
>>>> science is settled. In particular, the question remains as to whether
>>>> water vapor and clouds have positive or negative feedbacks.
>>>>
>>>> The notion that the earth's climate is dominated by positive feedbacks
>>>> is
>>>> intuitively implausible, and the history of the earth's climate offers
>>>> some guidance on this matter. About 2.5 billion years ago, the sun was
>>>> 20%-30% less bright than now (compare this with the 2% perturbation
>>>> that a
>>>> doubling of CO2 would produce), and yet the evidence is that the oceans
>>>> were unfrozen at the time, and that temperatures might not have been
>>>> very
>>>> different from today's. Carl Sagan in the 1970s referred to this as the
>>>> "Early Faint Sun Paradox."
>>>>
>>>> For more than 30 years there have been attempts to resolve the paradox
>>>> with greenhouse gases. Some have suggested CO2—but the amount needed
>>>> was
>>>> thousands of times greater than present levels and incompatible with
>>>> geological evidence. Methane also proved unlikely. It turns out that
>>>> increased thin cirrus cloud coverage in the tropics readily resolves
>>>> the
>>>> paradox—but only if the clouds constitute a negative feedback. In
>>>> present terms this means that they would diminish rather than enhance
>>>> the
>>>> impact of CO2.
>>>>
>>>> There are quite a few papers in the literature that also point to the
>>>> absence of positive feedbacks. The implied low sensitivity is entirely
>>>> compatible with the small warming that has been observed. So how do
>>>> models
>>>> with high sensitivity manage to simulate the currently small response
>>>> to a
>>>> forcing that is almost as large as a doubling of CO2? Jeff Kiehl notes
>>>> in
>>>> a 2007 article from the National Center for Atmospheric Research, the
>>>> models use another quantity that the IPCC lists as poorly known (namely
>>>> aerosols) to arbitrarily cancel as much greenhouse warming as needed to
>>>> match the data, with each model choosing a different degree of
>>>> cancellation according to the sensitivity of that model.
>>>>
>>>> What does all this have to do with climate catastrophe? The answer
>>>> brings
>>>> us to a scandal that is, in my opinion, considerably greater than that
>>>> implied in the hacked emails from the Climate Research Unit (though
>>>> perhaps not as bad as their destruction of raw data): namely the
>>>> suggestion that the very existence of warming or of the greenhouse
>>>> effect
>>>> is tantamount to catastrophe. This is the grossest of "bait and switch"
>>>> scams. It is only such a scam that lends importance to the machinations
>>>> in
>>>> the emails designed to nudge temperatures a few tenths of a degree.
>>>>
>>>> The notion that complex climate "catastrophes" are simply a matter of
>>>> the
>>>> response of a single number, GATA, to a single forcing, CO2 (or solar
>>>> forcing for that matter), represents a gigantic step backward in the
>>>> science of climate. Many disasters associated with warming are simply
>>>> normal occurrences whose existence is falsely claimed to be evidence of
>>>> warming. And all these examples involve phenomena that are dependent on
>>>> the confluence of many factors.
>>>>
>>>> Our perceptions of nature are similarly dragged back centuries so that
>>>> the
>>>> normal occasional occurrences of open water in summer over the North
>>>> Pole,
>>>> droughts, floods, hurricanes, sea-level variations, etc. are all taken
>>>> as
>>>> omens, portending doom due to our sinful ways (as epitomized by our
>>>> carbon
>>>> footprint). All of these phenomena depend on the confluence of multiple
>>>> factors as well.
>>>>
>>>> Consider the following example. Suppose that I leave a box on the
>>>> floor,
>>>> and my wife trips on it, falling against my son, who is carrying a
>>>> carton
>>>> of eggs, which then fall and break. Our present approach to emissions
>>>> would be analogous to deciding that the best way to prevent the
>>>> breakage
>>>> of eggs would be to outlaw leaving boxes on the floor. The chief
>>>> difference is that in the case of atmospheric CO2 and climate
>>>> catastrophe,
>>>> the chain of inference is longer and less plausible than in my example.
>>>>
>>>> Mr. Lindzen is professor of meteorology at the Massachusetts Institute
>>>> of
>>>> Technology.
>>>>
>>>>
>>>>
>>>>
>>>>
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>>>
>>>
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>>>
>>
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Received on Wed Dec 2 12:11:23 2009

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