[LMB] CO2 - Re: Butter Bugs! Well, almost.... OT:

Mark Allums mark at allums.com
Fri Jun 27 05:05:11 BST 2008


Here's a top post (for obvious reasons), from the list's resident 
hypocrite.

Good post, Paula.

However, I do not agree with the computer modeling.  It is a circular 
logic.  They program the computer to simulate the model they have agreed 
upon, thus, the results of modeling agree with the conclusions they have 
already agreed to reach, and then they program the computer to better 
approximate those results, and so on, ad infinitum.

Also, GIGO, which I am sure you know what means.

Mark Allums



Paula Lieberman wrote:
> ----- Original Message ----- 
> From: "Mark Allums" <mark at allums.com>
> To: "Discussion of the works of Lois McMaster Bujold." 
> <lois-bujold at lists.herald.co.uk>
> Sent: Thursday, June 26, 2008 9:02 PM
> Subject: Re: [LMB] CO2 - Re: Butter Bugs! Well, almost.... OT:
> 
> 
>> Greg Hennessy wrote:
>>> On Thu, Jun 26, 2008 at 2:53 PM, Mark Allums <mark at allums.com> wrote:
>>>> There is something that a lot of people overlook.  CO2 is not really a
>>>> greenhouse gas, Al Gore notwithstanding.  The main greenhouse gas is
>>>> water vapor, with methane running a distant second.
>>> What does it mean to be "not really" a greenhouse gas?
>>> Does it mean you argue it isn't, but when challenged
>>> you concede it is one?
>>>
>> I have read, and I believe, and I will look up a reference if necessary,
>> that CO2 is responsible for about 2% of warming, and water vapor, about
>> 95%.  Methane, fluorocarbons, and other things, the other 3%.
> 
> From
> 
> http://www.realclimate.org/index.php/archives/2006/11/supreme-court-amicus-curiae-from-scientists/
> - begin quote of Covey email --
> 
> Dear Prof. Battisti,
> 
> Part of my job here at LLNL is to accurately communicate the results of
> my work to scientific colleagues and the public. Accordingly, you
> should feel free to share the comments below.
> 
> Page 11 of the brief begins, "As shown below, computer models predicting
> future warming must overestimate warming, because they generally use an
> incorrect increase in carbon dioxide concentration of 1% per year." It
> is not true that models "generally use" this rate of increase. Model
> simulations of 20th century global warming typically use actual observed
> amounts of atmospheric carbon dioxide, together with other human (for
> example chloroflorocarbons or CFCs) and natural (solar brightness
> variations, volcanic eruptions, .) climate-forcing factors. Model
> simulations of future global warming use analogous input; of course it
> is not possible to observe the future, so a variety of scenarios
> involving possible atmospheric concentrations of carbon dioxide, etc.,
> are employed. These range from stabilization of atmospheric carbon
> dioxide at twice its pre-industrial value by the end of this century
> (IPCC SRES B1) to continuously increasing atmospheric carbon dioxide at
> the rate of a bit less than 1% per year (IPCC SRES A2). Each climate
> model simulating the future is run several times, with several different
> scenarios. All of this has been standard practice in climate modeling
> for the past ten years.
> 
> Pages 11-12 quote my 2003 review paper correctly regarding idealized
> simulations in which atmospheric carbon dioxide is assumed to increase
> at the precise rate of 1% per year. Note that in the end of the quoted
> passage, I say that this rate of increase could "perhaps" be considered
> realistic "as an extreme case in which the world accelerates its
> consumption of fossil fuels while reducing its production of
> anthropogenic aerosols." I'm no expert on scenarios, but from what I
> hear about China and India I wonder if the world is already on that
> track. In any case, the purpose of the 1%-per-year scenarios is to
> compare different models' responses to identical input - not to produce
> realistic possibilities of future climate. For the latter purpose,
> climate model output from the IPCC SRES B1, A2 and other scenarios has
> been widely used for several years and has been publicly available for
> over two years on my group's Web site at
> http://www-pcmdi.llnl.gov/ipcc/about_ipcc.php.
> 
> Finally it is not true, as implied on Page 12, that "sole reliance on
> models to the exclusion of observed behavior" is the basis of future
> climate prediction. As noted above, modern climate models are used to
> retrospectively simulate the 20th century as well. Simulation of 20th
> century global warming is an important confidence-builder for climate
> models. Indeed, the observed warming during the 20th century cannot be
> explained other than by assuming that the models are reasonably accurate
> in their response to greenhouse gases. This point was clearly made by
> the IPCC report published in 2001. Pages 12-13 ignore all this and
> instead use "a constant-rate warming" of 1.8 degrees C per century
> "based on actual observations." A constant-rate (i.e. straight-line)  [*]
> extrapolation of global warming from the 20th to the 21st century, as in
> the brief's Figure 2, is a favorite technique of one of the authors, Pat
> Michaels. This technique gives 21st century warming at the low end of
> the spectrum of possibilities resulting from the different model-input
> scenarios. It is one possible future, but it's never been clear to me
> (or to anyone else I know besides Pat) why the other possibilities -
> all of which involve more global warming - should be ignored.
> 
> Sincerely,
> Curt Covey
> 
> ====================================
> 
> What Curt was indicating I expect is that a  straight line extrapolation is 
> a bad model/extrapolation to use--China, India, etc., have been increasing 
> their output of COx nd NOx and such, so using a straight line approximation, 
> results in considerable underestimates.
> 
> Note--I saw Curt last year at a dormfloor reunion, I've known him since my 
> freshman year of college...




Mark Allums



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