Re: [asa] Data doesn't support global warming

From: Murray Hogg <muzhogg@netspace.net.au>
Date: Tue Dec 15 2009 - 12:45:48 EST

Hi Glenn,

That the homogeneity adjustments (i.e. "editing") are responsible for the difference between the raw and adjusted data is quite clear. The real question is whether those adjustments are reliable.

As you are no doubt aware, there is an extensive literature addressing that question, and the Peterson article from which you derived the graph is a part of that literature.

Now, I regret that this particular subject is so far outside my area of expertise such that there is doubtless an enormous amount of background knowledge one needs in order to make sense of Peterson's article. But I will venture on the following brief observation;

Peterson's methodology is essentially to compare the trends of adjusted data (for stations with known siting issues) and non-adjusted data (for stations with no known siting issues) by way of running a cross-check on the adjustments.

His conclusion;

<cite>
This analysis takes the opportunity afforded by the work of Davey and Pielke to evaluate not only the effects of poor station siting, but also the homogeneity adjustment techniques painstakingly developed over many years at the National Climatic Data Center. The results indicate that the work was not done in vain: the homogeneity adjustments did an excellent job of accounting for time-dependent biases at the stations examined and the homogeneity-adjusted data do not indicate any time-dependent bias caused by current poor station siting.
Peterson, Thomas C. “Examination of Potential Biases in Air Temperature Caused by Poor Station Locations.” Bulletin of the American Meteorological Society 87, no. 8 (August 2006), p.1080.
<http://ams.allenpress.com/archive/1520-0477/87/8/pdf/i1520-0477-87-8-1073.pdf>
</cite>

I short, am I not correct in thinking that Peterson's evaluation of the reliability of homogenity adjustments on data from poorly sited stations is somewhat at odds with your own?

I wonder if you have taken the time to bring your analysis to Peterson's attention, and what his response (if any) may have been?

Blessings,
Murray

> For Murray Hogg and Bill Powers
>
>>>> I wasn't actually arguing that your position is wrong, far less
>>>> conflating global circulation (is your keyboard broken?) models and
>>>> simple radiation escape. What I was doing was pointing out what I
>>>> thought the assumption might be.
>
> As regards explaining why everywhere but North America has cooled
> (presuming to be the case) - well, if it's so simple then I'd invite you
> to go ahead and explain it. "Miracle" is, remember, not an option.<<<<
>
> I think the explanation is that editing adds half a degree. If you take
> the final output of the GISS (Goddard) dataset and subtract from it the
> raw temperatures, you find that much of the supposed warming came merely
> from editing.
> This is that subtraction:
>
> http://1.bp.blogspot.com/_Lxqre8hMG3M/Sh7ntlYGwEI/AAAAAAAAAXY/9GQ6qdOqSEQ/s400/weatherRawVsSanitizedUStempDifferences.jpg
>
>
> It is from
> http://themigrantmind.blogspot.com/2009/05/homogeneity-how-fast-one-is-pulled-over.html
> which is worth a look at the homogeneity filter
>
> What that picture effectively says is that thermometers in 1900 were
> excellent and read temperatures spot on, but thermometers today read the
> temperature too cold and need warming up. Does anyone actually beleive
> this?
>
>
> For Bill Powers
>
>>> ) I know that this is a very "emotional" issue for you. <<<<
> First off, lets not be condescending. Condenscension does not help us
> stay focused on the facts and is beneath you. I am pugnacious as
> everyone knows.
>
>>>> You come into
> the room expecting to be stabbed in the back. So your adrenoline is
> running high and your responses sharp. Speaking only for myself, I am
> not fully persuaded of AGW. I've been skeptical for years because of my
> experience with running and developing complex physics codes. But I am
> listening and learning from others. You come armed with a quiver full
> of arrows. So your situation is different. I only council that you not
> presume everyone is attacking you or your positions.<<
>
> I challenge anyone and anything, including those who say things wrong
> who support my position. I have no idea what you beleive about AGW
> because I have no experience discussing it with you.
>
>
>>>> 2) It seems to me that the albedo issue is important for global climate
> warming. With global albedo measurements, we can estimate the amount of
> energy that is being absorbed by the terrestrial system. This, however,
> does not immediately translate into temperatures. In order to translate
> this into global temperatures we would need an estimate of global heat
> capacity, which likely will change with a changing terrestrial
> environment. Nonetheless, albedo measurements are an independent and
> global measurement that can support global climate change. Whether CO2
> is essentially responsible for the change in albedo is a secondary
> question.<<<
>
> While I agree with this, I would point out that the heat capacity of
> dirt and air is not changing with time, so I can't figure out how you
> think that the heat capacity changes with a change in terrrestrial
> environment.
>
>>>
> 3) From what you have said, apparently in opposition to what I have
> said, I take it that we are in agreement, i.e., my attempts to summarize
> (in part) what you are saying have been confirmed by your responses, which
> is only to say that either I said it badly or that you misunderstood what
> I was saying.<<<
>
> It didn't sound like a correct summary to me. In fact it didn't sound
> like a summary to me but I will take your word for it.
>
>
>>>> To be more explicit, you believe that the temperature data has
>>>> significant
> variance. This is, of course, not something new. I was simply rehearsing
> how science has tried to deal with such problems, both statistically and
> by seeking "independent" confirmation.<<<
>
> Yes, the variance and noise in the data is very high; much higher than
> the proclaimed warming.
>
>>>>> I would suggest that you indicate by what means we might resolve the
> problem. What would you do to determine whether there is global warming,
> and at what rate?<<<
>
> We need to build a worldwide set of temperature stations that actually
> match the siting recommendations--thermometers not on cement or roof
> tops, not within 10 meters of heat emitting buildings, etc., and for
> petes sake not next to air conditioner exhaust fans. Even rural areas
> are hampered by that. Riverton Wyoming, where I started my geophysical
> career years ago has 2 air conditioner exhausts near their thermometer.
> Riverton Wyoming:
>
> http://4.bp.blogspot.com/_Lxqre8hMG3M/Sq1_VmjCpiI/AAAAAAAAAlQ/zHd5inydsss/s400/weatherWYRiverton_closeup_95-97_airconditionera.jpg
>
>
> St. Ignatius MT (another rural area)
> http://3.bp.blogspot.com/_Lxqre8hMG3M/Sq1-1FMr53I/AAAAAAAAAlI/GcvI9h3iZ9M/s400/St_Ignatius_AC_discharge.jpg
>
>
> Urbana OH
> http://2.bp.blogspot.com/_Lxqre8hMG3M/Sq1-UFgmF2I/AAAAAAAAAlA/JFDN1f0QzlM/s400/weatherOHUrbanaThermometer.JPG
>
>
> 69% of thermometers in the US are next to heat sources like this. And
> people believe the temperature they give is indicative of the climate.
> What a laugh.
>
> I would like to see what Randy and Rich think of putting a thermometer
> in such settings. Specifically how do they think they can correct the
> temperature output from such a thermometer when no records are kept of
> when the AC is on?
>
> I really do wish the ASA would get a modern forum software where
> pictures can be posted rather than linked to.
>
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Received on Tue Dec 15 12:46:22 2009

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