Saturday
Jun082013
by 
Bishop Hill
Bishop Hill A lucky escape for Roy Spencer
Jun 8, 2013 Climate: Surface Roy Spencer's recent post comparing climate model predictions to observations has been providing lots of entertainment in recent days - I really should have posted a link before. David Appell is unamused by Roy's thoughts though, and has taken him to task,declaring his blog post "unprofessional". He also has an interesting point to make about Roy's UAH temperature record:
But then there is this: the linear trend for the entirety of the two datasets on middle tropospheric temperatures in the tropics is
RSS MT 20S-20N: 0.090 ± 0.028 °C/decadeUAH MT 20S-20N: 0.030 ± 0.028 °C/decade
That's right -- their trends differ by a factor of three, with UAH by far the lowest -- a fact which is neatly hidden away in Spencer's graph by taking their average.
Just as well Roy didn't come up with a trend of zero eh?
Reader Comments (110)
@Entropic Man
The reduced Arctic ice extent you reference occured at the peak of the current interglacial, when the forcing due to favourable Milankovich effects was at its peak and temperatures were similar to today's. We are well into the subsequent decline from that peak. Natural variation is generating negative forcing effects which should be pushing both temperature and CO2 lower. There are no natural mechanisms to explain the current long term reversal of that downward trend.
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There are several issues here:
You are wrong, the Milankovich cycle is no longer declining. we are around a bottom right now.
As such bottoms are round and flat, there will not be much change in the next decades nor has there been much difference between now and the Medieval Warm Period, when global temperatures were at least as warm as today.
(I will not spend time with Mann or Marcott style hockey sticks on a quality website like this, if you had those in mind.)
So, there is still plenty of upside room until we reach the temperatures of the Climate Optimum a few thousand years ago.
The issue then turns the other way: we could explain the current rise with GHG and the little ice age with volcanic eruptions, but we cannot explain the Medieval Warm Period.
Except if we assume an unknown natural variation of considerable size that is just dormant or undiscovered today.
But there is a better explantion out there, with spectacular correlation not only for each and every major up and down during the last 11 thousand years including the MWP, the little ice age and at least part of the modern warm period.
There is no such correlation of any other 2 climate variables in climate science:
Bond et al 2001, Persistent Solar Influence on North Atlantic Climate During the Holocene
http://kaltesonne.de/wp-content/uploads/2012/05/bond-et-al-2001.gif
David Appell, if you're man enough answer John's questions. If not you're the one who are a lying coward making untrue assertions.
Ha -- nice try. Tell John (Christy?) to man up.
John has clearly said he's not John Christy. You've proven that you are gutless by not answering the questions raised by him. You come, slime and run away like a typical lying warmist.
When John (Christy?) finds the courage to ask using his real name, I will find the courage to answer him.
I've been trying to locate a blog which I was following recently where a character calling himself DavidA persistently refused to answer points that were put to him.
On that site his excuse was that his interlocutors were refusing to provide him with the references he was demanding.
I must say the word "troll" did come to mind a couple of times.
All Appell's bluster about anonymity and professionalism is just a smokescreen. I asked him before, and I'll ask him again now:
Does his answer to a question depend upon the identity of the person asking?
"There are no questions in "John's" comment,"
That's odd, you seemed to understand what he was asking earlier....
""John": Reveal your identity and I'll answer your questions."
There were definitely a set of questions at the end of my post you still haven't answered.....
> Nial: There is precedence for a discrepency between modeled and measured
> tropospheric temperatures being resolved in favor of the models:
From Spencer's article...
"Note that the observations (which coincidentally give virtually identical trends) come from two very different observational systems: 4 radiosonde datasets, and 2 satellite datasets (UAH and RSS)."
If this does need correction what do you estimate that to be?
When that's taken into account, how far away from reality will the 'model' results still be?
Will you stand back and look at the big picture?
Niall,
There's no limit to the levels to which this **** can sink to. You've caught him lying right here.
> There's no limit to the levels to which this **** can sink to. You've caught him lying right here.
Strictly speaking he isn't lying as there _aren't_ any questions in John's initial post.
There are a series of points which he has weasled out of addressing.