wondering if this is sign of bias toward warming reporting in the media … bear with me.

google trends reports US news mentions (second graph) for “record high temperature” stomp over news mentions of “record low temperatures” over the last few years.

http://trends.google.com/trends?q=record+low+temperature%2C+record+high+temperature&ctab=0&geo=us&geor=all&date=all&sort=1

this despite the fact that no state has reported a record high temperature since 1995, according to infoplease/NCDC/StormFax:

http://www.infoplease.com/ipa/A0001416.html

not really statistically savvy enough to know if a 14-year gap (1995-2009) is a long time to go without a record high in at least one state out of 50 … the previous gaps were 11 years (’83-’94), 8 years (’75-’83) and 14 years (’61-’75). but that’s beside the point.

why would the media report more about record highs than record lows during a period when there were apparently few record highs set?

presumably the record high reporting was not about US states, but rather about other countries or perhaps individual towns within the US, which could obviously have their own record highs without affecting the respective state’s record high. so a little more research is in order here. would be interesting to see whether there were more record highs than record lows in US towns and cities over the last few years (the period google trends tracks).

Your 15:10 post on the 28th shows quasi-gaussian temperature readings at Bergen for a month. My earlier comment about likely non-normality, however, concerned the daily MAXIMA, whose EXTREME values result in RECORDS. Not the same thing at all.

The mechanism by which you infer the odds year-on-year of a temperature being a record high or low is fundamentally flawed.

The post by “Phil.” at 21:42:12 on 28 Apr 09 explains the reasons why.

You need to re-calculate the expected number of broken records taking Phil’s comments into account.

This number will be lower than your initial calculations, which suggests to me that record highs and lows have more significance as climate “events”.

I still think the hypothesis that more high records should be broken than low records in a warming climate is valid. The question is, what is the likelihood of such an occurrence in your scenario’s stable climate? Only than can we assess the significance of actual measurements.

I feel you do good work, Steven, but I think this article was insufficiently rigorous.

I’m not arguing that climate change is normal. I’m arguing that climate change occurs.

“You’re saying that “everyone knows” that climate change is normal or at least happens normally…”

I’m not saying that. Here’s what I said: “…nothing in the data or the way it is presented implies a past “perfect unchanging climate”.

I’m arguing that people, including AGW supporters, know that climate change occurs. That’s not the same as “normal”. My argument was in response to the claim that AGW people “imagine” that in the past there was a “perfect unchanging climate”. The relevant issue here is “change”, not “normal”.

“They” say…Climate’s been so “perfectly unchanging” over the last couple thousand years…”

Who are “they”? I have heard the climate of the past two thousand years described as stable, but that’s not the same as “perfectly unchanging”.

“…you are continuing to defend the irresponsibly stated “PANIC!”

I don’t defend irresponsible panic-mongering. People have differing views on the likely outcomes of AGW, so there will be a range of opinions. And of course AGW sceptics often appeal to lurid scenarios of mass death and misery from measures to mitigate AGW. So the panic swings both ways.

Yes, absolutely. Any claim that there is a systematic cooling trend should be met with the same degree of rational skepticism as a claim of systematic warming.

Also, the argument applies equally well to record low temperatures, so all the record lows we see are just what would be expected from random data [as per the argument].

Steve Goddard has presented a plausible first pass at a null hypothesis for testing the claim that the number of observed record temperatures is unexpectedly large due to a systematic drift in climate. Perhaps the model could be refined to add year-to-year autocorrelation such that the April 28 high temperature at a given location is not merely a Gaussian random variable but the result of a Brownian walk.

But in any case, statistically testing assertions against a null hypothesis such as the one Steve presented is essential to validating any GW or AGW claims. If the AGW camp cannot show at, say, the 95% confidence level that the number of observed new highs is inconsistent with a stationary (or randomly drifting) climate hypothesis, then we can rightly dismiss their claims out of hand.

Personally, I think the evidence indicates that there indeed has been a systematic upward temperature trend over the past 100 years (even after accounting for likely bad data from many surface stations). But I would like to see the p-value for a test of this claim. And even if there is GW, that does not mean it’s AGW.

(BTW, the posted C++ code appears to use uniformly distributed random variables rather than Gaussian ones.)

Given the number of April’s since measurements began there was ~ 0.5% chance of this happening this year.

I couldn’t find the daily data for that site but based on the April monthly data and assuming a Gaussian distribution there would be a 0.3% chance of the previous record being broken (-10ºC) and ~0.02% chance that it would be below -13ºC. Goddard’s method would say that there was a 1/79 (1.3%) chance of being a record.

No-one imagines such a thing.

In fact your argument works against you. When ice ages are brought up they are used for the “climate change is bad” argument, NOT that climate change is normal, which again is the opposite of what your argument relies upon.

“They” say:
“Just a few degrees below “normal” and we have an ice age. Now look at the Mann Hockey Stick. See! Climate’s been so “perfectly unchanging” over the last couple thousand years [after completely jury rigging the data to make the MWP, LIA, etc. disappear - as clearly detailed again and again in ever increasing detail here and over at Climate Audit]. Now the Mann figure shows us we’re heading for a few degrees above “normal” [if I just draw a connect-the-dots line between the last two data points and extend it into the future in a highly scientific way] so the sky is falling again!”

You’re saying that “everyone knows” that climate change is normal or at least happens normally, but that is NOT what is being presented by either the anthropogenic warming proponents or the media in general. And as more and more data shows that the northern sea ice continues to both expand in area and thickness when compared year to year (see yesterday’s posting of German measurements of polar sea ice thickness) and at BOTH poles you are continuing to defend the irresponsibly stated “PANIC! The North Pole may be ice free this year!” article at the beginning of this post. (BTW, that’s hyperbole to make a point.)

And, again, while all this is happening the exceptionally UNSCIENTIFIC Catlin party is sending out, “gee, the ice is really THIN here!” releases and the NSIDC (who’s that incoming Director?) is supporting their work. So where are the straw men, really?

Charlotte Pass, NSW, Australia today broke the all time low record in Australia for the month of April with a chilly start of -13 degrees C.

Given the number of April’s since measurements began there was ~ 0.5% chance of this happening this year.

The intro to the article reads: “Consider a hypothetical country with 1,000 top notch weather stations and the perfect unchanging climate…”

From this description, the argument certainly appears to involve an unchanging climate, and at (07:05:00) Steve Goddard says: “This is exactly how the temperature distribution would behave in a stable climate”.

However, I take your point that the substantive argument does not require an unchanging climate. But that still leaves the section in parantheses: “…(which our AGW friends imagine used to exist before they were born.)”. The “which” in this case refers to “perfect unchanging climate”.

And that is a straw man, since AGW makes no such claim. The argument is implied by the use of a snide term such as “imagine”. In other words: ‘AGWers think that past climate was perfectly unchanging, but of course they’re dreaming, no such climate has existed.’

I didn’t say our way of life would be “shattered”. That aside, a 2 deg C rise is at the lower end of IPCC projections, with a high of around 6 deg C. The higher levels would definitely cause a disruption to our way of life (ie to a society with a complex economy based on a high degree of interdependence).

So? The best straw men are hyperbolic. (By the way, I’m referring to the article that heads this thread, by Steven Goddard.)

“…that the way the data is presented to the general public it would be virtually impossible for the public to not draw that conclusion.”

As far as I can see, nothing in the data or the way it is presented implies a past “perfect unchanging climate”. And as for the public drawing conclusions, ice ages are common knowledge so I doubt anyone infers a past static climate from AGW.