http://tamino.wordpress.com/2010/02/16/growthgate/#more-2302

Suppose you have a child, a son — he’s 10. You want to know whether or not he’s growing normally, so every day you measure his height with a tape measure. You’ve done so since he was 5. You even plot the data on a graph, and notice two things about it. First: the measurements show a fair amount of jitter, sometimes they’re a wee bit higher, sometimes a wee bit lower, there’s noise in the data. Second: there’s also a trend. Your kid is a lot taller at 10 than he was at 5, in fact the trend over the observed time span is upward and reasonably steady. You even do a statistical analysis, estimate the growth rate, and determine that it’s definitely statistically significant — so it’s not a false trend due to noise in the data, it’s real. Your son is growing normally.

Then you’re interviewed by a reporter from the Daily Mail. He asks, “Can you prove — with statistical significance — that your child has been growing since last Tuesday?”

You reply that no, even though the trend over that time span is upward, it’s not statistically significant.

The next day you read the article in the Daily Mail which is titled, “Growthgate U-turn as parent admits: There has been no growth since last Tuesday.”

You protest. “I never said my child wasn’t growing! I just said that the data over such a short time span didn’t show it with statistical significance! That’s only because on such a short time scale, the noise obscures the trend.”

Alas, it’s too late, the damage is done, because 3500 blogs have repeated the article from the Daily Mail and child protective services has been asked to investigate your fitness as a parent.

Sound familiar?

"Climate is cooling according to Jones

The figure was 15 years, which relative to the (supposedly more) reliable temperature records and the period used for comparison with the CO2 emissions is no where near as short as your (linked to) comparison would suggest.

Here's the link to the article in the daily mail:

http://www.dailymail.co.uk/news/article-1250872/Climategate-U-turn-Astonishment-scientist-centre-global-warming-email-row-admits-data-organised.html

In particular:

The Global Warming™ cultists are grabbing at any straw they can now.  Man-made global warming has been exposed as the fraud it always was.

Agreed. However that's not any random 15 year period that's a specifically selected period (i.e. cherry picked) which shows a strong upward trend that just happens to be barely below the level of statistical significance.

Actually I'm surprised the questioner picked 1995 as the start date, most peole specifically pick 1998 as the start date since 1998 was a particularly strong El Nino year. However cherry picking is still cherry picking. If you choose 10 year intervals and then go back and check all such intervals over the last 30 or 40 years virtually all of them will show a statistically significant warming. Or pick 11 years, or 12 or any other interval and do the same thing and you'll find that the large predominance of all of them show significant warming. Of course there will be the occassional interval at specific start and end dates that won't be significant. Mostly these will still exhibit the warming trend just simply they will be slightly less than significant.

As far as the warming having stopped, enjoy the break while you can because this Janurary, you know the one with all the snow in Washington that "disproved GW", was in fact the warmest Janurary *ever* and this information is from deniers like Watts and Spencer.

http://climateprogress.org/2010/02/05/hottest-january-in-uah-satellite-record-roy-spencer-global-warming/

You could change the title of this thread from "Climate is cooling according to Jones" to "Climate is warming according to Spencer" and be equally honest.

The end (/start depending on which way you look at it) date isn't being cherry picked in this case though, it's just being taken from today/the most recent year which is what is typically done, so that means the only variable available for cherry picking is how long a period you look at, and the longer the period, the reduced likelihood of such cherry picking having a dramatic impact. That is, once you're looking at more than a 10 year period the effect of an additional year on the overall result will be reduced, thus limiting any attempts at cherry picking.

If say in the last 5-20 years (depending on the period being looked at) the only point at which there wasn't statistically significant warming was over a 15 year period then I could see the argument for cherry picking, but I doubt that is the case (I could be wrong, but I find it so hard finding climate figures from raw data that I can interpret next to impossible - I don't quite understand how I can find within a few seconds various graphs detailing the CO2 emissions per person by country and year, yet it's not easy to find a simple graph showing the average temperature per country per year. Then again it might just be that my searching methods aren't up to scratch)

Well one reason is that climate is *global* if you want details of a specific country what you're looking for is *weather*.

Even though the end date is today (actually 2009 as the most recent full year) that still doesn't make it random. If perhaps the most recent full year happened to be cooler than "average" for any particular reason then all trends ending in that year will appear to be lower than if that year was average. So both the start and end condition does come into play.

Here are two graphs demonstrating what we're talking about.

Clearly as you suggest the longer intervals have far fewer periods over the time period of interest that show any sort of decline, but that by no means suggests that all 15 year intervals are precisely equal or that a longer time interval regardless of start/end points is always a better measure, only that their variation is less.

Looking at the 15 year interval graph, the upward trend is pretty clear even though there are probably a number of lines whose slope happens to be slightly less than required to demonstrate a "statistically significant" upward trend. It's the totality of *all* the trendlines that conveys the complete information not just one line no matter how "fairly" that one particular line was selected and in the case of the questioner usually having an agenda that fairness is very often in doubt.

That's why most comparisons are made starting at 1998 and they make comments to the effect that global warming stopped in 1998. In this case they happened to back up the date a bit but isn't it convenient how that date is the next most recent maximum? Why didn't they back up the start to 1996 or 1994 or god forbid 1992 a local minimum? Because if they had they wouldn't get the result they want.

That's cherry picking.

Yep, it probably would not be easy since....

“In a January 29 report, they find that starting in 1990, the National Oceanic and Atmospheric Administration (NOAA) began systematically eliminating climate measuring stations in cooler locations around the world. Yes, that's right. They began eliminating stations that tended to record cooler temperatures and drove up the average measured temperature. The eliminated stations had been in higher latitudes and altitudes, inland areas away from the sea, as well as more rural locations. The drop in the number of weather stations was dramatic, declining from more than 6,000 stations to fewer than 1,500.”

 

 

Oh come on! Surely they wouldn't drop data that wold cause a different average measurement, would they?

 

Sheeple are such dumb creatures. Don't confuse them with pesky facts, it only upsets them.

Yeah, yeah. More garbage from Watts and D'Aleo, full of errors per usual.

Since you don't bother to provide any reference to this unnamed report I guess I'll have to do it for you.

The 111 page report itself is Surface Temperature Records: Policy Driven Deception? by Joseph D'Aleo and Anthony Watts, both infamous deniers with documented ties to ExxonMobil and whose expertise is pretty much limited to having been TV weathermen. Of course this is not a peer reviewed article nor would any reputable journal publish such drivel.

You can find the specific quote referenced all over the internet at literally hundreds of denier sites but the original is from Fox News (surprise, surprise), The Next Climate-gate?.

However if you wish to at least pretend to have an open mind you should read The IPCC vs. Joseph D'Aleo and Anthony Watts.

The following are but a few excerpts.

Meanwhile, lest we get the impression that the IPCC is the source of all, or even most, errors, a contrarian document has conveniently been published online.  It's called "Surface Temperature Records: Policy Driven Deception?" (pdf here) and it's by Joseph D'Aleo and Anthony Watts.  A reader asked me to comment on it.  It turns out to represent a refreshing change from the IPCC reports.  While it's necessary to dig and dig to find errors in the IPCC reports, the errors in what I'll call STR are right there on the surface, easy to spot.  Here's a sampling:

In paragraph 3, STR states: "First, there is a major station dropout and increase in missing data in stations that remained which occurred suddenly around 1990; about the time the global warming issue was being elevated to importance in political and environmental circles. A clear bias was found towards removing cooler higher elevation, higher latitude, and rural stations during this culling process though leaving their data in the base periods from which ‘averages’ and anomalies are computed."

But as the National Climatic Data Center has explained, there was no such culling process. Instead, the simple, non-sinister explanation is that some data sets are easily available electronically and some are not, and the more recent global data archived by NCDC only consists of the most easily accessible data streams. D'Aleo knows this; it's even quoted in his Icecap blog!  Incredibly, on page 60 he later refers to it as the "unexplained major station dropout" while nowhere in STR does he deign to mention that NOAA has offered a (logical) explanation.

In paragraph 10: "Calculating the average temperatures this way would ensure that the mean global surface temperature for each month and year would show a false-positive temperature anomaly – a bogus warming. This method would also ensure that the trend in the temperature change would be enhanced beyond the natural 60-year climate cycles."

D'Aleo and Watts are saying that because predominantly only warm stations are available in the data set in recent years, the temperature anomalies will be falsely positive and show a bogus warming. Their logic is absolutely wrong, and all major global temperature compilations (NCDC, GISS, and CRUTEM3) are calculated in such a way that a loss of stations like this doesn't bias the anomaly estimates.

The article goes on to explain precisely why their logic is absolutely wrong along with a few more examples of their errors but given that the "report" is just recently "published" there's sure to be more definitive shredding of this so-called work within the next few months. However given how the denialsphere works we can look forward to this same garbage being regurgitated years later, long after everyone already knows it's just a bunch of crap, just so that it may confuse the one or two people left that haven't already heard about it.

If you ever needed proof of the religion surrounding Global Warming, this is it.  If the science is so clear, they shouldn't be needing to distort, lie, and hide as they have been doing.

Then again, they are telling this to people who think Florida will be under water in 10 years.

But it does mean that it is much more likely to be a better measure, because of the reduced variation - if I was to take a random 7 period trend and a random 15 year trend and extrapolate that over say 20-30 years the 15 year period would be most likely to give the more accurate estimate.

Looking at that graph though they could have also gone to 90-91 and possibly achieved a similar result, making the cherry picking charge carry much less weight than if it was the sole year that could've been used. Thanks for providing the graph though.

Alright I guess I'm more interested in the (weather) temperature in each country each year then, since that seems of more relevance as the effects will be felt differently depending on the country/location, and also because I don't expect (although I could be wrong since I've pretty well no experience in the area) that a 1deg rise in global temperatures would cause temperatures to rise in every country by 1deg (all else equal). It'd also allow comparisons between the experiences of individual countries compared to what the global picture is saying. I'm sure the data must exist for at least some countries for a number of years but I don't seem able to find it.

First off I'm not a statistician, however I suspect that the "better measure" and "more accurate estimate" is not found by taking *one* random interval of *any* particular length but is found by a proper statistical analysis of the entire set of data, an analysis that I trust more to trained scientists in the field rather than to some random blogger with an agenda making unsupported statements.

You're welcome.

You're also right that there's more than one specific set of end points that could be chosen that would show less of an effect. However the bottom line is, is there an upward trend or isn't there? I look at the graph and there seems to me a pretty obvious upward trend regardless of whether someone has drawn in trendlines of any particular length or not.

Even those that disagree generally don't argue that there is no upward trend in that graph. Instead they argue that the datapoints themselves have been doctored or that if there is an upward trend it's not due to human activity or the graph shows that global warming stopped in 1998 or myriad other reasons (or excuses dependent on your point of view).

The thing is that a 1°C global average temperature rise really would not make one heck of a lot of difference to the weather of *any* country, at least directly. It's the indirect effects that are of concern. Like how much will sea levels rise based on that 1°C rise and what locales will be affected by that amount of sea level rise. Or how that 1°C rise will affect weather patterns over the globe and whether what was one countries breadbasket becomes a desert or not.

And if you were able to find the raw data that you're looking for then what? Do you really believe that with no obvious training that your interpretation of that data will be anywhere near as good as those that have studied in the field for years achieving specifically related advanced degrees that publish their results in peer reviewed articles in respected journals?

To me that's the problem with these so called skeptics. Too many arm chair quarterbacks that presume that they can do someone else's job better than well respected scientists with PhD's in specifically related fields.

If these people really were all that smart then they could prove it by publishing peer reviewed articles in respected journals either proving their point or disproving the real climate scientists. But they don’t, because they can’t.

Then go to here.

 

Agreed.

Sound like 'settled science' to you?

I'm sure they could get them published in the same journals that the IPCC relied upon for the Himalayan glacier, Amazon forest & Dutch drowning claims.  If they're good enough for the IPCC, should be good enough for you.

Why 'such a way'?

And the alarmists have no financial interests or disclosures to make.  Right.

AGW advocates are sure having to spend a lot of time 'denying' stuff lately.  Hard to tell the deniers from the Deniers.