

Central England temperature dataset: 0.26°C increase per century since 1659  - dublinclontarf
http://blogs.telegraph.co.uk/news/jamesdelingpole/100022226/agw-i-refute-it-thus-central-england-temperatures-1659-to-2009/

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jgrahamc
Just go get HadCET yourself and do some analysis:
<http://hadobs.metoffice.com/hadcet/> I wouldn't listen to the rantings of The
Daily Telegraph, and specifically not this commentator:
<http://blogs.telegraph.co.uk/news/author/jamesdelingpole/>

OK. Downvote me then, but if you read the original blog post he's talking
about ([http://motls.blogspot.com/2010/01/warming-trends-in-
england-...](http://motls.blogspot.com/2010/01/warming-trends-in-england-
from-1659.html)) and you look at the '30 year bands' he's chosen they are
cherry picked. And he's saying 'Look here in 1661 or whatever it warmed faster
than it's warming now'. Seeing fast warming in central English in the past
doesn't disprove man-made global warming now.

If you dig into his Mathematica code and take a look at it you'll see a plot
he's made (which he doesn't blog about) that looks just like the global
warming trend plots everyone is putting out.

See: <http://imgur.com/K8Pcn.png>

Wonder why that doesn't get a mention?

~~~
dublinclontarf
Simply because you don't like him or the paper doesn't make them wrong.

And could you get a mirror for that post on blogspot for me, I live in China
and can't access it, cheers.

~~~
jgrahamc
_Simply because you don't like him or the paper doesn't make them wrong._

Agreed. But the underlying analysis for his article isn't a paper, it's a
random blog posting. The guys at the Met Office publish the actual data set
and they have put out papers based on them which are linked from their web
site. The HadCET dataset is referenced constantly in their other work.

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Tichy
If you hand pick your data set, you can probably show anything you want. I
remember reading about the stock market, that if you just shift the starting
and end points of "measurements" (for example about your fund's value), you
could always claim an x% increase over the last y years.

So this here is an interesting data point - but it really is just that.

I wouldn't be surprised if there were places on earth where temperatures have
been falling steadily, or have been rising or falling by extreme amounts.

~~~
paulodeon
I think the point is that this is simply the best dataset out there, it hasn't
been cherry-picked.

The only problem with this article is that there is no mention of how the
gulfstream could have had a stabilising effect.

The 30 year periods aren't cherry-picked either, they are picked because they
were the ones with the greatest increase in temperature.

~~~
Tichy
It seems to be one data set from one location. How can this be "the best data
set" out there? I don't think looking at one location is sufficient at all.

~~~
Retric
If you are going to measure a dataset by its completeness and its length you
are going to find it's the best based on that scale. However, if you want to
define some other scale which cares less about those factors and more about
geographic coverage feel free, but don't try to mix there definition with
yours because your "best" will be less compleat or cover a shorter period.

PS: If you feel some other dataset would be a better proxy feel free to argue
the point on its own merits. But be careful when you start to redefine the
terms someone else is using, it has little to do with their argument and is
not useful.

~~~
Tichy
I have nothing against the data set as such - I think it is great if such a
complete data set exists. All I am saying is that a data set from one location
is not sufficient to calculate the climate of the whole planet. It is one data
set among many, which happens to be especially complete.

------
ZeroGravitas
The linked blog lists the top ten tri-decades, ordered by temp rise. Here they
are in chronological order:

1687 - 1716, 4.333 °C/century

1688 - 1717, 4.7 °C/century

1689 - 1718, 4.446 °C/century

1690 - 1719, 4.754 °C/century

1691 - 1720, 5.039 °C/century

1692 - 1721, 4.642 °C/century

1694 - 1723, 4.524 °C/century

1977 - 2006, 4.95 °C/century

1978 - 2007, 5.038 °C/century

1979 - 2008, 4.705 °C/century

Can you see a pattern there?

So the first 7 are consecutive apart from skipping one year/tri-decade
(1693-1722) and the most recent three are 3 out of the last 4 years. And
indeed the 2nd, 3rd and 5th highest rise.

And yet the point he chooses to highlight directly after this list, is that
the most recent tri-decade (1980-2009) isn't in the (totally arbitrary cut off
point) top ten at all. It is however the 13th biggest rise. In other words 4
of the last 4 tri-decades are in the top 13 and at least 7 of the remaining 9
all are from consecutive periods starting 1687-1694.

Does this really show what he's suggesting it does? I'm not seeing anything
particularly useful drawn out by his analysis apart from records from around
the turn of the 17th century show a large drop followed by a large rise then
another massive, but short lived drop.

------
dublinclontarf
The link that the article is refering to:
<http://www.c3headlines.com/2010/01/cet-temperatures.html>

~~~
ZeroGravitas
The 30 year rises listed in that article, differ markedly from the other blog
by Lubos Motl, which he links to in support.

[http://motls.blogspot.com/2010/01/warming-trends-in-
england-...](http://motls.blogspot.com/2010/01/warming-trends-in-england-
from-1659.html)

What am I missing?

Can I also take this opportunity to point out the very dodgy choice of scales
on his first graph. The temperature data is limited to 1/7th of the height of
the graph, while the C02 changes are stretched to full height.

Graph here:
[http://c3headlines.typepad.com/.a/6a010536b58035970c0120a7c8...](http://c3headlines.typepad.com/.a/6a010536b58035970c0120a7c87805970b-pi)

The obvious impact of this is to downplay any shift in temperature in response
to changes in CO2 levels and any deviations from the linear trend line.

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yungchin
Just remember: you only measure what you measure. This data suggests that
Central England temperatures have only been slowly rising. It doesn't say
anything about average world temperatures.

(The Gulf Stream might be one of the reasons North-West Europe is a relative
stable point.)

I'd be interested to see similar plots from the Arctic.

------
benl
There's a lot of back-and-forth in this thread about whether this disproves
AGW or not.

Before people get too invested in these arguments, it might make sense to step
back for a second or two and ask yourself the question:

"What is the null hypothesis?"

As far as my understanding goes, in order to be doing good science, the null
hypothesis must be that there is no phenomenon to explain. So the qustion we
should be asking is: "is this evidence consistent with, or does it refute, the
null hypothesis?"

As far as I can tell, this evidence is consistent with the null hypothesis.
While that is interesting, it's not super-important, so we should all save our
passion and debating time for evidence that potentially refutes the null
hypothesis. That kind of evidence is much more important to find and pore
over...

* [edit] fixed a few typos

