

How I made the Met Office admit its climate-change data was wrong - prat
http://www.timesonline.co.uk/tol/news/uk/article7028418.ece

======
jgrahamc
Headline writers really like to create eye grabbing titles: I'd hardly call me
sending them a friendly email "making them admit" :-)

~~~
CWuestefeld
John, with a more technical audience here, can you describe what kind of
inconsistencies you found, and how your code was built to detect them? (I
mean, building consistency checks into code is easy; the art is in knowing
what kind of inconsistency those checks should be looking for)

~~~
jgrahamc
The average temperature between 1961 and 1990 (which is the critical baseline
for the anomaly charts that are drawn showing global warming) was incorrectly
calculated for a large number of stations (observing points) in Australia, New
Zealand and other parts of Oceania.

Each of the station files contains the observations from the station per year
and per month, as well as the calculated average (called the normal) and
standard deviation.

I was concerned that as I read and parsed the Met Office data I was make some
sort of standard cock-up like putting the wrong months in the wrong years so I
used the averages and standard deviations as a double check since they are
based on known date ranges.

BTW The code is open so you can stare at it yourself:
<http://landsurfacetemp.sourceforge.net/>

~~~
yannis
John, congratulations for the friendly email! (wondering actually who you
emailing next:) Glad to see a .pl making headlines! You obviously spent some
time with the data and I would appreciate it, if you can shed some light on
the 'average'. Does the average really represent a fair average over the
earth's surface? How is it exactly calculated? Are the met files raw data or
is it data that has gone through some homogeneity tests?

~~~
jgrahamc
I don't think I can really do your questions justice. I would suggest as a
first port of call the paper that describes how the Met Office generates
CRUTEM and HADCRUT.

Uncertainty estimates in regional and global observed temperature changes: a
new dataset from 1850 P. Brohan, J. J. Kennedy, I. Harris, S. F. B. Tett & P.
D. Jones <http://hadobs.metoffice.com/crutem3/HadCRUT3_accepted.pdf>

That paper is long and covers how the Met Office generates the trend data you
see, how the data is modified and gridded, how error estimates are generated,
etc.

~~~
yannis
Thanks

------
vannevar
Note that the article very clearly states at the beginning that the errors in
no way change the conclusion that the Earth is warming.

~~~
InclinedPlane
Sure. And none of the future climate-change revelations will overthrow the
conclusion that the Earth is experiencing relatively unprecedented warming.
Until the one that does (if that happens). Given the continuing flood of
revelations and the incestuous nature of this field (there is very little
truly independent data), the "consensus" 5 or 10 years from now may be quite
different from what it was 5 or 10 years ago.

------
albertcardona
While the article tells an interesting story and supports that climate change
is happening, the stone-throwing title suggests that something is wrong with
the idea of climate change. Very counterproductive.

------
kez
I read this in The Times this morning (made it it into the print copy), and
was surprised/pleased to see a HNer make it in).

Also relieved that the usually self-promotional jgrahamc didn't post the link
here himself.

~~~
jgrahamc
_Also relieved that the usually self-promotional jgrahamc didn't post the link
here himself._

I figured that you didn't need to hear me repeat a story that I've already
told here.

~~~
kez
Appreciated ; )

