How I made the Met Office admit its climate-change data was wrong | Hacker News Reader

How I made the Met Office admit its climate-change data was wrong

timesonline.co.uk

42 pointsprat15 comments

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

I was gong to comment "Did you skip the part about doing the work of trying to scientifically reproduce the results with the same data?" after down-voting.

I read your username after the vote. I would take it back, if I could, since it's your right to either be modest on the matter or if you really feel that all you did was "send them a friendly email". My apologies; I felt I owe an explanation since I was likely the first vote.

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)

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/

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?

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.

Thanks

I'm glad you commented wrt the title. This issue is already over-politicized and the Times seems to be stoking that fire when it needs dampening to make room for real discussion.

Yeah, really annoying headline.

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

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.

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.

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.

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.

Appreciated ; )

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