BBC spørger, hvad der skete med den globale opvarmning
This headline may come as a bit of a surprise, so too might that fact that the warmest year recorded globally was not in 2008 or 2007, but in 1998.
But it is true. For the last 11 years we have not observed any increase in global temperatures.
And our climate models did not forecast it, even though man-made carbon dioxide, the gas thought to be responsible for warming our planet, has continued to rise.
So what on Earth is going on?
Den undren afhænger jo kun af ens forventninger og med hensyn til klimaet afhænger de forventninger af de, der gejler dem op, som Christopher Booker beskriver i Telegraph
Everyone has enjoyed the discomfiture of the Met Office, caught out over its April forecast that we were in for a “barbecue summer” – not least because this is the third year running that our weathermen have got their predictions for both summer and winter hopelessly wrong. In 2007 and 2008 they forecast that summers would be warmer and drier, and winters milder than average – just before temperatures plunged and the heavens opened, deluging us with abnormal rain or snow according to season.
One cause of the blunders that have made the Met Office a laughing stock is less widely appreciated, however. It is that the multi-million pound computer it uses to assist its short-term forecasting for Britain is also one of the four main official sources of data used by the UN’s Intergovernmental Panel on Climate Change (IPCC) to predict global warming. In this respect the IPCC’s computer models have proved just as wrong in predicting global temperatures as the Met Office has been in forecasting those mild winters and heatwave summers.
Måske skal man derfor anse det for en helgardering at “…last month Mojib Latif, a member of the IPCC (Intergovernmental Panel on Climate Change) says that we may indeed be in a period of cooling worldwide temperatures that could last another 10-20 years.” ifølge BBC? Men tilbage til Booker i Telegraph
In recent months, in fact, a curious little drama has been unfolding over attempts by Steve McIntyre, a Canadian statistical expert, to get the Met Office and the CRU to divulge the computer data on which they base their temperature record. Mr McIntyre was not only the chief demolisher of the “hockey stick”, showing how it was based on a seriously skewed computer model, but later exposed the “adjustments” which had skewed the other official record of surface temperatures, run by Dr James Hansen of the Goddard Institute for Space Studies. (The two other official sources of temperature data are based on satellite measurements.)
When Mr McIntyre made Freedom of Information requests to see the data used to construct the HadCrut record (as he has chronicled on his ClimateAudit blog) he was given an almighty brush-off, the Met Office saying that this information was strictly confidential and that to release it would damage Britain’s “international relations” with all the countries that supplied it.
Den historie gør Patrick J. Michaels mere ud af og spøger om hunden har spist den globale opvarmning. Det man får ud af en computer afhænger jo af det man kommer ind i den. Og udover de mange teorier om hvad, der på virker, hvad i, hvilken grad er der også noget så simpelt som rå data - og dem er der mange af. For at danne sig et overblik over udvikling og processer er man nødt til at vide noget om det historiske klima og her har årringe traditionelt spillet en stor rolle - også for IPCC, som The Register kan fortælle
In particular, since 2000, a large number of peer-reviewed climate papers have incorporated data from trees at the Yamal Peninsula in Siberia. This dataset gained favour, curiously superseding a newer and larger data set from nearby. The older Yamal trees indicated pronounced and dramatic uptick in temperatures.
How could this be? Scientists have ensured much of the measurement data used in the reconstructions remains a secret - failing to fulfill procedures to archive the raw data. Without the raw data, other scientists could not reproduce the results. The most prestigious peer reviewed journals, including Nature and Science, were reluctant to demand the data from contributors. Until now, that is.
At the insistence of editors of the Royal Society’s Philosophical Transactions B the data has leaked into the open - and Yamal’s mystery is no more.
From this we know that the Yamal data set uses just 12 trees from a larger set to produce its dramatic recent trend. Yet many more were cored, and a larger data set (of 34) from the vicinity shows no dramatic recent warming, and warmer temperatures in the middle ages.
In all there are 252 cores in the CRU Yamal data set, of which ten were alive 1990. All 12 cores selected show strong growth since the mid-19th century. The implication is clear: the dozen were cherry-picked.
Controversy has been raging since 1995, when an explosive paper by Keith Briffa at the Climate Research Unit at the University of East Anglia asserted that that the medieval warm period was actually really cold, and recent warming is unusually warm. Both archaeology and the historical accounts, Briffa was declaring, were bunk. Briffa relied on just three cores from Siberia to demonstrate this.
Three years later Nature published a paper by Mann, Bradley and Hughes based on temperature reconstructions which showed something similar: warmer now, cooler then. With Briffa and Mann as chapter editors of the UN’s Intergovernmental Panel on Climate Change (IPCC), this distinctive pattern became emblematic - the “Logo of Global Warming”.
Mann too used dendrochronology to chill temperatures, and rebuffed attempts to publish his measurement data. Initially he said he had forgotten where he put it, then declined to disclosed it. (Some of Mann’s data was eventually discovered, by accident, on his ftp server in a directory entitled ‘
Tree data was secondary in importance to Mann’s statistical technique, which would produce a dramatic modern upturn in temperatures - which became nicknamed the “Hockey Stick” - even using red noise.
I det hele taget er årringe en velbevaret hemmelighed ifølge Doug Keenan.
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