Skewed sci­ence

A French sci­en­tist’s tem­per­a­ture data show re­sults dif­fer­ent from the of­fi­cial cli­mate sci­ence. Why was he stonewalle­d?

National Post (Latest Edition) - - FP COMMENT - IL GR EEN

The global av­er­age tem­per­a­ture is cal­cu­lated by cli­ma­tol­o­gists at the Cli­matic Re­search Unit (CRU) at the Uni­ver­sity of East Anglia. The tem­per­a­ture graph the CRU pro­duces from its monthly aver­ages is the main in­di­ca­tor of global tem­per­a­ture change used by the In­ter­na­tional Panel on Cli­mate Change, and it shows a steady in­crease in global lower at­mo­spheric tem­per­a­ture over the 20th cen­tury. Sim­i­lar graphs for re­gions of the world, such as Europe and North Amer­ica, show the same trend. This is con­sis­tent with in­creas­ing in­dus­tri­al­iza­tion, grow­ing use of fos­sil fu­els, and ris­ing at­mo­spheric con­cen­tra­tions of car­bon diox­ide.

It took the CRU work­ers decades to as­sem­ble mil­lions of tem­per­a­ture mea­sure­ments from around the globe. The ear­li­est mea­sure­ments they gath­ered came from the mid 19th cen­tury, when mariners threw buck­ets over the side of their square rig­gers and hauled them up to mea­sure wa­ter tem­per­a­ture. Me­te­o­rol­o­gists in­creas­ingly started record­ing reg­u­lar tem­per­a­ture on land around the same time. To­day they col­lect mea­sure­ments elec­tron­i­cally from na­tional me­te­o­ro­log­i­cal ser­vices and ocean-go­ing ships.

Mil­lions of mea­sure­ments, global cov­er­age, con­sis­tently ris­ing tem­per­a­tures, case closed: The Earth is warm­ing. Ex­cept for one prob­lem. CRU’s av­er­age tem­per­a­ture data doesn’t jive with that of Vin­cent Cour­tillot, a French geo-mag­neti­cist, di­rec­tor of the In­sti­tut de Physique du Globe in Paris, and a for­mer sci­en­tific ad­vi­sor to the French Cab­i­net. Last year he and three col­leagues plot­ted an av­er­age tem­per­a­ture chart for Europe that shows a sur­pris­ingly dif­fer­ent trend. Aside from a very cold spell in 1940, tem­per­a­tures were flat for most of the 20th cen­tury, show­ing no warm­ing while fos­sil fuel use grew. Then in 1987 they shot up by about 1 C and have not shown any warm­ing since. This pat­tern can­not be ex­plained by ris­ing car­bon diox­ide con­cen­tra­tions, un­less some crit­i­cal thresh­old was reached in 1987; nor can it be ex­plained by cli­mate mod­els.

Cour­tillot and Jean-Louis Le Mouël, a French geo-mag­neti­cist, and three Rus­sian col­leagues first came into cli­mate re­search as out­siders four years ago. The Earth’s mag­netic field re­sponds to changes in so­lar out­put, so ge­o­mag­netic mea­sure­ments are good in­di­ca­tors of so­lar ac­tiv­ity. They thought it would be in­ter­est­ing to com­pare so­lar ac­tiv­ity with cli­matic tem­per­a­ture mea­sure­ments.

Their first step was to as­sem­ble a data­base of tem­per­a­ture mea­sure­ments and plot tem­per­a­ture charts. To do that, they needed raw tem­per­a­ture mea­sure­ments that had not been av­er­aged or ad­justed in any way. Cour­tillot asked Phil Jones, the sci­en­tist who runs the CRU data­base, for his raw data, telling him (ac­cord­ing to one of the ‘Cli­mate­gate’ emails that sur­faced fol­low­ing the re­cent hack­ing of CRU’s com­puter sys­tems) “there may be some quite im­por­tant in­for­ma­tion in the daily val­ues which is likely lost on monthly av­er­ag­ing.” Jones re­fused Cour­tillot’s re­quest for data, say­ing that CRU had “signed agree­ments with na­tional me­te­o­ro­log­i­cal ser­vices say­ing they would not pass the raw data onto third par­ties.” (In­ter­est­ingly, in an­other of the CRU emails, Jones said some­thing very dif­fer­ent: “I took a de­ci­sion not to release our [me­te­o­ro­log­i­cal] sta­tion data, mainly be­cause of McIn­tyre,” re­fer­ring to Cana­dian Steve McIn­tyre, who helped un­cover the flaws in the hockey stick graph.)

Cour­tillot and his col­leagues were forced to turn to other sources of tem­per­a­ture mea­sure­ments. They found 44 Euro­pean weather sta­tions that had long se­ries of daily min­i­mum tem­per­a­tures that cov­ered most of the 20th cen­tury, with few or no gaps. They re­moved an­nual sea­sonal trends for each se­ries with a three-year run­ning av­er­age of daily min­i­mum tem­per­a­tures. Fi­nally they av­er­aged all the Euro­pean se­ries for each day of the 20th cen­tury.

CRU, in con­trast, cal­cu­lates av­er­age tem­per­a­tures by month — rather than daily — over in­di­vid­ual grid boxes on the Earth’s sur­face that are 5 de­grees of lat­i­tude by 5 de­grees of lon­gi­tude, from 1850 to the present. First it makes hun­dreds of ad­just­ments to the raw data, which some­times re­quire ed­u­cated guesses, to try to cor­rect for such things as changes in the type and lo­ca­tion of ther­mome­ters. It also com­bines air tem­per­a­tures and wa­ter tem­per­a­tures from the sea. It uses fancy sta­tis­ti­cal tech­niques to fill in gaps of miss­ing data in grid boxes with few or no tem­per­a­ture mea­sure­ments. CRU then ad­justs the aver­ages to show changes in tem­per­a­ture since 1961-1990.

CRU calls the 1961-1990 the “nor­mal” pe­riod and the av­er­age tem­per­a­ture of this pe­riod it calls the “nor­mal.” It sub­tracts the nor­mal from each monthly av­er­age and calls th­ese the monthly “anom­alies.” A pos­i­tive anom­aly means a tem­per­a­ture was warmer than CRU’s nor­mal pe­riod. Fi­nally CRU aver­ages the grid box anom­alies over re­gions such as Europe or over the en­tire sur­face of the globe for each month to get the Euro­pean or global monthly av­er­age anom­aly. You see the re­sult in the IPCC graph nearby, which shows ris­ing tem­per­a­tures.

The de­ci­sion to con­sider the 1961-1990 pe­riod as ‘nor­mal’ was CRUs. Had CRU cho­sen a dif­fer­ent pe­riod un­der con­sid­er­a­tion, the IPCC graph would have shown less warm­ing, as dis­cussed in one of the Cli­mate­gate emails, from David Parker of the UK me­te­o­ro­log­i­cal of­fice. In it, Parker ad­vised Jones not to se­lect a dif­fer­ent pe­riod, say­ing “anom­alies will seem less pos­i­tive than be­fore if we change to newer nor­mals, so the im­pres­sion of global warm­ing will be muted.” That’s hardly a com­pelling sci­en­tific jus­ti­fi­ca­tion!

It is well known to statis­ti­cians that in any but the sim­plest data sets, there are many pos­si­ble ways to cal­cu­late an in­di­ca­tor us­ing aver­ages. Para­dox­i­cally, and counter-in­tu­itively, they of­ten con­tra­dict each other. As a sim­ple ex­am­ple of how the same data can be teased to pro­duce di­ver­gent re­sults, con­sider the bat­ting aver­ages of David Jus­tice and Derek Jeter. For each of three years in 1995-97, Jus­tice had a higher bat­ting av­er­age than Jeter did. Yet, over­all, Jeter had the high­est bat­ting av­er­age.

In ad­di­tion to cal­cu­lat­ing tem­per­a­ture aver­ages for Europe, Cour­tillot and his col­leagues cal­cu­lated tem­per­a­ture aver­ages for the United States. Once again, their method yielded more re­fined aver­ages that were not a close match with the coarser CRU tem­per­a­ture aver­ages. The warmest pe­riod was in 1930, slightly above the tem­per­a­tures at the end of the 20th cen­tury. This was fol­lowed by 30 years of cool­ing, then an­other 30 years of warm­ing.

Cour­tillot’s cal­cu­la­tions show the im­por­tance of mak­ing cli­mate data freely avail­able to all sci­en­tists to cal­cu­late global av­er­age tem­per­a­ture ac­cord­ing to the best sci­ence. Phil Jones, in re­sponse to the email hack­ing, said that CRU’s global tem­per­a­ture se­ries show the same re­sults as “com­pletely in­de­pen­dent groups of sci­en­tists.” Yet CRU would not share its data with in­de­pen­dent sci­en­tists such as Cour­tillot and McIn­tyre, and Cour­tillot’s se­ries are clearly dif­fer­ent.

At the up­com­ing Copen­hagen con­fer­ence, gov­ern­ments are ex­pected to fail to agree to an am­bi­tious plan to cut green­house gas emis­sions. Here’s a more mod­est, if mun­dane goal for them: They should agree to share the data from their na­tional me­te­o­ro­log­i­cal ser­vices so that in­de­pen­dent sci­en­tists can cal­cu­late global cli­matic tem­per­a­ture and iden­tify the roles of car­bon diox­ide and the sun in chang­ing it.

Phil Green is a statis­ti­cian, pres­i­dent of Green­bridge Man­age­ment Inc. and au­thor of the up­com­ing book mis­Lead­ing In­di­ca­tors. Vin­cent Cour­tillot, dis­cussed above, was ed­u­cated at the Uni­ver­sity of Paris and Stan­ford Uni­ver­sity, is a Pro­fes­sor of Geo­physics at the Uni­ver­sity of Paris (DenisDider­ot) and a spe­cial­ist in pa­le­o­mag­netism. The au­thor of more than 150 pa­pers in sci­en­tific jour­nals, he was elected to the French Academy of Sciences in Novem­ber of 2003. Since 2002, he has presided the Sci­ence Coun­cil of the City of Paris.

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