IPCC erkent fout, maar imagoherstel is nog ver weg

Het zal lezers van deze blog vermoedelijk niet ontgaan zijn dat het IPCC gisteren officieel heeft erkend dat het in de fout is gegaan bij wat we nu maar even voor het gemak Himalaya-gate zullen dopen. Bij mijn weten is het een unicum dat het IPCC openlijk een fout erkent, dat is dus een pluspunt (ik houd me aanbevolen voor andere voorbeelden), maar de manier waarop verdient verre van de schoonheidsprijs.

Eerst de verklaring:

IPCC Secretariat

Geneva, 20 January 2010

IPCC statement on the melting of Himalayan glaciers1

The Synthesis Report, the concluding document of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (page 49) stated: “Climate change is expected to exacerbate current stresses on water resources from population growth and economic and land-use change, including urbanisation. On a regional scale, mountain snow pack, glaciers and small ice caps play a crucial role in freshwater availability. Widespread mass losses from glaciers and reductions in snow cover over recent decades are projected to accelerate throughout the 21st century, reducing water availability, hydropower potential, and changing seasonality of flows in regions supplied by meltwater from major mountain ranges (e.g. Hindu-Kush, Himalaya, Andes), where more than one-sixth of the world population currently lives.”

This conclusion is robust, appropriate, and entirely consistent with the underlying science and the broader IPCC assessment.

It has, however, recently come to our attention that a paragraph in the 938 page Working Group II contribution to the underlying assessment2 refers to poorly substantiated estimates of rate of recession and date for the disappearance of Himalayan glaciers. In drafting the paragraph in question, the clear and well-established standards of evidence, required by the IPCC procedures, were not applied properly.

The Chair, Vice-Chairs, and Co-chairs of the IPCC regret the poor application of well-established IPCC procedures in this instance. This episode demonstrates that the quality of the assessment depends on absolute adherence to the IPCC standards, including thorough review of “the quality and validity of each source before incorporating results from the source into an IPCC Report” 3. We reaffirm our strong commitment to ensuring this level of performance.

1 This statement is from the Chair and Vice-Chairs of the IPCC, and the Co-Chairs of the IPCC Working Groups.
2 The text in question is the second paragraph in section 10.6.2 of the Working Group II contribution and a repeat of part of the paragraph in Box TS.6. of the Working Group II Technical Summary of the IPCC Fourth Assessment Report.
3 This is verbatim text from Annex 2 of Appendix A to the Principles Governing IPCC Work.

2035 schittert door afwezigheid
Twee zaken vallen op. IPCC begint met op te merken dat gletsjers deze eeuw over de hele wereld versneld zullen gaan afsmelten. Die conclusie is volgens IPCC ‘robuust’. Daarna geeft het IPCC toe dat hun strikte procedures [lees: gebruik maken van peer-reviewed literature en die literatuur ook goed checken] niet goed zijn uitgevoerd waardoor schattingen van de afname van gletsjers in de Himalaya ‘zwak onderbouwd’ zijn. Het jaartal ‘2035’ waar de hele rel om draait, schittert door afwezigheid.

De volgorde in de statement had andersom moeten zijn. IPCC had eerst de fout moeten erkennen en daarbij de passage uit het IPCC-rapport integraal moeten tonen:

“Glaciers in the Himalaya are receding faster than in any other part of the world (see Table 10.9) and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps warming at the current rate. Its total area will likely shrink from the present 500,000 to 100,000 km2 by the year 2035 (WWF, 2005).” (IPCC AR4 WG2 Ch10, p. 493)

Niet een maar vijf fouten
Het had vervolgens duidelijk moeten maken dat er geen wetenschappelijke basis is voor het jaartal 2035 en het had ook veel explicieter duidelijk moeten maken waar dat getal dan wel vandaan kwam. Integraal tonen van de passage had ook moeten leiden tot het erkennen van nog een paar fouten. Want gisteren kwam persdienst AP met een stuk dat stelde dat er niet één maar vijf fouten in de alinea (plus een tabel) over de Himalaya-gletsjers zitten:

“It is a very shoddily written section,” said Graham Cogley, a professor of geography and glaciers at Trent University in Peterborough, Canada, who brought the error to everyone’s attention. “It wasn’t copy-edited properly.”

Cogley, who wrote a letter about the problems to Science magazine that was published online Wednesday, cited these mistakes:

– The paragraph starts, “Glaciers in the Himalayas are receding faster than in any other part of the world.” Cogley and Michael Zemp of the World Glacier Monitoring System said Himalayan glaciers are melting at about the same rate as other glaciers.

– It says that if the Earth continues to warm, the “likelihood of them disappearing by the 2035 and perhaps sooner is very high.” Nowhere in peer-reviewed science literature is 2035 mentioned. However, there is a study from Russia that says glaciers could come close to disappearing by 2350. Probably the numbers in the date were transposed, Cogley said.

– The paragraph says: “Its total area will likely shrink from the present 500,000 to 100,000 square kilometers by the year 2035.” Cogley said there are only 33,000 square kilometers of glaciers in the Himalayas.

– The entire paragraph is attributed to the World Wildlife Fund, when only one sentence came from the WWF, Cogley said. And further, the IPCC likes to brag that it is based on peer-reviewed science, not advocacy group reports. Cogley said the WWF cited the popular science press as its source.

– A table says that between 1845 and 1965, the Pindari Glacier shrank by 2,840 meters. Then comes a math mistake: It says that’s a rate of 135.2 meters a year, when it really is only 23.5 meters a year.

Robuust
De statement is nu zodanig vaag opgesteld dat het IPCC zelf en aanhangers ervan al snel weer zullen roepen: ‘He, we hebben de fout erkend, maar het verandert niks aan wat we weten over de opwarming van de aarde in het algemeen en de gletsjers in de Himalaya in het bijzonder.’ Immers het statement zegt ‘Widespread mass losses from glaciers and reductions in snow cover over recent decades are projected to accelerate throughout the 21st century.’

Laten we eens teruggaan naar het Indiase rapport dat in november werd gepubliceerd. Een van de conclusies luidde:

It is premature to make a statement that glaciers in the Himalayas are retreating abnormally because of the global warming. A glacier is affected by a range of physical features and a complex interplay of climatic factors. It is therefore unlikely that the snout movement of any glacier can be claimed to be a result of periodic climate variation until many centuries of observations become available. While glacier movements are primarily due to climate and snowfall, snout movements appear to be peculiar to each particular glacier.

Voodoo science
Dit conflicteert sterk met de claim die IPCC ons nu opnieuw probeert in te wrijven: ‘Widespread mass losses from glaciers and reductions in snow cover over recent decades are projected to accelerate throughout the 21st century.’ Hoe reageerde IPCC ook alweer op het Indiase overheidsrapport? Pachauri noemde India ‘arrogant‘ en het rapport kwalificeerde hij als voodoo science.

De betiteling ‘arrogant’ stond in The Guardian:

India ‘arrogant’ to deny global warming link to melting glaciers
IPCC chairman Rajendra Pachauri accuses Indian environment ministry of ‘arrogance’ for its report claiming there is no evidence that climate change has shrunk Himalayan glaciers.
(…) However, Rajendra Pachauri, the chairman of the IPCC, told the Guardian: “We have a very clear idea of what is happening. I don’t know why the minister is supporting this unsubstantiated research. It is an extremely arrogant statement.”
Vijay Kumar Raina, the geologist who authored the report, admitted that some “Himalayan glaciers are retreating. But it is nothing out of the ordinary. Nothing to suggest as some have said that they will disappear.”
Pachauri dismissed the report saying it was not “peer reviewed” and had few “scientific citations”.
“With the greatest of respect this guy retired years ago and I find it totally baffling that he comes out and throws out everything that has been established years ago.”

De ironie is uiteraard groot dat twee maanden later Pachauri moet erkennen dat op het punt van de gletsjers in de Himalaya juist het IPCC-rapport gebruikt maakte van ‘unsubstantiated research’ en ook dat de gebruikte informatie niet ‘peer reviewed’ was en er dus helemaal geen sprake was van ‘scientific citations’. Het had Pachauri dan ook gesierd als hij zijn verontschuldigingen had aangeboden aan zowel Raina (de geoloog die het rapport schreef) als aan de Indiase minister Ramesh, in wiens opdracht het rapport tot stand was gekomen. Met een veel duidelijker officieel statement en een duidelijke terugtrekking van het jaartal 2035 aangevuld met een persoonlijke verontschuldiging van Pachauri hadden IPCC en Pachauri de boel wellicht wat kunnen sussen.

Geen teken van afsmelting
Het prestigieuze Science besteedde in november overigens vrij uitgebreid aandacht aan de het Indiase rapport en was lang niet zo negatief als Pachauri. De titel zegt al veel: No Sign Yet of Himalayan Meltdown, Indian Report Finds. Pachauri’s rechterhand in deze kwestie, Syed Hasnain (op wie ik nog terugkom), was negatief:

Some glaciologists hew to IPCC’s view, disputing Raina’s conclusions. Any suggestion that the retreat of Himalayan glaciers has slowed is “unscientific,” charges Syed Iqbal Hasnain, a senior fellow at the Energy and Resources Institute in New Delhi. He says the Indian government has an “ostrichlike attitude in the face of impending apocalypse.”

Maar andere (westerse) onderzoekers delen de mening van Raina:

Several Western experts who have conducted studies in the region agree with Raina’s nuanced analysis—even if it clashes with IPCC’s take on the Himalayas. The “extremely provocative” findings “are consistent with what I have learned independently,” says Jeffrey S. Kargel, a glaciologist at the University of Arizona, Tucson. Many glaciers in the Karakoram Mountains, which straddle India and Pakistan, have “stabilized or undergone an aggressive advance,” he says…

Kenneth Hewitt, a glaciologist at Wilfrid Laurier University in Waterloo, Canada, who just returned from an expedition to mountain K2, says he observed five glacier advances and a single retreat in the Karakoram. Such evidence “challenges the view that the upper Indus glaciers are ‘disappearing’ quickly and will be gone in 30 years,” Hewitt says. “There is no evidence to support this view and, indeed, rates of retreat have been less in the past 30 years than the previous 60 years,” he says.

Deze laatste opmerking van Hewitt ondergraaft de bewering in het IPCC-statement van gisteren dat ‘Widespread mass losses from glaciers and reductions in snow cover over recent decades are projected to accelerate throughout the 21st century.’ Het is dan ook sterk de vraag hoe ‘robuust’ de conclusies van het IPCC op dit gebied zijn. Het wachten is eerder op meer en meer IPCC-conclusies die bij nader inzien slecht onderbouwd zijn.