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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Himalayan glaciers: how the IPCC erred and what the science says

What the science says...

Select a level... Basic Intermediate

Glaciers are in rapid retreat worldwide, despite 1 error in 1 paragraph in a 3000 page IPCC report.

Climate Myth...

IPCC were wrong about Himalayan glaciers


"In 1999 New Scientist reported a comment by the leading Indian glaciologist Syed Hasnain, who said in an email interview with this author that all the glaciers in the central and eastern Himalayas could disappear by 2035.


Hasnain, of Jawaharlal Nehru University in Delhi, who was then chairman of the International Commission on Snow and Ice's working group on Himalayan glaciology, has never repeated the prediction in a peer-reviewed journal. He now says the comment was "speculative".


Despite the 10-year-old New Scientist report being the only source, the claim found its way into the IPCC fourth assessment report published in 2007. Moreover the claim was extrapolated to include all glaciers in the Himalayas." (Fred Pearce)


The IPCC made an error about the Himalayan glaciers. Section 10.6.2 of the Fourth Assessment Report (AR4) states, “the likelihood of [the Himalayan Glaciers] disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps warming at the current rate.” This statement did not come from peer-reviewed literature, nor did it meet the IPCC standards of evidence.

The error has raised some criticisms - both legitimate and illegitimate - about the the IPCC, the AR4, and climate science in general:

Did the IPCC respond to this error quickly and diligently? The answer here is unfortunately no. According to a review by the InterAcademy Council on the IPCC processes and procedures, the IPCC took more than a month to respond to the Himalayan Glacier error, and even then did not explicitly acknowledge the error or issue a retraction. To make matters worse, it has been documented that the IPCC had responded more quickly to other supposed errors in the report (Leake, 2010; Reuters, 2010). Though the IPCC has been recognized for its scientific contributions, there is certainly room for improvement in terms of communications.

Is the AR4 terribly flawed? It is important to note that this is one error in a roughly 3000 page technical document, an error percentage similar to the Encyclopedia Britannica. The 2035 claim was not included in the Technical Summary, the Summary for Policymakers, or the Synthesis Report.

Does this error show the IPCC has an ‘alarmist’ bias – a tendency to exaggerate the negative impacts of climate change? In fact, there are far more documented instances of the AR4 being too conservative, rather than too alarmist, on emissions scenarios, sea level rise, and Arctic sea-ice melt.

Does this in anyway undermine climate science in general? To claim this error undermines the basic conclusions of climate change is absurd. The error is part of Working Group II: Impacts, Adaptation and Vulnerability, not Working Group I: The Physical Science Basis. Anthropogenic climate change is still supported by multiple lines of independent empirical evidence, and nearly every national and international scientific body.

So what does the peer-reviewed science say about the Himalayan Glaciers?

Many of the Himalayan Glaciers are retreating at an accelerating rate (Ren et al. 2006) and roughly 500 million people depend on the melt water from these glaciers (Kehrwald et al. 2008).

The IPCC made an unfortunate error in a very long technical document. Moreover, the response to this error was far from exemplary. Highlighting this error to undermine climate science, however, is a classic example of cherry picking – a dangerous game to play with 500 million livelihoods at stake.

Last updated on 17 September 2010 by Nicholas Berini. View Archives

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Further reading

IPCC statement on the melting of Himalayan glaciers

A comprehensive review of the whole incident is presented in the Yale Forum's Anatomy of IPCC’s Mistake on Himalayan Glaciers and Year 2035


Comments 1 to 11:

  1. I am afraid both the current versions of "Basic" and "Intermediate" need some revision. I think that the issue of the Himalayas proper and the issue of the central Asian highlands including the Himalayas should be distinguished. I have made some comments on the blog article of "Himalayan Glaciers, Wrong Date, Right Message. I am tempted to write clarification myself, but, regrettably, I cannot promise it. At least, Kehrwald et al. (2008) should not be used as a reference for the issue of population who depend on glaciers. Kehrwald et al. just quoted from IPCC AR4 WG2 (including the errorneous "prediction") and Barnett et al. (2005) about that. Kehrwald's paper seems to be a good reference about the mass balance of certain glaciers they studied. Also, the word "IPPC" in the title should be "IPCC".
  2. I'm glad to see, at least in the Intermediate version, that WG1 and WG2 are differentiated. There exist those that would invalidate all of WG1 on the basis of, effectively, a typo in WG2. The Yooper
  3. This says they are not retreating because of climate-change.
  4. From the Telegraph report : Their report, published in the journal Nature Geoscience, found the key factor affecting their advance or retreat is the amount of debris – rocks and mud – strewn on their surface, not the general nature of climate change. Glaciers surrounded by high mountains and covered with more than two centimetres of debris are protected from melting. Debris-covered glaciers are common in the rugged central Himalaya, but they are almost absent in subdued landscapes on the Tibetan Plateau, where retreat rates are higher. From the report itself : More than 65% of the monsoon-influenced glaciers that we observed are retreating, but heavily debris-covered glaciers with stagnant low-gradient terminus regions typically have stable fronts. Our study shows that there is no uniform response of Himalayan glaciers to climate change and highlights the importance of debris cover for understanding glacier retreat, an effect that has so far been neglected in predictions of future water availability,or global sea level. Interesting contribution which provides more detail. Hardly "they are not retreating because of climate-change" !
  5. Its black carbon deposited by pollution that plays the major role in the melting. The article does imply that the greenhouse effect does play a role but the majority of the melting is caused by black carbon deposits.

    [DB] Apart from Sphaerica's fine response, you may wish to read up a bit on Himalayan Glaciers.  Your NASA reference dates from 2009.  Glaciologist Mauri Pelto has a list of blog posts on glaciers worldwide here.  The Himalayan posts are all 2009-2011.  Mauri indicates that fresh snowfall on the glaciers tends to blunt the impacts of black soot on the glaciers (due to their altitude, they retain much of the fresh snow year-round in their accumulation zones).

    Despite this, many such as the Gangotri Glacier have receded heavily over the past century:


  6. 5, Roh234, Wrong. From the article you linked (emphasis mine):
    "Tibet's glaciers are retreating at an alarming rate," said James Hansen, coauthor of the study and director of NASA’s Goddard Institute for Space Studies (GISS) in New York City. "Black soot is probably responsible for as much as half of the glacial melt, and greenhouse gases are responsible for the rest."
    That says black soot gets up to but not more than half. This does not equal "the major role" and may in fact be at best equal to (but probably secondary to) greenhouse gases. The concluding line?
    "Reduced black soot emissions, in addition to reduced greenhouse gases, may be required to avoid demise of Himalayan glaciers and retain the benefits of glaciers for seasonal fresh water supplies," Hansen said.
    Which means the problem is even worse, because we now have two problems to fix instead of only one.
  7. Of course, black carbon and CO2 are often from same source. You might also note that black carbon has much lesser role on other ice melts (distance from asia). Also note that effect of black carbon is short-lived while CO2 is very much longer.
  8. You might also like to look at its soot if you are interested in the science rather than repeating skeptic talking points.
  9. Yeah, I always love the 'no it is soot' argument.... even if it were true, the solution would be exactly the same: transition away from the coal power plants which are the primary source of increasing atmospheric CO2 AND soot. Somehow 'skeptics' never seem to make that connection.
  10. @9, isn't the point that 'soot' can be scrubbed whereas CO2 cannot be scrubbed!??!

  11. Just wanting to point out the link under "Many of the Himalayan Glaciers are retreating" in the 2nd from last paragraph no longer goes anywhere.

    I'm not sure if this was due to a recent webpage change at USGS.

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