Tuesday, November 10, 2009

Himalayan glaciers and the virtue of reading beyond the headline

My number one pet peeve with the blogosphere is that too many bloggers post on a new report or paper without actually looking at the new report or paper. Bloggers regularly bash mainstream media for lazy reporting then often go ahead and base entire posts solely on newspaper stories. Hypocrisy aside, it is a real shame. Blogs should be an opportunity to examine and debate science and policy issues in more depth than is available in the mainstream media

Case in point, the excitement in the blogosphere (see Roger Pielke Jr) over a new report from the Indian government claiming there is "no evidence" for climate change shrinking Himalayan glaciers. It's worth looking at the actual report.

First, the report is part of a series that "is meant to serve as a basis for informed debate and discussion on critical issues related to the environment." In other words, it is not a scientific assessment conducted by the Indian Government. The report even has a disclaimer that the views contained in the report "are not necessarily endorsed" by the government.

Second, the report is about glaciology. It contains no analysis that could determine, one way or another, if human-induced climate change is contributing to glacier decline. In order to detect a climate change signal, you'd need to combine the glaciology data with climate data and most likely models capable of simulating the evolution of the climate with and without human influence.

Third, despite all this, the report does in fact state that glaciers in the Himalayas have been retreating over the past century.

Glaciers in the Himalayas (India) have been exhibiting a continuous secular retreat since the earliest recording began around the middle of the nineteenth century. Kumdan glaciers, of the Upper Shyok valley, have been the only exception for their periodic fluctuations.

There are plenty of charts and graphs to support the fact that glaciers have been retreating. The author's quibble appears to be over the "alarmist" portrayals of glacier decline in other forums. The first line of the conclusion:

Data that has been generated from the glacier studies, in the Himalayas, over the last 100 years or so, indicates that the glaciers, in the Himalayas, have been, by and large, shrinking and retreating continuously, barring a flip here and there, but the rate of retreat can not be considered as alarming / abnormal, especially in the last decade or so.

The report presents no definition of "alarming / abnormal" (say, in terms of % change) nor does it present data or any analysis to test the notion that the retreat is or is not alarming / abnormal. All we're really left with is that glaciers are retreating and the retreat may or may not be caused by climate change.

5 comments:

glacierchange said...

Good point about reading the report. If you do read the report Figure 6 shows the retreat of Indian glaciers, than Table 9 that of Sikkim Glaciers. The magnitude of retreat is significant and quite consistent. All measures of mass balance also indicate negative balances in this report. In other words the glaciers are shrinking, the author specifies this cannot be pinned on global warming, but offers no compelling climate-glacier relationship to show why not, or why the retreat has been so widespread. This is a nice display of raw data, but not as good a job an example of data analysis of glacier change in the Himalaya. http://glacierchange.wordpress.com/2009/07/02/zemu-glacier-sikkim-thinning-and-retreat/
The following paper serves as a much better example. Its focus is on just one glacier, and the point is not to generalize to all glaciers, but illustrates connecting climate to the glaciers
http://www.the-cryosphere-discuss.net/3/765/2009/tcd-3-765-2009.pdf

skanky said...

You have to distinguish between those who don't read, and those who read, but don't understand (and those who haven't read, but wouldn't understand it if they did).

iamyouasheisme said...

I have to wonder if you read Pielke's post at his blog. His remarks were restrained, measured, and not at all conclusive. Hardly an example of unrestrained enthusiasm on the basis of reading headlines. That's why I read his blog - he does his homework.

What is interesting about the reports, just on the fact of it, is the fracus between the IPCC and the report writers. The author claims that the IPCC approach ignores the specifics of the Himalayan system in favor of a broad-brush approach. The IPCC fires back, "arrogance!"

Hmmm...should be simple to get to the bottom of this. I guess I'll download that report.

Your comment that the report is only about glaciology is a bit puzzling. The advocates of global warming theories say the earth is warming, and they cast their net about for evidence to support this. If glaciers are NOT receding, that is prima facie evidence against their theory. (Doesn't prove anything, but they have to explain the apparent discrepancy.) On the other hand, if glaciers, some of them, anyway, ARE receding, that doesn't really prove their point as they like to claim, because there are so many reasons why glaciers' mass flucuates over time. And, of course, some glaciers are well known to be growing now anyway.

Simon D said...

Iam, the content may have been measured but it was also ill-informed. If he read the report, he would know i) that it did not actually examine a connection between climate and glacial mass balance, ii) that it found that glaciers have indeed been retreating in the Himalayas over the past century, iii) that the report does not necessarily reflect the opinion of the Indian gov't. That may have provided some insight into why the head of the IPCC appeared so irritated by the report.

Details aside, the point here is simple. If you're going to report on something, READ it. Otherwise your readers get misled.

Steve Bloom said...

RP Jr. is a real piece of work, but I suppose we already knew that.

Raina's name rang a bell, and sure enough a search turned up this blurb from Morano's list of "skeptical" scientists on the Inhofe blog:

'VK Raina, India's leading Glaciologist, questioned the assertion that global warming was melting glaciers in India. "Claims of global warming causing glacial melt in the Himalayas are based on wrong assumptions," Raina told the Hindustan Times on February 11, 2007. The paper continued, "Raina told the Hindustan Times that out of 9,575 glaciers in India, till date, research has been conducted only on about 50. Nearly 200 years data has shown that nothing abnormal has occurred in any of these glaciers. It is simple. The issue of glacial retreat is being sensationalized by a few individuals, the septuagenarian Raina claimed. Throwing a gauntlet to the alarmist, he said the issue should be debated threadbare before drawing a conclusion.'

The article seems to have aged out, but I think we get the idea. RP Jr. promoting this guy is just as bad as doing so with Bill Gray. Oh, wait...