Himalayan glaciers

**Andre** · Nov14-09, 10:54 AM

Well there is little doubt that somebody is going to claim that glacier growth is caused by global warming as it happened some 9000 years ago.

abstract here

**sylas** · Nov14-09, 06:57 PM

Originally Posted by Andre

Well there is little doubt that somebody is going to claim that glacier growth is caused by global warming as it happened some 9000 years ago.

abstract here

It's more than merely a claim. It's a well supported conclusion backed up with multiple lines of research and many research papers.

Is anyone seriously doubting that there can be major regional differences in response to globally changing temperatures? Either now or in the past? And given this, is there anyone actually disputing that some glaciers may be advancing in the present due to changes arising in the present global warming episode?

NONE of the sources cited in this thread -- including the discussion paper, or the papers on the western Himalaya by Fowler and Archer, and by Shroder's group -- is disputing the observation that there is a significant worldwide trend of retreat in glaciers. They are looking at exceptions to the trend. Inferences and hypothesis about dynamics will also differ between scientists. Research on these anomalous glaciers that are advancing is critically useful for understanding better the complexities of glacier dynamics and their interaction with climate.

The links Andre is giving are to a recent publication and to an associated news report which is relevant to this whole discussion.

Rupper, S. et al. (2009) Spatial patterns of Holocene glacier advance and retreat in Central Asia, Quat. Res. 72(3), Nov 2009, pp337-346.
Thaindian news, Aug 28 2009, Why Himalayan glaciers grew while Asia heated up 9,000 years ago.

Glaciers are in a continuous state of change, and respond to changes in climate in sometimes quite complicated ways. There can be time delays in response; there are responses to temperature and to precipitation, and sudden surges or moves as melt water lubricates the base of a glacier and changes how much friction there is for movement. The paper is mostly on changes 6000 years ago, with some comparison also to 9000 years ago. The reference of the newspaper story title is about a few anomalous glaciers in central Asia which did advance in the early Holocene when global temperatures were increasing and most glaciers were retreating.

.. Although there is evidence for large pre-LGM and LGM advances in the southern Himalayas and Tibet (eastern zone), evidence for a large early Holocene (∼9 ka) advance distinguishes it from the rest of Central Asia...
-- Rupper et al (2009) p338

In the modern era, there are all kinds of quite drastic changes going on. Scientists investigating changes in glaciers can benefit from studying also the changes that have occurred in the past. An extract from the news report explains this plainly:

The story of these seemingly anomalous glaciers underscores the important distinction between the terms “climate change” and “global warming.”

“Even when average temperatures are clearly rising regionally or globally, what happens in any given location depends on the exact dynamics of that place,” Rupper said.

The findings come from a framework Rupper developed as an alternative to the notion that glaciers form and melt in direct proportion to temperature.
-- Thaindian news Aug 28, 2009.

Global change and regional change

This paper is particularly relevant to the point which is being made in the previous references: that there are strong regional differences in a time of globally changing climate. The previous papers in this thread have explained and measured such differences. For example, from the abstract of Fowler and Archer (2006) (see msg #15):

The observed downward trend in summer temperature and runoff is consistent with the observed thickening and expansion of Karakoram glaciers, in contrast to widespread decay and retreat in the eastern Himalayas. This suggests that the western Himalayas are showing a different response to global warming than other parts of the globe.
-- Fowler et al (2006), abstract

The Earth periodically experiences times of strong global change, such as the start of the Holocene some 9000 years ago, or the current global warming trend. This research is helping to explore the changes at such times in more detail, and particularly to consider differences in different regions. To help it read more easily as a summary, I have removed the references. Here are the opening paragraphs of Rupper et al (2009):

In modern climate dynamics a central concept is that climate variability tends to be expressed in spatial patterns on a regional scale. Well-known examples of this are the El Nino-Southern Oscillation, the Pacific Decadal Oscillation, and the Arctic Oscillation. In past climates too, there are strong indications that climate changes occur in patterns, and no reason to suspect that they do not. Proper characterization and interpretation of past climate variability therefore requires a dense network of paleoclimate proxy records.

Glaciers are a particularly attractive paleoclimate proxy record for two reasons. First, geomorphic evidence of glacier advances is widespread across much of the Northern Hemisphere land masses. Second, glaciers are excellent recorders of properties of the atmosphere, retreating and advancing directly in response to changes in accumulation and ablation. Reconstructions of past glacier variability are some of the most useful records of paleoclimate. In fact, in many parts of the world, the glacier history is the primary descriptor of the climate history beyond the instrumental record, particularly where glacier deposits are widespread and confidently dated. This is true, for example, in the Pacific coast of the United States, South America, New Zealand, the European Alps, and Asia. Therefore, reconciling the glacier histories with the climatic variations that caused them is essential.

The glacier history of Central Asia provides a promising opportunity to distinguish between global and regional climate change. ...
-- Rupper et al (2009) p337

And from the conclusion:

The consistency between all GCMs reinforces confidence that the model results are a robust response of the climate to the changes in insolation forcing. In the case for Central Asia, spatial patterns in climate occur in response to a relatively uniform increase in solar insolation at the top of the atmosphere. The patterns in glacier advances across Central Asia are a result of the spatial variability in the climate response. This suggests that spatial patterns in climate and glaciers should be expected even in cases where there is a uniform change in forcing (e.g., increasing CO₂).
-- Rupper et al (2009) p345

Summer Rupper has also been in the news recently, for a letter to Utah legislators on policy responses to climate change issues.

"We have no specific political agenda to support but agree that whatever action is taken, it should be informed by the best available scientific evidence," the scientists said. "We encourage our legislators not to manipulate the scientific evidence to suit any political agenda."
[...]
Summer Rupper, a BYU climate scientist, led the letter-writing effort. ...
-- extract from BYU scientists take lawmakers to task on climate change issues, The Salt Lake Tribune, 7 July 2009

The letter that was sent is here: Open letter to the Utah Public Utilities and Technology Interim Committee, Governor, U.S. Senators and Congressmen.

Cheers -- sylas

**mheslep** · Nov15-09, 10:10 PM

On the subject of what is/is not controversial:

Originally Posted by sylas

Fowler, H. J. and Archer, D.R. (2006) Conflicting Signals of Climatic Change in the Upper Indus Basin, in Journal of Climate, Vol 19, Iss 17, Sept 2006, pp 4276-4293, doi:10.1175/JCLI3860.1. This paper also documents the western Himalaya as an exception to the overall trend of retreat.

I suspect part of the problem lies in the geographic hand waving in using the terms 'eastern', 'western', or 'Indian' Himalayas. I would say that it is not controversial that eastern Himalayan glaciers are retreating, nor is it controversial that western Himalayan glaciers are advancing. Yet here we have V.K. Raina’s report which after a quick scan proposes to report on 'Indian' glaciers , which I expect from glancing at the map includes some of both.

**Andre** · Dec6-09, 08:19 AM

An interesting devellopment

The UN panel on climate change warning that Himalayan glaciers could melt to a fifth of current levels by 2035 is wildly inaccurate, an academic says.

J Graham Cogley, a professor at Ontario Trent University, says he believes the UN authors got the date from an earlier report wrong by more than 300 years.

He is astonished they "misread 2350 as 2035". The authors deny the claims. ... cont'd

**Xnn** · Dec6-09, 05:09 PM

Can not find much of anything in the IPCC physical science basis concerning
the state of Himalayan glaciers.
No estimate given for current or historical surface area or volume.
Likewise, there are no projections given for the Himalayan glaciers.

http://www.ipcc.ch/pdf/assessment-re...1-chapter4.pdf

One would think that the Indians themselves would have a good idea
on the changes going on with the Himalayans glaciers. However, even
their very own report does not make an attempt to document the area
or volume of the Himalayan glaciers.

We have about 30 year of detailed area for artic sea ice. and yet nothing
comparable for the Himalayans.

**mheslep** · Dec6-09, 11:32 PM

The (incorrect?) 2035 Himilayan glacier decline statement is under AR4 Impacts, Adaptation and Vulnerability, Chap 10, Asia:

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).

http://www.ipcc.ch/pdf/assessment-re...-chapter10.pdf

**Xnn** · Dec7-09, 09:54 AM

It's not good that they are putting stuff in the Impact section
which can not be found in the Science bases section.

Anyhow, here are the complete paragraphs.

Himalayan glaciers cover about three million hectares or 17%
of the mountain area as compared to 2.2% in the Swiss Alps.
They form the largest body of ice outside the polar caps and are
the source of water for the innumerable rivers that flow across
the Indo-Gangetic plains. Himalayan glacial snowfields store
about 12,000 km3 of freshwater. About 15,000 Himalayan
glaciers form a unique reservoir which supports perennial rivers
such as the Indus, Ganga and Brahmaputra which, in turn, are
the lifeline of millions of people in South Asian countries
(Pakistan, Nepal, Bhutan, India and Bangladesh). The Gangetic
basin alone is home to 500 million people, about 10% of the
total human population in the region.

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).

The receding and thinning of Himalayan glaciers can be
attributed primarily to the global warming due to increase in
anthropogenic emission of greenhouse gases. The relatively high
population density near these glaciers and consequent
deforestation and land-use changes have also adversely affected
these glaciers. The 30.2 km long Gangotri glacier has been
receding alarmingly in recent years (Figure 10.6). Between 1842
and 1935, the glacier was receding at an average of 7.3 m every
year; the average rate of recession between 1985 and 2001 is
about 23 m per year (Hasnain, 2002). The current trends of
glacial melts suggest that the Ganga, Indus, Brahmaputra and
other rivers that criss-cross the northern Indian plain could likely
become seasonal rivers in the near future as a consequence of
climate change and could likely affect the economies in the
region. Some other glaciers in Asia – such as glaciers shorter
than 4 km length in the Tibetan Plateau – are projected to
disappear and the glaciated areas located in the headwaters of
the Changjiang River will likely decrease in area by more than
60% (Shen et al., 2002).

Table 10.9 lists 8 differant glaciers; how much they have receeded
and the average rate of recession over various time periods.
The rates vary between 5 to 135 m/year.

Anyhow, it's just surprising that the Indians themselves have not
made the effort to perform a comprehensive study. As glaciers
melt back at an accelerated rate, the meltoff will cause rivers
to flow at a greater rate during the melt season.
So, maybe they are all content with the enhanced river flow.

Eventually there will come a turning point when the flow will diminish.
However, specific projections need to be based on extensive and
comprehensive data and not just a hand full of points.

**mspelto** · Dec10-09, 08:33 AM

The Gangotri Glacier is an important glacier, as it runoff is used for hydropower in 2005 the Tehri Dam was finished on the Bhagirathi River, it is a 2400 mw facility that began producing hydropower in 2006. It is retreating significantly, but given a 30 km long glacier a retreat of even 20 m per year is not alarming. I was disappointed to see in Time magazine an incorrect note on the retreat of Khumbu Glacier, they noted 5 k. When in fact it is one kilometer. This level of retreat can be readily seen in recent satellite images and has been published by BAJRACHARYA and MOOL (2009). A look at Table 1 in this paper documents the retreat of a number of glaciers in the Everest region over the last 40+ years This level of retreat is similar to that of Zemu Glacier in Sikkim as well, this meltwater is also used for hydropower.