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Are the glaciers in Tibet melting?

Posted on: June 17, 2010

 

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It is reported that global warming is melting the glaciers in the Tibetan plateau and that this process will cause 1/3 of these glaciers to disappear in 10 years (Global warming spells doom for Asia’s rivers, Bangkok Post, June 16, 2010). The article claims that declining water flow in the Yellow and Yangtze rivers, and in particular, the severe decline in Mekong waters in Southeast Asia downstream of China, are due to the loss of glacial mass caused by global warming and that these changes have doomed 1.3 billion people in Asia to death by global warming. No explanation is offered for why an increase in the melt rate of source glaciers decreases water flow in the rivers they feed instead of increasing it.

This story first surfaced in mid 2004 with a warning of “ecological catastrophe” from Tibet’s glaciers that have been melting for the last 40 years as a consequence of climate change and that would continue to melt at a rate of 7% per year and reduce water flow in the rivers fed by the glaciers. As to why an increase in the melt rate does not increase the flow rate in the rivers, it was proposed that global warming was again to blame because it was causing all that excess melt water to evaporate.

All of these conclusions were derived from the discovery of a number of ice islands that were assumed to have separated from their glaciers. It was predicted that without human intervention in the form of emission reductions 64% of the Tibetan glaciers would be gone by the year 2050 and all of it would vanish by the year 2100. The year 2100 plays a magical role in global warming theory as some kind of end time when the full wrath of every aspect of climate change doom will be realized.

Later the same year in 2004, a different story was floated. It said that a visit to the Zepu glacier in Tibet at an elevation of 11,500 feet showed a torrent of melt water gushing out at an alarming rate and all that excess water was forming the headwaters of a river downstream at a much higher elevation due to global warming. Their data showed that 30 years prior to that date, Zepu was 100 yards thicker. They concluded that what is happening to Zepu is happening to all the glaciers in Tibet and what is happening in Tibet is happening globally. Glaciers are melting all over the world due to global warming with the possible exception of Scandinavia.

The story changed again in 2006 when it was announced with a great sense of alarm that global warming was causing sandstorms in Beijing by way of melting glaciers and drought. This version of the story came in the aftermath of the unusually large sandstorm event in Beijing in April 2006 that captivated TV audiences and made headlines around the world; but the effort to sell global warming on the back of this tragedy was ineffective as the expansion of the Gobi desert is historical and a well understood phenomenon linked to over-grazing and other land use issues and not due to melting glaciers.

However, the story that the Tibetan glaciers were melting and threatening water supplies to a billion people continued to re-appear in 2007 and 2008 but went on a hiatus in 2009 when excessive amounts of black soot deposits were found in core samples of Tibetan glaciers implying that accelerated melting if any was more likely due to soot than to global warming.

Yet another deterrent to hyping global warming with Tibetan glaciers came in early 2010 when it was found that the Tibetan glaciers were unique in that they never got very big but varied in size within a range that was not very large with their temperature sensitivity not very significant even going as far back as the last ice age.

Also of note is that there is no evidence that water flow in the Yellow, the Yangtze, or the Mekong is declining in the river as a whole. The only evidence presented is that water flow in the Mekong in Laos and Thailand – downstream of China – has declined. In fact it has, but that could not have been caused by a decline in the flow of its headwaters for that would have affected flow in the entire length of the river and not just in a section thousands of miles downstream.

The loss of water in the lower Mekong has received a lot of attention in Southeast Asia and it has been a contentious water sharing issue with China which has built a number of dams upstream but it is not a glacial headwaters issue, nor a global warming issue. No one here would take it seriously that the water problem in the Southeast Asian section of the Mekong would be alleviated by lowering carbon dioxide emissions.

Consider also that the Mekong is fed mostly by monsoon rains with a water flow that is highly seasonal. Its flow during the monsoon is 30 times its flow during the dry season. Therefore if there were a climate related decrease in the total amount of water it carries it would have to do with the monsoons and not with glaciers. Coincidentally, climate scientists had made the same error in 2007 when they had said that the Ganges river – which receives less than 10% of its water from glacial melt – would dry up because of melting glaciers.

So it is curious to find them attempting to revive the Tibetan glacier story yet again in the light of these data and in the heels of their humiliating retraction of similar false alarms about Himalayan glaciers. It is likely that real evidence of global warming catastrophe is hard to come by these days and there is a certain degree of desperation in the global warming camp to keep the issue alive in the media.

 

 

 

BIBLIOGRAPHY

  1. Bajracharya, Samjwal Ratna, Pradeep Kumar Mool, and Basanta Raj Shrestha. “Global climate change and melting of Himalayan glaciers.” Melting glaciers and rising sea levels: Impacts and implications (2008): 28-46. Since industrialization, human activities have significantly altered the atmospheric composition, leading to climate change of an unprecedented character. The global mean temperature is expected to increase between 1.4 to 5.8ºC over the next hundred years. The consequences of this change in global climate are already being witnessed in the Himalayan glaciers and glacial lakes. The Himalayan glaciers are retreating at rates ranging from 10 to 60 metres per year and many small glaciers (<0.2 sq km) have already disappeared. Vertical shift of glaciers as great as 100m have been recorded during the last fifty years. With the result of retreating glaciers, the lakes are growing in number and size as well in the Himalaya. A remarkable example is Lake Imja Tsho in the Everest region; while this lake was virtually nonexistent in 1960, now it covers nearly 1 sq km in area. Similar observations were made in the Pho Chu basin of the Bhutan Himalaya, where the change in size of some glacial lakes has been as high as 800 per cent over the past 40 years. At present, several supraglacial ponds on the Thorthormi glacier are growing rapidly and consequently merging to form a larger lake. These lakes pose a threat of glacial lake outburst flood (GLOF), and GLOFs are often catastrophic on life and property of the mountain people living downstream. At least thirty-two GLOF events recorded in Himalaya that resulted in heavy loss of human lives and their property,
    destruction of infrastructure besides damages to agriculture land and forests. The global warming in the coming decades will amplify the GLOF events with the accelerating retreat of glaciers and formation of many potentially dangerous glacial lakes. Monitoring of glaciers and glacial lakes are utmost important to understand the status of the lake and need to prioritized for the installation of early warning systems and mitigation measures before planning the mountain infrastructure for the sustainable development. Regional cooperation is also required for knowledge management on GLOF issues due to trans-boundary nature of GLOF phenomena.
  2. Raina, Vijay Kumar. “Himalayan glaciers: a state-of-art review of glacial studies, glacial retreat and climate change.” Himalayan glaciers: a state-of-art review of glacial studies, glacial retreat and climate change. (2009).   The aim of this series is to encourage informed science-based discussion and debate on critical environmental issues. Each of these papers will provide an expert perspective, backed by rigorous evidence, on important issues related to the environment. In some ways, a paper on the Himalayan Glaciers is a befitting way to launch this working paper series, as it is an issue on which there is considerable academic and popular limelight, with a number of varying points of view. Study of the phenomenon of glaciation and glacier dynamics in the Himalayas has, in recent years, attained significant attention, on account of the general belief that global warming and climate change is leading to fast degeneration of glaciers in the Himalayas. It is argued that this would, in the long run, not only have an adverse effect on the environment, climate and the water resources but also on other concerned and connected activities. This paper provides a summary of the literature, as well as some fresh analysis of the issue. An interesting point made in this paper is that while glaciers are the best barometers known to assess past climate, the same may not be true for glacier fluctuations being an accurate guide of future climatic changes.
  3. Immerzeel, Walter W., Ludovicus PH Van Beek, and Marc FP Bierkens. “Climate change will affect the Asian water towers.” Science 328.5984 (2010): 1382-1385.  More than 1.4 billion people depend on water from the Indus, Ganges, Brahmaputra, Yangtze, and Yellow rivers. Upstream snow and ice reserves of these basins, important in sustaining seasonal water availability, are likely to be affected substantially by climate change, but to what extent is yet unclear. Here, we show that meltwater is extremely important in the Indus basin and important for the Brahmaputra basin, but plays only a modest role for the Ganges, Yangtze, and Yellow rivers. A huge difference also exists between basins in the extent to which climate change is predicted to affect water availability and food security. The Brahmaputra and Indus basins are most susceptible to reductions of flow, threatening the food security of an estimated 60 million people.
  4. Scherler, Dirk, Bodo Bookhagen, and Manfred R. Strecker. “Spatially variable response of Himalayan glaciers to climate change affected by debris cover.” Nature geoscience 4.3 (2011): 156Controversy about the current state and future evolution of Himalayan glaciers has been stirred up by erroneous statements in the fourth report by the Intergovernmental Panel on Climate Change1,2. Variable retreat rates3,4,5,6 and a paucity of glacial mass-balance data7,8 make it difficult to develop a coherent picture of regional climate-change impacts in the region. Here, we report remotely-sensed frontal changes and surface velocities from glaciers in the greater Himalaya between 2000 and 2008 that provide evidence for strong spatial variations in glacier behaviour which are linked to topography and climate. 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. 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. In contrast, more than 50% of observed glaciers in the westerlies-influenced Karakoram region in the northwestern Himalaya are advancing or stable. 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 availability9,10 or global sea level11.
  5. Shrestha, Arun B., and Raju Aryal. “Climate change in Nepal and its impact on Himalayan glaciers.” Regional Environmental Change 11.1 (2011): 65-77.  Climate change can be particularly hard-hitting for small underdeveloped countries, relying heavily on natural resources for the economy and livelihoods. Nepal is one among these countries, being landlocked, with diverse physiographical characteristics within a relatively small territory and with rugged terrain. Poverty is widespread and the capacity of people and the country to cope with climate change impact is low. The country is dominated by the Asian monsoon system. The main occupation is agriculture, largely based on rain-fed farming practices. Tourism based on high altitude adventures is one of the major sources of income for the country. Nepal has a large hydropower potential. While only 0.75% of the theoretical hydropower potential has been tapped, Nepal can greatly benefit from this natural resource in the future. Climate change can adversely impact upon water resources and other sectors of Nepal. The source of water is mainly summer monsoon precipitation and the melting of the large reserve of snow and glaciers in the Himalayan highlands. Observations show clear evidences of significant warming. The average trend in the country is 0.06°C per year. The warming rates are progressively higher for high elevation locations. The warming climate has resulted in rapid shrinking of majority of glaciers in Nepal. This paper presents state-of-knowledge on the glacial dynamics in the country based on studies conducted in the past in Shorong, Khumbu, Langtang, Dhaulagiri and Kanchenjunga regions of Nepal. We present recent trends in river flow and an overview of studies on expected changes in the hydrological regime due to climate change. Formation, growth and likely outburst of glacial lake are phenomena directly related to climate change and deglaciation. This paper provides a synopsis of past glacial lake outburst floods impacting Nepal. Further, likely impacts of climate change on other sectors such as agriculture, biodiversity, human health and livelihoods are discussed.
  6. Bolch, Tobias, et al. The state and fate of Himalayan glaciers. Science 336.6079 (2012): 310-314.  Himalayan glaciers are a focus of public and scientific debate. Prevailing uncertainties are of major concern because some projections of their future have serious implications for water resources. Most Himalayan glaciers are losing mass at rates similar to glaciers elsewhere, except for emerging indications of stability or mass gain in the Karakoram. A poor understanding of the processes affecting them, combined with the diversity of climatic conditions and the extremes of topographical relief within the region, makes projections speculative. Nevertheless, it is unlikely that dramatic changes in total runoff will occur soon, although continuing shrinkage outside the Karakoram will increase the seasonality of runoff, affect irrigation and hydropower, and alter hazards.

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