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Alarming facts on warming glaciers

Glaciers represent a natural competition between ice accumulation and ablation. Melting is the main cause of ablation of almost all glaciers. Indian Himalayan glaciers - there are more than 15,000 of them - are shrinking fast, and as they shrink, this part of the world is slowly losing one of its many attractions which reflect the grandeur of the mountains around them.

Glaciers in the Himalayas are fast retreating like other ice mountains the world over. A recent study showed that the last three decades of the 20th century have been the hottest period in 1,000 years. The melting of the Gangotri glacier is accelerating at an average retreat rate of 30 metres annually. The rate between 1935 and 1990 was 18 metres per year and 7 metres annually between 1842 and 1935.

It is also noted that Khumbu glacier from which Sir Edmund Hillary and Tenzing Norgay set out to conquer Mount Everest nearly 50 years ago has retreated 5 kms due to global warming. The overall deglaciation from 1962 to 2001 in the Baspa basin of Himachal Pradesh was 19%. Chhota Shigri of Chandra valley also withdrew about 12% in the last one and half decades. The deglaciation processes are also noticeable for large glaciers in Ganga headwater like Gangotri which shows about 10% decrease during the last 18 years. The maximum retreat of 34.5 metres per year have been observed at Meola glacier in Dhauliganga river basin. The retreat of the Parbati glacier is reported unusual and more alarming.

The main reason for deglaciation the world over is global warming. The atmospheric levels of the greenhouse gas carbon dioxide have increased since pre-industrial times from 280 part per million (ppm) to 360 ppm, a 31% increase. Carbon dioxide is a by-product of the burning of fossil fuels such as gasoline in an automobile or coal in a power plant generating electricity. Levels of atmospheric methane, another powerful greenhouse gas, have risen 145% in the last 100 years. Methane is derived from sources such as rice paddies, bacteria in bogs and fossil fuel production. Greenhouse gases such as nitrous oxide and carbon dioxide in the Earth's atmosphere decrease the escape of terrestrial thermal infrared radiation. Increasing carbon dioxide, therefore, effectively increases radiative energy input to the Earth.

But what happens to this radiative input is complex: it is redistributed by various physical processes. The positive radiative input tends to warm the surface, lower atmosphere. More of the outgoing terrestrial radiatives from the surface of the Earth is absorbed by the atmosphere and re-emitted at higher altitudes at lower temperature. This results in a positive radiative input that tends to warm the lower atmosphere and surface. This directly causes the retreat of glaciers.

Anthropogenic greenhouse gas emissions levels depend on the human population size, the level of economic activity, and the technologies in use. Increases in population and level of economic activity tend to be closely tied to increased use of energy. Insofar as fossil fuels are used as the source of this energy, increased use of energy will lead to increased carbon dioxide emissions unless sequestration, energy efficiency improvements, or other technologies can balance it.

In addition to this, aerosol, a long recognised major environmental hazard, is also now known to have strong impacts on South and East Asian climates. It has been estimated that aerosol may reduce by up to 10% of the seasonal mean solar radiation reaching the earth surface, producing a global cooling effect that opposes global warming.

This means that the potential perils that humans have committed to global warming may be far greater than what we can detect at present.

As a key component of the Earth's climate system, the water cycle is profoundly affected by the presence of aerosols in the atmosphere. Through the so-called "direct effect" aerosol scatters and/or absorbs solar radiation, thus cooling the earth surface and changing the horizontal and vertical heating contrast in the atmosphere. The heating contrast drives anomalous atmospheric circulation, resulting in changes in convection, clouds and rainfall.

Another way aerosol can affect the water cycle is through the so-called "indirect effects" whereby aerosol increases the number of cloud condensation nuclei, prolongs lifetime of clouds, and inhibits the growth of cloud-drops to raindrops. This leads to more clouds, and increased reflection of solar radiation, and further cooling on the Earth's surface.

In monsoon regions, the response of the water cycle to aerosol forcing is especially complex, not only because of the presence of a diverse mix of aerosol species with vastly different radiative properties, but also because the monsoon is strongly influenced by ocean and land surface processes, land use, land change as well as regional and global greenhouse warming effects.

Thus, sorting out the impacts of aerosol forcing and interaction with the monsoon water cycle is a very challenging problem. The direct impact of greenhouse gas emission and resultant global warming on the glacier environment is melting. There are different reasons for ice melting. Its repercussions are also different, depending on regional and climatic variables. Flood, sea level rise, fresh water scarcity, threat to fauna and flora are major security implications of deglaciation. With an estimated contribution of 0.2-0.4 mm per year from melting glaciers, the average global sea level rose by 1-2 mm per year during the 1900s.

It is expected that the melting ice from ice caps and glaciers will raise sea levels between 10 and 90 cms in the 21st century. It is observed that about 20,000 years ago, the sea level was 25 metres lower than it's today. Sea-level rise will affect coastal regions throughout the world, causing flooding, erosion, and saltwater intrusion into aquifers and freshwater habitats. Even the modest sea-level rise seen during the 20th century led to erosion and the loss of 100 sq km of wetlands per year in the US Mississippi river delta. In Trinidad and Tobago, as in many low-lying islands, beaches are retreating several metres per year and salinity levels have begun to rise in coastal aquifers. Small Pacific islands such as Tonga, the Marshall Islands and the federated states of Micronesia are particularly vulnerable, and could lose large portions of their land area to rising seas and storm surges. A global sea level rise of 1 metre would inundate 80% of the Maldives; displace 24 million people in Bangladesh, India As 16% of the world's ocean water is contributed by the glaciers of the Himalayas, any environmental threat leading to excess deglaciation is to be viewed with more alacrity. It is also observed that any ecological bad effect in the Himalayas will have wider impacts on the lives of millions of people living in South Asia. If the Himalayan glaciers that feed seven of the great rivers of Asia (the Ganga, Indus, Brahmaputra, Salween, Mekong, Yangtze and Huang Hu) and ensure a year-round water supply to two billion people, vanish, it will be catastrophic for the entire Asia. It will create fresh water shortage, wipe out glacier feeding rivers and for the time being it will create floods in the region.

At present the rivers have shown 3-4% surplus water due to a 10% increase in the melting of the glaciers of the western Himalayas, and a 30% increase in the eastern Himalayan glaciers. But, after 40 years, most of these glaciers will be wiped out and then South Asia will have water problems. In March 2002, UK's Department of International Development funded a project called Sagarmatha (Snow and Glacier Aspects of Water Resources Management in the Himalayas) to assess the impact of deglaciation on the seasonal and long term water resources in snow-fed Himalayan rivers. This study was vital for policy-makers and specially those working on interlinking of rivers, as the flows available in rivers are likely to change dramatically over the decades depending on the region. The study which reveals some major facts about the melting mountain majesties and warming glaciers, is an eye-opener.

In Upper Indus, the study sites show initial increases of 14% and 90% in mean flows over the next few decades which will be followed by decreasing flows by 30% and 90% of baseline in the subsequent decades in a 100-year scenario. For Ganges, the response of the river near the glacier in Uttarkashi is different from downstream Allahabad. At Uttarkashi, flows peak at between 20% and 33% baseline within the first few decades and then recede to 50% of baseline after 50 years.

Near the source of the Brahmaputra, there is a general decrease in decadal mean flows for all temperature scenarios as glaciers are few in the area and flows recede as the permanent snow cover reduces with increasing temperature. The catchments in the eastern Himalayas which benefit from high precipitation of the summer monsoon, are more vulnerable to impacts of deglaciation than those in the west where the monsoon is weaker.

In short, the deglaciation in the Himalayas is influenced by various factors, climatic, regional etc. However, the main underlying factor is ever increasing warming on the mountains, chiefly because of excess emission of greenhouse gases and Asian brown cloud. The ongoing ice melting is only the tip of the iceberg that will hit us in the near future.

Professor Syed Iqbal Hasnain
Prof. Hasnain is the Vice-Chancellor of the University of Calicut in Kerala

Millions face glacier catastrophe as warming hits Himalayas

Sunday November 20, 2005

Nawa Jigtar was working in the village of Ghat, in Nepal, when the sound of crashing sent him rushing out of his home. He emerged to see his herd of cattle being swept away by a wall of water. Jigtar and his fellow villagers were able to scramble to safety. They were lucky: 'If it had come at night, none of us would have survived.'

Ghat was destroyed when a lake, high in the Himalayas, burst its banks. Swollen with glacier meltwaters, its walls of rock and ice had suddenly disintegrated. Several million cubic metres of water crashed down the mountain. When Ghat was destroyed, in 1985, such incidents were rare - but not any more. Last week, scientists revealed that there has been a tenfold jump in such catastrophes in the past two decades, the result of global warming. Himalayan glacier lakes are filling up with more and more melted ice and 24 of them are now poised to burst their banks in Bhutan, with a similar number at risk in Nepal.

But that is just the beginning, a report in Nature said last week. Future disasters around the Himalayas will include 'floods, droughts, land erosion, biodiversity loss and changes in rainfall and the monsoon'. The roof of the world is changing, as can be seen by Nepal's Khumbu glacier, where Hillary and Tenzing began their 1953 Everest expedition. It has retreated three miles since their ascent. Almost 95 per cent of Himalayan glaciers are also shrinking - and that kind of ice loss has profound implications, not just for Nepal and Bhutan, but for surrounding nations, including China, India and Pakistan.

Eventually, the Himalayan glaciers will shrink so much their meltwaters will dry up, say scientists. Catastrophes like Ghat will die out. At the same time, rivers fed by these melted glaciers - such as the Indus, Yellow River and Mekong - will turn to trickles. Drinking and irrigation water will disappear. Hundreds of millions of people will be affected. 'There is a short-term danger of too much water coming out the Himalayas and a greater long-term danger of there not being enough,' said Dr Phil Porter, of the University of Hertfordshire. 'Either way, it is easy to pinpoint the cause: global warming.'

According to Nature, temperatures in the region have increased by more than 1C recently and are set to rise by a further 1.2C by 2050, and by 3C by the end of the century. This heating has already caused 24 of Bhutan's glacial lakes to reach 'potentially dangerous' status, according to government officials. Nepal is similarly affected. 'A glacier lake catastrophe happened once in a decade 50 years ago,' said UK geologist John Reynolds, whose company advises Nepal. 'Five years ago, they were happening every three years. By 2010, a glacial lake catastrophe will happen every year.'

An example of the impact is provided by Luggye Tsho, in Bhutan, which burst its banks in 1994, sweeping 10 million cubic metres of water down the mountain. It struck Panukha, 50 miles away, killing 21 people. Now a nearby lake, below the Thorthormi glacier, is in imminent danger of bursting. That could release 50 million cubic metres of water, a flood reaching to northern India 150 miles downstream.

'Mountains were once considered indomitable, unchanging and impregnable,' said Klaus Tipfer, of the United Nations Environment Programme. 'We are learning they are as vulnerable to environmental threats as oceans, grasslands and forest.' Not only villages are under threat: Nepal has built an array of hydro-electric plants and is now selling electricity to India and other countries. But these could be destroyed in coming years, warned Reynolds. 'A similar lake burst near Machu Picchu in Peru recently destroyed an entire hydro-electric plant. The same thing is waiting to happen in Nepal.'

Even worse, when Nepal's glaciers melt, there could be no water to drive the plants. 'The region faces losing its most dependable source of fresh water,' said Mike Hambrey, of the University of Wales. A Greenpeace report last month suggested that the region is already experiencing serious loss of vegetation. In the long term, starvation is a real threat.

'The man in the street in Britain still isn't sure about the dangers posed by global warming,' said Porter. 'But people living in the Himalayas know about it now. They are having to deal with its consequences every day.'

Source: The Guardian, London

Global Warming and the Media

by Nirmal Ghosh

December 20, 2005: WORLDWIDE marches urging US President George Bush and British Prime Minister Tony Blair to do more to support the Kyoto Protocol at the start of the just concluded Montreal talks, showed the public's growing awareness of environmental issues that have so far often been the domain of scientists, bureaucrats and paid lobbyists.

Recent climate-related disasters may have brought some sense of immediacy to the situation. That has been supported by a growing mountain of evidence that global warming is in fact taking place.

At an International Media and Environment Summit in Kuching in the first week of December - the first of its kind - Canada's celebrated science professor David Suzuki addressed some 300 delegates from environmental and wildlife non government organisations (NGOs), the private sector and the media and reminded them that the planet's best scientific brains have long warned that the health of the biosphere is in steep decline.

The conference at the edge of Asia's last remaining tropical rainforest, and near the sites of Kalimantan's forest fires that have presented ASEAN with a transboundary environmental disaster - was called to discuss the role of the media in informing the public of the facts.

Professor Suzuki recalled that in November 2002, 1,700 of the world's leading scientists, including the majority of Nobel laureates in the sciences, had warned in an open document that ''Human beings and the natural world are on a collision course.''

''Human activities inflict harsh and often irreversible damage on the environment and on critical resources. If not checked, many of our current practises put at serious risk the future that we wish for human society, and may so alter the living world that it will be unable to sustain life in the manner that we know'' the document said.

The scientists urged fundamental change, but their message was relegated to the inside pages of newspapers, and buried in the avalanche of information, debate, propaganda and misinformation of the politicised greenhouse gas reduction issue.

Since then there have been regular warnings by scientists and NGOs, not least over what many agree will very soon be a key issue over which countries may even go to war - shrinking fresh water supplies.

Hurricane Katrina showed what happens when the best scientific brains are ignored, professor Suzuki reminded the audience.

And the disaster brought home a fundamental truth about global warming - that it is a reality, and it affects people across the globe regardless of who they are and what they do. Global warming affects a Sherpa in Nepal as much as a musician in New Orleans and a stockbroker in London.

Many of the demonstrations across the world held to coincide with the conference of the parties to the Kyoto accord in Montreal were organised by activist groups.

But the numbers - 7,000 in Montreal and 10,000 in London - showed that concern has spilled over from sensitised sectors to the general population, which now demands information and action.

The Kyoto protocol sets legally binding targets for reducing greenhouse gas emissions from developed countries between 2008 and 2012.

President Bush has not signed it; Prime Minister Blair signed it but this year said England could not meet the targets because if it did, it would hurt the domestic economy.

At Montreal the parties met for the first time, to review the protocol's implementation. With the exception of the USA, they agreed to set new targets on greenhouse gas emissions when the treaty expires in 2012.

Whether the media has done enough to tell the real story on global warming and other environmental issues was hotly debated at Kuching. And the conclusion by and large was, it has not.

''Coverage of environmental issues in this region has increased over the last decade,'' ASEAN secretary general Ong Keng Yong said at Kuching.

''But it still remains fairly limited and largely reactive. Stories on the environment do not grab the public's attention the way political and economic stories do, unless the stories are controversial or negative - be it related to the politics surrounding the Kyoto Protocol or more recently, natural disasters.''

The reasons for this are many. Environmental journalism has been reduced to a special interest subtype when it should be seen as cutting across sectors.

Hence it is seen as a luxury, with ''soft'' environment stories often being run in weekend editions or on inside feature pages. Making a career out of environmental journalism is often an uphill job, and in many cases general-interest reporters are not trained to handle the often complex and technical details of environmental issues, are unable to translate the science, and are vulnerable to swallowing misinformation.

''Environment news has been unfairly cast as a niche area. Tree-hugger sterotypes have not helped spark the interest of the general population. This should be changed,'' recommended Mr Ong.

Media owners and editors often counter that the media must provide what the public wants - and the public wants news on celebrities and sensational events.

But the media also has a greater, more traditional role - that of informing the public of facts for the greater good. The media is supposed to be an agent of change.

Noted Kathmandu-based Kunda Dixit, environmental journalist and editor of Nepali Times: ''Sceptics (on climate change) have had their say; now it is time to tell the real story.''

BBC environmental journalist Alex Kirby said the media's efforts to include the views of sceptics - however marginal - in reports injected a ''spurious balance'' that misled readers and viewers.

In Nepal and across the Himalayas whose glaciers provide the water that sustains roughly over a billion people in seven countries, the real story is shrinking glaciers - just one of an array of scientific facts that show global warming is taking place.

The fact that there is still debate does not mean human society must wait for the ultimate proof - disasters on an unprecedented scale both slow and sudden - to act, professor Suzuki said at Kuching.

It will take decades to reverse global warming. In the relief of reaching agreement at Montreal UK shadow environment secretary Peter Ainsworth injected a note of reality when he said, ''It's better than nothing but it isn't much. We need a great deal more than talk if we are going to stop the descent towards rapid and irreversible climate change.''

Noted professor Suzuki at Kuching: ''The growth of the economy has become the definition of progress. The danger of this concept is everything is being done to keep it growing indefinitely.''

''But the resources of the biosphere - air, water and soil - are fixed. We are depriving future generations of what we took for granted.''