Climate change (CC), especially climate change caused by human action, raises much heat and sparks almost religious levels of contentiousness. Policy based on CC findings will drive huge resource allocations over the next several decades, quite apart from the minor detail that the planet we live on could become a far less hospitable place, given wrong policies.
There is also a north-south divide on going green. Rich nations want stringent controls on carbon emissions from fossil fuels. Poorer nations say this impedes poverty-reduction efforts by denying technology that is cheaper, if more polluting. This stalemate makes concerted global action difficult.
Models spanning centuries in scope have been released by activists and respected scientists. The science underlying CC models draws on many disciplines, making it ambiguous and difficult to peer-review, let alone to interpret for laypeople. CC models have large inbuilt error factors. Given vested interests, all interpretations tend to be considered suspect!
Sceptics have often queried methodology and assumptions and sometimes pointed out direct errors and omissions. It’s difficult to judge how much CC is natural, and how much, human-induced. The earth has seen vast Ice Ages when ice cover occupied thrice the current area. There have been very cold and very warm centuries in recorded history, long before technology made any impact.
One trigger point is Himalayan glaciers — the 32,292 mapped rivers of ice running through the world’s highest mountains. About 75 per cent of global fresh water resources are locked away as snow and ice. So, implications of changes in glaciation are huge. In the sub-continent itself, glacial melt could affect rainfall patterns, cause floods in the plains and flash floods in the hills, and interfere with hydroelectric projects.
India is taking it seriously. The National Action Plan on Climate Change (NAPCC) includes a National Mission for Sustaining the Himalayan ecosystem. A new research centre, the Wadia Institute of Himalayan Geology, in Dehradun is dedicated to comprehensive glacier research.
In 2007, the Intergovernmental Panel for Climate Change (IPCC) received the Nobel Peace Prize (jointly with Al Gore) for “efforts to disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change.”
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But the 2007 Working Group from the IPCC resulting in much embarrassment when it claimed that “glaciers in the Himalaya are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by 2035 and perhaps sooner is very high.” This was a cut-and-paste quote from a speculative 2005 interview in the popular science magazine New Scientist, and may in fact, have incorporated a typo where “2350” was transformed to “2035”. The IPCC retracted the 2035 claim but it stood by its executive summary of the report.
This month we had an update. Out of 2,767 monitored Himalayan glaciers, as many as 2,184 are retreating, 435 are advancing, and 148 remains unchanged, according to Environment Minister Jayanthi Natarajan. Around 3.5 per cent of glaciated area had seen recession.
This was from a five-year long study, “Snow and Glacier Studies” conducted jointly by the Ahmedabad-based Space Application Centre of Indian Space Research Organisation (SAC-ISRO) and the Geological Survey of India (GSI). It involved 50 scientists from 14 different organisations and covered the Indus, Ganga and Brahmaputra basins in detail.
Data was gathered by various means between 1962 and 2005 in what is undoubtedly the largest ever exercise of the kind. The last few years (2004-2007) is the most reliable since it involved satellite-based mapping at 1:50000 scale. In a second phase project, 2600-odd glaciers will be studied between 2005 and 2010 and this report will probably be ready by end-2011.
A retreating glacier leaves characteristic deposits of stones and soil called moraines, which show the maximum point of glaciation. The GSI states that the majority of Himalayan glaciers are passing through recession, which is a worldwide phenomenon. However, while recession cannot be fully halted or reversed, the effects could be greatly mitigated.
Glacial recession is partly a natural cyclic process and according to the GSI, it has been happening for over a century. Of course, such retreats and advances must be adjusted for seasonal moves and there again, methodology and models will be debated. Comparisons between 1960s data and the recent sat-pictures suggest that there is alarming recession in certain regions.
It is counter-intuitive but cold high-altitude regions are actually at higher risk from temperature change. The IPCC projects an average global warming of around 3 degrees by 2100 at sea-level in some widely-accepted models. But water vapour condenses out at higher altitudes, releasing more heat. Hence the warming in the Himalayas and other mountains could be much higher.
The next SAC-GSI study, which is completely satellite-map driven, will have more reliable data. Until then, it’s good to know that the government is putting some resources into protecting this ecologically delicate and seismically active region.