Brown clouds and ice

13.11.08 19:11

Even while the President-elect of the USA, Barack Obama, was on Wednesday signalling likely new environmental legislation, the Director General of the Indian Meteorological Department (IMD), Ajit Tyagi, was claiming that glaciers in the Himalayas are at risk of disappearing by the year 2035.

While this timetable is likely to be questioned, there is evidence of an accelerated rate of glacier-melt at the roof of the world. One example is Kolhai glacier in Kashmir, one of the largest glaciers in the Himalayas. According to Muneer Ahmad of the National Geophysical Research Institute in Hyderabad, India, the nose of this glacier receded by nearly 22 metres in 2007, while several smaller examples have disappeared completely.

It is easy to rush out the phrase ‘global warming’; it has been claimed, for example, that the celebrated snows of Kilimanjaro are disappearing because of warming, but this is more likely to be due to a paucity of precipitation (including snow) across that part of Africa than increased melting. Even so, this might still be indicative at least of some sort of shift in climate.

In the case of the Himalayas, warming of some description does seem a likely culprit, particularly given the extent of the infamous ‘Atmospheric Brown Clouds’ (ABCs), three of which are suspended across Asia. These are clouds of pollutants up to three kilometres (1.8 miles) thick which have a complex effect on the atmosphere, alternately masking and magnifying climate change.

As the clouds drift across the continent they deposits particles of soot. The United Nations Environment Programme (UNEP) reports that black soot has been noted around the base of Mount Everest at concentrations more typical of cities. Darker surfaces absorb more light and heat, and this might be one cause of the glacial melting.

Should glaciers disappear as quickly as feared then there would be serious repercussions; the glaciers form a constant reservoir of fresh water that feeds the major rivers of South Asia, such as the Ganges, the Indus and the Brahmaputra. Without the glaciers the flow of these rivers would become seasonal, leaving the livelihoods and lives of tens of millions of people swinging between flood and drought.

By: Stephen Davenport