29 March 2007The Independent
Notorious for its annual floods, Bangladesh may seem the last place in the world to worry about a drying up of the rivers that flow from the Himalayas. But the country is as much at risk from drought as it is from flooding. Already farmers who used to grow rice have turned to farming prawns because the water in their fields has turned so salty nothing will grow there.
Bangladesh is the front line of global warming, with rivers drying up, and increasingly common freak weather conditions that include out-of-season tornadoes and tides that have stopped changing. The entire country is one huge delta, formed by the Ganges, Brahmaputra and Meghna rivers. Flooding may seem to be Bangladesh's greatest enemy, but in fact the rivers are its lifeline. They are the main source of fresh water for a country where agriculture represents 21 per cent of the economy. And environmentalists fear that if the Himalayan glaciers melt, the rivers' flow will reduce drastically.
Most people tend to think the main risk in Bangladesh is a catastrophic flood from rising sea levels. But the country has a defence against that: a series of dykes along the coast which should be able to withstand predicted rises in the sea level. There is no defence against drought.
Professor Ainun Nishat, one of the country's leading climate experts, says it is the melting of the Himalayan glaciers that worries him most - more than rising sea levels or changing local weather patterns. "At the moment, we're probably seeing a slight increase in the river flow because of [the glaciers melting]," he says. "But what happens in two to five years when the glaciers are gone?"
The north-west faced an unprecedented drought last year, after the annual monsoon rains failed completely. Farmers had to resort to pumping ground water to survive, but they fear the ground water will dry up if the rains fail again.
In the south-west, trees in the famous Sundarbans wildlife reserve, home to the world's largest remaining population of wild tigers, are dying out - and falling river levels may be one reason. Bangladeshi scientists believe the trees are dying because of rises in salinity levels in the mangrove swamps. That could be because rising sea levels are inundating the swamps, but it could also be that the river flow has reduced in recent years.
So far, the reduction in flow is purely due to dam projects upstream in India. But experts fear the loss of fresh water would be far more drastic if the Himalayan glaciers melt and the rivers start to dry up. Already Bangaladesh is fighting a losing battle against rising salinity levels. Its farmers can only produce 8 tonnes of rice per hectare, compared with 17 tons in China.
Faced with potentially disastrous effects on agriculture, the country has come up with a strain of rice that grows in salty water.
"We are fighting climate change on the front line," Professor Nishat told The Independent earlier this year. "But the battle has to be integrated across all countries."
Bangladesh has good reason to feel aggrieved at global warming. Its annual carbon emissions only 0.172 tons per capita, compared to 21 tons in the US.
If the rivers dry up, it would leave Bangladesh completely at the mercy of the rains.
