Perched among the highlands of western Cameroon, bordered by
green mountains and cliff faces, Lake Nyos is a scene of
breathtaking beauty. But the picture is deceptive. A detailed
study reveals that without emergency measures, the lake could
release a lethal cloud of carbon dioxide, capable of wiping out
entire communities around its shores. The warning, from a team
of scientists, comes nearly 20 years after the lake belched an
estimated 80m cubic metres of CO2 into the atmosphere. Heavier
than air, the cloud of gas rolled down surrounding hillsides,
engulfing villages. Silent, odourless and invisible, it starved
the air of oxygen, asphyxiating hundreds of cattle and claiming
the lives of more than 1,700 people up to 26km away. "It was one
of the most baffling disasters scientists have ever
investigated. Lakes just don't rise up and wipe out thousands of
people," said George Kling, an ecologist at the University of
Michigan. Researchers called in after the 1986 tragedy
discovered that the lake, which sits ato