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 cannot be (36) .A
detailed study reveals that the lake could release a (37)
cloud of car bon dioxide, capable of wiping out entire communities
around its shores. The warning, from a team of scientists, comes
nearly 20 years after the lake (38) an estimated 80m cubic
metres of CO2 into the atmosphere. Heavier than air, the cloud of gas
rolled down, (39) hillsides and villages. Silent and
invisible, it (40) the air of oxygen, killing hundreds of
cattle and claiming the lives of more than 1,700 people up to 26km away. "It was
one of the most mysterious (41) scientists have ever
investigated" said George Kling, an ecologist at the University of
Michigan. Researchers called in after the 1986 (42)
discovered that the lake, which sits atop a volcano, contained record
levels of carbon dioxide. Gas bubbling up from the Earth’s magma was under
such (43) at the bottom of the 200-metres deep lake that it
dissolved until it reached max. (44) . To
prevent a recurrence, in 2001 engineers installed a pipe to suck CO2 from the
bottom of the lake and release it harmlessly into the air. (45)
. Dr Kling’s team recommends the urgent installation of a further four
pipes in each lake at a rate of one a year. (46) .