Sub-Sahara swings

ANALYSIS of the fossilised shells of minute lake-dwelling creatures may at least partially clear mankind of causing drought through global warming, according to new evidence from Kingston University.

Jonathan Holmes, a senior lecturer in Kingston's geography department, has used the fossils of ostracods, which live in lakes across the world, to develop a 4,000-year climatic record of Africa's sub-Saharan region which has been in the grip of a drought since the late 1960s.

The composition of fossil ostracod shells varies with water salinity levels and as lake water salinity increases, through evaporation, it is possible to deduce climatic patterns. Using fossils from lake beds in northern Nigeria, Dr Holmes found that the sub-Saharan climate had swung recurrently over the past 1,500 years.

His findings tend to contradict theories that the ongoing drought, and possibly other droughts, are the result of human atmospheric pollution creating a greenhouse effect and global warming.