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Role of Silica in Climate Cycles

June 21, 2001

New research from the University of East Anglia (UEA) has demonstrated that the compound silica was not solely responsible for changes in carbon dioxide levels during past Ice Ages.

It is already known from scientific research that during past Ice Ages increased amounts of silica, a common component of wind-blown dust, were deposited in the ocean. This nutrient may have drastically altered the mix of small marine plants in the ocean surface, known as phytoplankton. The end result of such a shift could have been a significant change in ocean chemistry and the lowering of atmospheric carbon dioxide level.

Dr Andy Ridgwell, of UEA's School of Environmental Sciences, used computer modelling techniques to analyse atmospheric carbon dioxide levels over the hundreds of thousands of years of the Ice Ages.

"We found that although silica in the ocean did have an effect on the amount of carbon dioxide in the atmosphere, it was relatively small and wasn't the only factor," said Dr Ridgwell.

"This shows that it's no good pinning the whole climate change story on one single mechanism. Planet Earth's systems for controlling the climate are very complex and we still have a lot to learn about them," Dr Ridgwell continued.

Dr Ridgwell will be presenting his findings today (26 June) at the Earth Systems Processes conference in Edinburgh, organised jointly by the Geological Society of London and the Geological Society of America, which takes place from 24-28 June.


East Anglia, University of