Shorelines may be in greater peril than thought

Previous estimates of how much the world's sea level will rise as a result of global warming may have seriously underestimated the problem, according to new research.

The study, published in Science, uses a new "semi-empirical" method instead of relying purely on computer modelling. While some modelling significantly underestimates the amount of sea-level rise that has already been seen over the last century, the new method matches the observed rise very closely, says Stefan Rahmstorf, at the Potsdam Institute for Climate Impact Research, Germany, who conducted the new study.

The existing computer model deviates even more from the actual observations built into the new estimates included in a draft of the next report of the Intergovernmental Panel on Climate Change, due to be released in February 2007.

The draft report says newer climate models now suggest a rise only half as great as projected in the previous IPCC report. But that draft may be revised before its release to reflect the new research that suggests the rise will be greater than the IPCC's previous estimate, Rahmstorf told New Scientist.

from New Scientist