Do you want ice with that?

Calculating future sea level rises seems to be an inexact science - there are just far too many variables - this however is not a reason for complacency - quite the opposite, when you cannot be sure of the degree to which an effect will manifest then you have to include the conceivable worse case scenario in your planning.

The online version of the journal Science recently published an article titled ‘A Semi-Empirical Approach to Projecting Future Sea-Level Rise’ by Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research. This article suggests that the sea level rise predictions made by the Intergovernmental Panel on Climate Change (IPCC) in their Third Assessment Report (2001) under-estimate the actual likely increases. Using the initial data produced by the computer models of the IPCC and additional empirical information gained through observation, the researchers for this article found that in 2100 sea levels would be 0.5-1.4m above 1990 levels. This contrasts with the 9-88cm forecast made by the IPCC.

The IPCC issue their Fourth Assessment Report in February 2007 and it will be interesting to see how their predictions may have altered.

Meanwhile, why not check out this site which Keith linked me up to, which allows you to see the effect of varying degrees of sea level rise on the geographical location of your choice. And remember this information does not include storm surges, freak storms, hurricane of tsunami effects!

The animation at the top show the predicted decline in Arctic sea ice courtesy of the US National Center for Atmospheric Research. The animation below is one of many put together by the National Environment Trust indicating the possible effects of a combined sea level rise and a storm surge on major US cities - this one is everyone's favourite disaster movie target - New York City: