Sinking New York

10 April 2011 - New York is a major loser and Reykjavik a winner from new forecasts of sea level rise in different regions. The Intergovernmental Panel on Climate Change (IPCC) said in 2007 that sea levels would rise at least 28cm (1ft) by the year 2100. But this is a global average; and now a Dutch team has made what appears to be the first attempt to model all the factors leading to regional variations. Other researchers say the IPCC's figure is likely to be a huge under-estimate. Whatever the global figure turns out to be, there will be regional differences. Ocean currents and differences in the temperature and salinity of seawater are among the factors that mean sea level currently varies by up a metre across the oceans - this does not include short-term changes due to tides or winds. So if currents change with global warming, which is expected - and if regions such as the Arctic Ocean become less saline as ice sheets discharge their contents into the sea - the regional patterns of peaks and troughs will also change.