Sea level rise is predicted by the IPCC to be 18-59 cm by end-century, but physical measurements since its last report suggest that it is happening faster than anticipated. New estimates suggest upper limits in the range of well over a metre by end-century (Rahmstorf 2010). The consequences are loss of human habitation, including some densely populated areas, loss of farmland, loss of valuable ecosystems, salination of water tables and increased vulnerability of coastal populations to the natural disasters of storm surges. These losses will potentially result in large scale population movement into, for the most part, already densely populated areas. Nigeria and Bangladesh are the most worrying examples, with the possibility of 10s of millions affected; others are the small island states such as Maldives and Tuvalu which face the prospect of eventual loss of their national territory and need for total relocation.