How much has global sea level risen in the past 100 years, how much will it rise in the next 100 and why is it rising anyway?
Global-average sea level is believed to have risen by between 10-20 cm during the past century (e.g. see the change at Newlyn in above figure which is typical of many records worldwide) and best estimates are that it will rise by approximately 50 cm in the next 100 years (i.e. an acceleration of a factor of 3 in the rate). Rising sea levels are largely a consequence of the thermal expansion of the ocean, melting of low latitude glaciers (Alps, Rockies etc.) and many other factors, each of which are reviewed every few years by the Intergovernmental Panel on Climate Change (IPCC) . 8. How will a rise of 50 cm affect the UK? As an example, a rise of 15 cm in sea level on the east coast of England, where there are extensive areas of low-lying land, roughly doubles the probability of over-topping a coastal structure (such as a sea wall) due to tide and storm surge. Consequently, a rise of 50 cm (i.e. approximately 3*15 cm) would result in an order of magnitude (i.e. 8-fold) increased probab
