how much could sea level rise in the 21st century
Future sea level The Intergovernmental Panel on Climate Change (2007)[1] projected sea level would reach 0.18 to 0.59 m above present by the end of the 21st century but lacked an estimate of ice flow dynamics calving.[2][3] Calving was added by Pfeffer et al. (2008)[4] indicating 0.8 to 2 m of SLR by 2100 (favouring the low end of this range). Rahmstorf (2007)[5] estimated SLR will reach 0.5 to 1.4 m by the end of the century. Pielke (2008)[6] points out that observed SLR has exceeded the best case projections thus far. These approximations and others indicate that global mean SLR may reach 1 m by the end of this century. However, sea level is highly variable and planners considering local impacts must take this variability into account.
New Orleans A 2007 study by Tulane and Xavier University suggested that "51%... of the contiguous urbanized portions of Orleans, Jefferson, and St. Bernard parishes lie at or above sea level," with the more densely populated areas generally on higher ground. The average elevation of the city is currently between 1 foot (0.30 m) and 2 feet (0.61 m) below sea level, with some portions of the city as high as 20 feet (6 m) at the base of the river levee in Uptown and others as low as 7 feet (2 m) below sea level in the farthest reaches of Eastern New Orleans.[65][66] A study published by the ASCE Journal of Hydrologic Engineering in 2016, however, stated: