Figure 3-9 (a) End-of-century (~2090–2100) estimates for globally averaged sea level rise in meters. Meehl et al. (2007) is based on climate model projections for the IPCC and outlined in black. NRC (1987, 2011, and 2012) is based on synthesis of the scientific literature and shown in light gray. Vermeer and Rahmstorf (2009), Horton et al. (2008), Jevrejeva et al. (2010), Grinsted et al. (2009) are based on semi-empirical approaches and shown in dark gray. Pfeffer et al. (2008) is a calculation of the maximum possible contribution from ice sheet loss and glacial melting and shown in black. (b) Globally averaged sea level rise scenarios developed for the 2014 National Climate Assessment. Present average sea level for the US coasts is determined from the National Tidal Datum Epoch (NTDE) provided by NOAA. The NTDE is calculated using tide gage observations from 1983–2001 and 1992, the mid-point of the NTDE, is chosen as a starting point. (From Parris et al., in press).