1. Panel Regarding Sea-Level Rise Donald F. Boesch Public Policy Forum March 10, 2010

2. MVN RSM Program Sea-Level Rise Panel Don Boesch – Univ. Maryland Center for Environmental Science Craig Fulthorpe – University of Texas Institute for Geophysics Tim McGee – RADM US Navy (retired) Dave Jansen– House Natural Resources Committee Staff

3. MVN RSM Program Gauges Measure Relative Sea-Level Measured by tide gauges

4. MVN RSM Program Relative Sea-Level Trends http://tidesandcurrents.noaa.gov/sltrends/sltrends.shtml Baltimore 3.1 Pensacola 2.1 Grand Isle, LA 9.2 Galveston 6.4 Sitka, AK -2.1 Los Angeles 0.8 0 0.2 0.4 0.6 -0.2 -0.4 -0.6 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Charleston 3.2 Global ocean mean 0.18 Sea level (m) relative to 2000 San Fran. 2.0 Sea level rise rates over the periods of record indicated in mm/yr

5. MVN RSM Program Post 19 th Century Sea-Level Rise 3.2 +/- 0.4 mm/yr (1993-present) Church et al. 2008

6. MVN RSM Program Global Sea-Level Rise http://sealevel.colorado.edu/ Satellite altimeter

7. MVN RSM Program Sea-Level Rise Is Not Uniform

8. MVN RSM Program Accelerated Loss of Land Ice Velicogna 2009 GRACE gravity field measurements 1980 1985 1990 1995 2000 2005 2010 Cumulative mean annual mass balance reference glaciers all glaciers Continental Glaciers

9. MVN RSM Program Closing the SLR Budget Murphy et al. 2009 ARGO JASON-2 GRACE Cazenave & Llovel 2010

10. MVN RSM Program Semi-Empirical Projection of SLR IPCC (2007) projections Vermeer & Rahmstorf (2009) method Linear projection @ 3.2 mm/yr

11. MVN RSM Program New Findings Since IPCC AR4 Altimeter trends (>3 mm/yr) vary with climate but continue. Contribution of polar ice sheets and glaciers is increasing. Regional variability due to non-uniform thermal expansion. Kinematic constraints on polar glaciers likely constrain SLR to 2 m during this century, more likely around 0.8 m. Submarine melting important in ice sheet mass loss. Empirical models based on temperature projections suggest 20 th century SLR at least twice that of IPCC. 6 m or more of SLR over several centuries likely to be locked in as a result of 21 st century warming.

12. MVN RSM Program Vulnerable Coastal Landscapes North Carolina DE NJ MD DC VA

13. MVN RSM Program Some Critical Needs Sustained ocean observing system, particularly in areas influencing ice sheets. Models capable of reliable projections of land-ice melting and thermal expansion. Coastal system models capable of projecting inundation, tidal exchange, storm surge, estuarine ecosystem dynamics, and wetland and landform responses. Socioeconomic decision-making tools to inform adaptation decisions.

14. boesch@umces.edu www.umces.edu/president/ “Science is a way of trying not to fool yourself.” Richard Feynman