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

Panel Regarding Sea-Level RisePanel Regarding Sea-Level Rise

Donald F. Boesch

Public Policy ForumMarch 10, 2010

MVN RSM ProgramMVN RSM Program

Sea-Level Rise PanelSea-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

MVN RSM ProgramMVN RSM Program

Gauges Measure Relative Sea-LevelGauges Measure Relative Sea-Level

Measured by tide gauges

MVN RSM ProgramMVN RSM Program

Relative Sea-Level Trends 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 0.80

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

lev

el (

m)

rela

tive

to

200

0

San Fran. 2.0

Sea level rise rates over the periods of record indicated in mm/yr

MVN RSM ProgramMVN RSM Program

Post 19Post 19thth Century Sea-Level Rise Century Sea-Level Rise

3.2 +/- 0.4 mm/yr (1993-present)

Church et al. 2008

MVN RSM ProgramMVN RSM Program

Global Sea-Level RiseGlobal Sea-Level Rise

http://sealevel.colorado.edu/

Satellite altimeter

MVN RSM ProgramMVN RSM Program

Sea-Level Rise Is Not UniformSea-Level Rise Is Not Uniform

MVN RSM ProgramMVN RSM Program

Accelerated Loss of Land IceAccelerated Loss of Land Ice

Velicogna 2009

GRACEgravity field measurements

1980 1985 1990 1995 2000 2005 2010 Cu

mu

lativ

e m

ea

n a

nn

ua

l ma

ss b

ala

nce

reference glaciers

all glaciers

Continental Glaciers

MVN RSM ProgramMVN RSM Program

Closing the SLR BudgetClosing the SLR Budget

Murphy et al. 2009

ARGO

JASON-2

GRACE

Cazenave & Llovel 2010

MVN RSM ProgramMVN RSM Program

Semi-Empirical Projection of SLRSemi-Empirical Projection of SLR

IPCC (2007) projections

Vermeer & Rahmstorf (2009) method

Linear projection @ 3.2 mm/yr

MVN RSM ProgramMVN RSM Program

New Findings Since IPCC AR4New 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 20th 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 21st century warming.

MVN RSM ProgramMVN RSM Program

Vulnerable Coastal LandscapesVulnerable Coastal Landscapes

North Carolina

DE

NJ

MD

DC

VA

MVN RSM ProgramMVN RSM Program

Some Critical NeedsSome 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.

• [email protected]• www.umces.edu/president/

““Science is a way of trying not to fool yourself.”Science is a way of trying not to fool yourself.” Richard FeynmanRichard Feynman