The causes and effects of sea level rise. Also how and why we know it is occurring.

1. Sea Level Rise
Keygan Sands

2. Causes
 Thermal expansion (1.2-
1.6 mm/yr)*
 Glacial/ice cap melting
(0.4 mm/yr from 1961-
1990, 1.0 mm/yr since
2001)*
 Greenland and Antarctic
ice sheet melting
(greatest potential
contribution, some
uncertainty)*
NASA 2012
*Church 2008

3. Effects
• Coastal flooding and
inundation*
• Storm surge events
(Bay of Bengal
events, Hurricane
Katrina)*
• Coastal erosion (70% of
worldwide beaches are eroded)*
Nicholls 2007
Nicholls 2010
*Church 2008

4. Effects (cont.)
• Aquifer intrusion*
• Habitat
destruction**
• Effects on coasts
heightened due to
existing human
pressures***
WA Dept. of Ecology
Nicholls 2007
*WA Dept. of Ecology
**Galbraith 2002
***Nicholls 2007

5. Effects (cont.)
Nicholls 2007
• Adaptation harder for
developing countries*
• 0.05-0.11m sea level
rise expected by
2100*
• Could be closer to 1m
with new
predictions**
*Nicholls 2007
**Vermeer 2009

6. What has Been Observed?
Church 2008
Nicholls 2010
• 3 mm/yr sea level rise*
Historic:
• Sea level 4-6m higher in last
interglacial period*
• Little net change from 2,000 yrs
ago to 19th century*
• 1mm/yr rise in early 20th
century, 2mm/yr until
recently**
• Trends confirmed by other
data, including sediment
*Church 2008
**Skeptical Science
***Donnelly 2004

7. Erroneous Conclusions
MYTH: sea level rise is exaggerated
Why is this incorrect, besides the observations
proving it wrong?

8. Accurate Predictions/Conclusions
 Must take into account:
 Elimination of “noisy signals”*
 Isostatic adjustment and tectonic
influence*
 Inverse barometer effect*
 El Nino and other oscillations**
 Extra evidence:
 Data agreement (tidal gauge
data, sedimentary
records, satellite data confirm
trends)*
 Mathematical confirmation (98% of
the variance in sea level rise is
explained by increasing global
temperature)***
Nicholls 2010
*Skeptical Science
**Church 2008
***Vermeer 2009

9. Bibliography
Church, J. A., White, N. J., Aarup, T., Wilson, W. S., Woodworth, P. L., Domingues, C. M., Hunter, J. R., and
Lambeck, K. (2008). Understanding global sea levels: past, present and future. Sustainable
Science 3, 9-22.
Donnelly, J. P., Cleary, P., Newby, P., and Ettinger, R. (2004). Coupling instrumental and geological records of
sea-level change: Evidence from southern New England of an increase in the rate of sea-level rise in
the late 19th century. Geophysical Research Letters 31, 1-4.
Galbraith, H., Jones, R., Park, R., Clough, J., Herrod-Julius, S., Harrington, B., and Page, G. (2002). Global
Climate Change and Sea Level Rise: Potential Losses of Intertidal Habitat for Shorebirds. Waterbirds
25, 173-183.
“How much is sea level rising?” Skeptical Science. <http://www.skepticalscience.com/ sea-level-rise-
intermediate.htm>
Huppert, D. D., Moore, A., and Dyson, K. (2007). Impacts of Climate Change on the Coasts of Washington
State. The Washington Climate Change Impacts Assessment chapter 8, 285-309.
Nicholls, R. J., and Cazenave, A. (2010). Sea-Level Rise and Its Impact on Coastal Zones. Science 328, 1517-
1520.
Nicholls, R. J., Wong, P. P., Burkett, V. R., Codignotto, J. O., Hay, J. E., McLean, R. F., Ragoonaden, S., and
Woodroffe, C. D. (2007). Coastal systems and low-lying areas. Climate Change 2007: Impacts,
Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der
Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 315-356.
“Rising Sea Level.” Washington Department of Ecology. <http://www.ecy.wa.gov/climate
change/risingsealevel_more.htm>
Vermeer, M. and Rahmstorf, S. (2009). Global sea level linked to global temperature. PNAS 106, 21527-
21532.
Vinas, Maria-Jose (2012). “Satellites See Unprecedented Greenland Ice Sheet Surface Melt.” NASA.
<http://www.nasa.gov/topics/earth/features/greenland-melt.html>