Red Track (C-31): Sea Level Rise and Extreme Weather

- Session Description (click to collapse)

Sea levels have been rising for over the 6000 years since the last ice age.   Current  worldwide sea level rise estimates are  1.8 mm/year, with local sea level rise varying according to  factors such as local glacial isostatic adjustments and other land movements.

Warming of the atmosphere and the oceans creates drivers for increasing the rate of sea level rise.  Melting of glaciers and ice sheets leads to a eustatic rise of sea level, while the warming of the ocean water results in its expansion, leading to a steric sea level rise.  The Intergovernmental Panel on Climate Change (IPCC), a worldwide collection of climate scientists, in 2007 has provided a range of sea level predictions for the next 100 years that exceed the current trend. 

Atmospheric and ocean warming is presumed to lead to increases in storminess and larger wave heights.  Increased storms (magnitude and frequency), with associated larger waves and water levels, would result in larger coastal disasters, exacerbated by increasing coastal populations.

Data gaps include behavior of large ice sheets and climate effects on meteorology.

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- Moderator (click to collapse)

Tony Dalrymple

Tony Dalrymple is the Willard & Lillian Hackerman Professor of Civil Engineering in The Johns Hopkins University’s Department of Civil Engineering. He teaches classes in coastal engineering, civil engineering analysis, and coastal modeling. His research interests include wave mechanics, fluid mechanics, littoral processes, tidal inlets, nearshore hydrodynamics, and coastal processes.

Dr. Dalrymple is a member of the National Academy of Engineering and the National Research Council’s (NRC’s) Committee on Sea Level Rise in California, Oregon, and Washington; the NRC’s Committee on U.S. Army Corps of Engineers Water Resources Science, Engineering, and Planning; the Coasts, Oceans, Ports, and Rivers Institute (COPRI) Coastal Engineering Research Council; and the American Society of Civil Engineers. He has been interviewed by numerous media outlets, including The New York Times (for an article on the New Orleans levees) and CNN (to discuss the 2004 Indian Ocean earthquake and tsunami).


Ph.D., Civil and Coastal Engineering, University of Florida, 1973
M.S., Ocean Engineering, University of Hawaii, 1968
A.B., Engineering Sciences, Dartmouth College, 1967

- Notes (click to collap

People that attended:


Prof. Tony Dalrymple - Moderator/Chair


Sut Soneja - PhD Student in Environmental Health Sciecnes - Recorder


Haiou Huang – PhD in Global Water Program, research staff @ JHSPH, interested in water treatment


William Ball – Environmental Engineer @ JHU – Associate Director of Global Water Program – PI of 5 year intercollaboration of envirommental observatory project


Ashley Matlz – preventative medicine internist – personal interest in sea level rise, mental health aspect is interesting aspect


Don Anderson – APL and Space Dept, NOAA climate office – extreme weather events, generally interested in the topic trying to understand who customers are


Steven Loyld – NASA Goddard – AGU interest, preparing sessions on sea level rise


Steven Babin - Remote sensing of hurricanes, biosystems and ecosystem interaction


Sean Williamson – UMD – Public policy and natural resource economics, Interested in being anticipatory with regard to policy on sea level rise


Bernard Kozlovsky – general interest in environment and toxicology, general learning


Mary Lou McCarthy – finishing MBA @ George Mason, also does work w/ MD dept of Natural Resources


Amanda Trouad – Prof of marine sciences – interweaving remote sensing into non-major courses @ Montgomery College, personal interest as well


Kandas Dalrymple – interdisciplinary faculty support – worked w/ Cindy Parker on the core of these types of grants, general interest


Clifford Mitchell – Asst Director @ MD Env health and food dept



Sea Level Rise: 120m in 20,000 years

6,000 years ago sea level rise is rather slow on global scale (couple of mm per year)


Local sea level rise (aka relative sea level rise)

Effects due to land motion: tectonic effects, post glacial isostatic rebound, anthropomorphic effects, consolidation


2000 tide gages around the world (Permanent service for mean sea level)

Gages concentrated in northern hemisphere – often need to decipher the signal that comes across with regards to annual sea level rise

Don’t have a uniform distribution of tide gauge samples.


2 important corrections to account for: glacial isostatic adjustment (what the glaciers are doing), GPS (looking at changes in land)


Satellites show sea level trends as well: TOPEX/POSEIDON

Can be pretty spotty due to freshwater trends, wind patterns changing, things happening on decayal scales (EL Nino and La Nina) i.e. natural oscillations of the earth


Satellite Topex/Poseidon and Jason-1 – trying to correct out for atmospheric pressure as well


Projecting global sea level rise - GCM models and models of the atmosphere – running giant models, calibrate to past and try and project into the future

Issues around melting glaciers and ice sheets


Comparing satellite observations to IPCC projections seems to be tracking @ upper end of IPCC projections


Other ways to estimate what’s happening in future – leading way is Rahmstorf (2007) – Rate of SLR = a(T-T0), proportional to temperature

Vermeer and rahmstorf (2009) – Rate of SLR = a(T-T0) + b dT/dt, adding instant response


Vermeer and rahmstorf (2009) – basically say SLR is projected to be much more


GRACE satellite – measuring mass of the earth, looking @ local gravity effects, how much ice has been lost with time?

Problem: People that do ice don’t know how much ice is on the earth.


Weakness and data gaps:

Ice dynamics – what we know is based on very few data points

Circulation models (AOGCM) – weaknesses in modeling, in parameters (i.e. how does the vegetation parametized?)

Increased storminess – in terms of storm surge and catastrophic impact of high winds

Data errors – how well do we model the earth to correct tide gauges, how accurate is GPS? Do the errors compound?


Note – Kerry Manuale – storminess issue, is being looked at, specifically targeting extreme events for new IPCC, next IPCC report targeted for next year or so.

Depends on how you define storminess - # of hurricanes that impact coast, severity of hurricane

Also, need to consider regional effects w/ regards to storminess (i.e. El Niño impacts in one region do not impact another).

There are data on wave height info (buoys) evidence that they are increasing. There are people tracking water levels with regards to El Niño’s and La Nina’s. Though may not be bullet proof, but waves are getting bigger in the pacific.

Studies recently in Greenland found significant changes – able to introduce much more agriculture compared to older years

How can conferences relate science better to public? – How can we do it better?

Visualizations that we use are a possible way to bring more attention. Long term it should go back to education, what is the process for science, bring some history into things as well. The cycle of science has to be explained better

Don Henderson - Dept of interior doesn’t care whether its climate variability or climate change – what they were really trying to understand is how do we propagate the information to the consumer/customer?  - What we know about climate vary, what we think the trends are, help them to understand the impacts involved (locally/regionally). How do we communicate our uncertainty in order to people make a mechanical decision?  …Regional climate information is what we call down scaled information – adds more uncertainty to discussion. How do you couple global models to regional models and then to models that are being used by private sectors.

Biggest issue is with glaciologists, in terms of their predictions and margins of error. What’s happening is so much faster than predicted. The error bars are not very useful

How do we engage city councils to get on board? This is the discussion that has to be engaged.

Data on ice and ice dynamics is not a well funded field.

Huge effort in Maryland with regards to adaptation and mitigation for climate change – MD has a plan for this.

Part of the observation of GAIA process – Modelers are up high, policy makers are down low, policy makers are asking completely diffenrtt question then modelers. Error bars to policy makers are completely irrelevant - DO NOT CARE. Building and planning, can never anticipate to that degree, do you build infrastructure to x capacity or y capacity, when it occurs is irrelevant. Return On Investment 5 years/10 years/100years is irrelevant, error bar discussion is masking – lower level people are making decisions at the county level, in some ways the question of how you engage policy makers is being missed when talking about error bars, for policy makers what is the outside range for infrastructure building.

Core of engineers cares – next 100 years, the Navy cares next 100 years – designing for sea level rise, California state govt also cares about long term sea level rise.

If Hopkins wants to engage policy makers, not around the quality of the models, much more useful for Hopkins to engage with MD to engage on local level. Engage in quality of plans not necessarily quality of data– how do I adapt my hammer to my nail. NEPA and environmental impact statements are like nudging the titanic, small incremental changes.

NOAA has setup research activities to engage local communities but this is a small effort relative to the size of the problem. We ought to be looking at ways that NEPA and environmental impact process on says that we can introduce health impact data

Need to see what local agencies needs are. Insurance companies will look long term; govt's do not necessarily look long term.

Communication is a problem in western counties of MD compared to coastal counties – forget words like climate change, use words like variability, to get people to engage.

Alleghany County has all kinds of neat GIS data for watersheds.

Military tends to grab onto issues that may not be recognized as widespread yet. Also have the authority to act on this.

Voters/politicians more apt to listen to Navy (image of conservative organization) – might help bring light to the issue.

You can’t afford to plan for catastrophe.

NUDGE and choice architectures – unfettered access to decision making – this has expended out into IT realms, the Navy, you allow users to have independent of choice and selecting various bundles of goods, but use the behavioral economic nudge to push them in a certain direction. Risk packaging of insurance – what options do we have?



Responses to local sea level rise:

Harbor infrastructure

Coastal communities (shoreline recession greater than sea level rise) – sand renourishment costs millions of dollars in doing it, tend to do more each time we do it, process that is getting more and more expensive, do we retreat communities or do we try and armor communities- retreat, armor or do nothing -> these are our options to protect coastal cities.

Coastal transportation: vulnerability for highways, etc. coastal infrastructure in general what are we going to do

Wetlands: Louisiana loses almost 30 sq miles of wetlands per year- going on for about 100 years. Wetlands around USA are getting smaller and smaller, what tare we doing about saving them?

Salinity intrusion: As salt water gets higher it’s going into estuaries


More than just inundation there is also erosion that has to be considered with regards to sea level rise.



Do we allow wetlands to exist in places they weren’t before, lot of political pushback on this.

Zoning – Why don’t we zone people out of hazardous areas? Louisiana build levees and people move into hazardous areas.

State of MD is spending lot of money to keep certain islands from disappearing (islands disappear and reappear) – not necessarily taking sea level rise into account.

Some areas in MD that are zoning and buying land back to push people out to protect against SLR.

Salinity intrusion – Cliff – you have to look @ secondary effects , all commercial agriculture production is hugely at risk, all on well water, vulnerable to salinity intrusion.

Louisiana is now recognizing that land is getting lost, realistic on that they are losing land, the core of engineers have built some amazing facilities in record time – spending immense amount of money to meet 2011 deadline.




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