Coastal Processes and Environments Under Sea-Level Rise and Changing Climate: Science to Inform Management

by Laura Guertin

From April 14-19, 2013, in Galveston, Texas, 80 professionals from 11 countries gathered for an event for the record books. This week marked the first-ever Joint Penrose/Chapman Conference, titled “Coastal Processes and Environments Under Sea-Level Rise and Changing Climate: Science to Inform Management.” A very clear set of objectives were set for the group: (1) To provide a forum for discussing the latest advances in coastal systems response to both natural and anthropogenic influences; (2) To generate a consensus statement from this esteemed, international body of scientists that coastal change is occurring now and in many areas at an alarming pace; and (3) to assure that the outcome of this meeting is conveyed to the general public and to policy makers.

Did we accomplish these goals? Well… let’s start from the beginning.

My name is Laura Guertin, and I’m an Associate Professor of Earth Science at Penn State Brandywine in Media, PA. My Ph.D. is in marine geology and geophysics from the University of Miami’s Rosenstiel School of Marine and Atmospheric Science. My dissertation research involved creating an integrated chronostratigraphy and sea-level history of the Late Cenozoic mixed carbonate-siliciclastic sediments of the south Florida platform from a series of continues cores drilled in the Florida Keys and Everglades National Park. My recent research has gone on more of a pedagogical tangent, but after I saw the title of this Penrose/Chapman Conference, I knew I had information I could contribute, and even more information I could learn.

The conference agenda included 51 talks, 29 posters, 1 panel discussion, and 1 field trip, across a range of categories. Talks focused on the record of sea-level rise, examined case studies of the coastal response to sediment supply, explored coastal evolution in carbonate environments, and integrated field results and modeling. The talks were filled with approaches, risks, and scenarios for exploration. For example, since 1930, there has been a 10-inch rise in south Florida sea level. And with a projected 16-inch sea-level rise in northern California, the runways at San Francisco airport will be submerged. Besides these sound bites, there were some powerful closing statements to talks, such as the talk that examined sand transport dynamics in the lower Mississippi River and an exploration of sustaining the landscape. The speaker concluded that, “unless society is willing to abandon deltaic landscapes, engineering diversions that disperse sediment to build land are necessary to counter future land loss.” For some people, this statement may seem straightforward, but when you put the supporting data and images behind this statement, then the statement becomes a powerful message that can be shared with scientists and non-scientists alike, and perhaps trigger a call to action.

Although there were several presentations focusing on the Gulf of Mexico coastline, several international locations were presented as case studies for challenges and successes in coastal management. For example, the Philippines, coastal erosion is prevalent and severe in many places, but it is not yet recognized as a national issue. There is only one geologist in the Philippines working on coastal erosion! In the Dutch coastal system, they are able to successfully secure sand from the North Sea, which has large volume of sand available, to build a sand buffer for coastal renourishment. And in the Ganges-Brahmaptura tidal delta, flooding is not necessarily a “bad thing,” as communities in this region have figured out how to cope and exist with periods of flooding and non-flooding.

The field trip took the group along the coast from the former Brazos River Delta to the east end of Galveston Island and focused on the Holocene evolution of the coast and current changes that are due to acceleration of sea-level rise, limited sediment supply and human influence. Evidence from flooding, channel construction, and even modern-day dune migration was visible along the way. One of the exciting parts of the field trip for me was to finally visit and be able to stand on top of the Galveston Seawall, a structure I teach about in my Natural Disasters course when discussing the 1900 Galveston Hurricane.

While I was in Galveston for the week, I was blogging daily for my students back at Penn State Brandywine (http://journeysofdrg.org). I teach introductory-level Earth science courses for non-science majors, so I kept my postings at a more basic science level (leaving out the terms “paraglacial” and “ecomorphodynamic,” for example), but always including some take-home messages from each day.

This phrase was one of my points from the first day of the conference: At the end of the day, the group agreed there are components of sea-level rise we have consensus on, and some parts that we do not. We still have a lot of work to do, and we need to continue to communicate as clearly as possible what we do know.

This phrase was from my post on the last day of the conference: In the end, we all agreed that we need to emphasize to policy makers that decisions have to be made with existing uncertainty. We also agreed that we as scientists need to get involved with policy by serving on boards/committees and communicate more with the public.

I’m sensing a theme here….

So, if I go back to the beginning of this post, where I ask if we accomplished the objectives set by the conveners, where do we stand? The conference was certainly successful in allowing scientists to communicate the observed and modeled complexities within local-to-global coastal environments. We as scientists are now informed, energized, and ready to move forward even more than we already are with our communications to policy makers and the general public. Be sure to keep an eye out for the conference “consensus” statement developed by the conference participants in future issues of GSA Today and EOS. And with the challenges and complexities in coastal environments, I am sure this is not the last time you will hear from this group.

Hats off to the conveners of this first-ever Joint Penrose/Chapman Conference! The hard work and efforts of these trailblazers were essential in gathering such a dynamic group for an important discussion on the dynamics of our coastal zone: John Anderson (Rice University); Margaret Davidson (NOAA); John Geissman (Univ. of Texas at Dallas); Gary Hampson (Imperial College, London); Denise Reed (The Water Institute of the Gulf); Torbjörn Törnqvist (Tulane University).