Sea Levels Are Rising Threat to Historic Districts
We used to talk about climate change in the future tense—how a warming earth might be changed in, say, 50 or 100 years. Today, while the future is still concerning, the present has also muscled its way into the discussion, whether we’re talking about the bleaching of Australia’s Great Barrier Reef, the extreme drought/flood cycle plaguing California, or the early cherry blossoms that burst forth during Washington D.C.’s record warm February only to wither in the cold of mid-March.
Kelsey Robertson, a 2016 graduate of Georgetown University’s graduate program in Urban & Regional Planning (URP), is concerned about the present and future effects of climate change, but she is also cognizant of its effect on our shared past: Specifically, on the more than 100 mapped historic districts in the cities and towns located along the shorelines of the Chesapeake Bay and its tributaries.
“Protecting historic resources from climate change is not just important in order to preserve the cultural site, but also for community resilience,” Robertson wrote in her master’s thesis, which recently won the 2017 Dick Wolf Prize from the Capitol Hill Restoration Society. “Historic resources are integral to a community’s collective identity and function as places of memory and meaning for residents, especially in the wake of a disaster.”
In her thesis, and in the Dick Wolf Lecture she delivered to the Society on March 24, Robertson said planners need to create new processes to mitigate the threat that climate change poses to historic sites.
In order for this to happen, Robertson cited four prerequisites: Officials and the public must have accurate data on sea-level rise; state and federal governments need to provide technology and expertise to confront these challenges; the public must become more educated on the impact of climate change; and historic preservation procedures must be flexible enough to respond to climate change’s unique challenges.
Robertson is now Government Affairs Manager for AVANGRID, a renewable energy developer and utility. For her thesis, she took an in-depth look at vulnerable historic districts in three coastal cities: Annapolis, Md., and Alexandria and Norfolk, Va. She used geographic information system (GIS) modeling to compare various data sets, which included the location of historic districts, data on flood-prone areas, and other information.
“The impact of a changing climate is going to be location-specific,” with some communities more affected than others, said Joshua Murphy, a Senior Geospatial Analyst for the National Oceanic and Atmospheric Administration (NOAA) who teaches GIS mapping at Georgetown and was Robertson’s thesis advisor. “It means you can’t just talk about a blanket, holistic approach at a national or state level.”
“Robertson’s thesis was place-based and highly technical, looking at specific ways in which the separate disciplines of climate science and historic preservation could work together to protect historic places,” said URP Faculty Director Uwe Brandes. “It concentrated on those areas of the three cities that are among the most historic—and the most vulnerable to sea-level rise.”
Occasionally, a dramatic event will highlight the dangers of climate change. For the Chesapeake, one such event happened in October of 2010, when the last house on Holland Island succumbed to rising sea levels and fell into the Bay. Other changes—such as coastal flooding that has always occurred but is now happening with more frequency and intensity—are more incremental indicators of changes to come.
“It’s proceeding so slowly that it makes it hard for people to act now,” Robertson said. “And yet, it is happening now and we must act.”