“Unstable” was the term used to describe the West Antarctic ice sheet by Ohio State University glaciologist John Mercer back in 1968. “Unstoppable” is the term used now. The term refers to irreversible melting of the ice sheet, which is seen as the single largest threat for rapid global sea level rise.

A study led by Eric Rignot of NASA’s jet propulsion laboratory, published in May in the journal Geophysical Research Letters, found that the melting of a major section of West Antarctica’s ice sheet in the Amundsen Sea region cannot be reversed. Back in 1973, a University of Maine researcher, Terry Hughes, wrote a paper, “Is the West Antarctic Ice Sheet Disintegrating?” Hughes later termed the Amundsen Sea area the “weak underbelly of the West Antarctic ice sheet.”

It turns out this “weak underbelly” is large enough to raise global sea levels by 4 feet. But by when? Rignot and his colleagues expect that it could take several centuries for the glacier to fully melt.

Unfortunately, this is not the only source of sea level rise. Prior to the new work on the West Antarctic ice sheet, the most recent U.N. Intergovernmental Panel on Climate Change (IPCC) report estimated sea level rise between 1 foot and 3 feet by the year 2100. Because these projections do not take into account major melting of the Amundsen Sea glaciers, the IPCC’s high-end projections are more likely.

So, what does this mean for our coast, given that half of the U.S. population currently lives near it? It means urgent action is necessary to reduce heat-trapping emissions. It also means adapting at the local level.

Coastal city officials are beginning to think of how their communities will not just survive, but remain vibrant places to live and do business with sea inundation. On Oct. 29—the second anniversary of Superstorm Sandy, Boston launched the Living with Water International Design Competition, an event aimed at rising to the challenge of redesigning cities impacted by rising sea level.

In Maine, the city of Bath is at the forefront of proactive planning. The city recently applied for and won free consulting services from the New England Municipal Sustainability Network in partnership with the American Institute of Architects Design and Resiliency Team (DART). DART is a mix of architects, city planners and engineers from across the country that provides a road map for communities seeking to improve their resiliency and preserve the most valued features.

With the Midcoast Council of Governments, Bath’s City Planner Andrew Deci was instrumental in submitting the successful application to be one of only two cities in the country (along with Provincetown, Mass.) to receive this service.

Bath is ahead of many towns in that it has a comprehensive action plan from June 2009 that takes into consideration sea level rise. The city also participated in a collaborative sea level rise project with the Maine Coastal Program and the Maine Geological Survey in 2013. This was a project of special merit, funded by the National Oceanographic and Atmospheric Association. The mapping data provided through this project indicated that much of Bath’s downtown, the heart of the city, including many historic buildings, would be vulnerable to flooding under the most conservative sea level rise scenario, of just 2 feet, projected by 2064.

The DART team spent three days in Bath in November, hosting a visioning workshop with city officials and residents to share information about sea level rise and learn what community members most valued about their downtown. The experts then produced a proposal for the downtown to address sea level rise and future development and presented the preliminary results to the community (the presentation and report can be found at: www.aia.org/liv_sdat).

Interestingly, very little of the team’s preliminary proposal was defensive. Though the plan did include hardening some edges, they suggested strategies for planning new wetland migration zones, incorporating greenways that could work with the water in the most vulnerable areas of town, and adding green infrastructure in areas of high runoff to naturally filter storm water that will enter the Kennebec. The long term vision was more about embracing the water as part of the community’s identity than trying to keep it out entirely.

“There was a lot of energy in the room, not only about dealing with climate change and water,” said Deci, the city’s planner, “but also making sure that Bath can continue to be the best place it can be.” With final report in hand, he hopes to be able to align the DART teams recommendations with strategies currently in Bath’s comprehensive action plan to prioritize implementation.

So, while we are faced with “unstable” ice and “unstoppable” melting, the problem of sea level rise is not insurmountable. Mitigation and adaptation efforts now will put us in a much better position in the future, perhaps even looking down at the water from our elevated first floor front door. 

Dr. Heather Deese is an oceanographer and the Island Institute’s vice-president for strategic development. Dr. Susie Arnold is an ecologist and marine scientist with the organization.