One of the many side effects of climate change is rising sea levels. In the last 100 years, sea level has increased 0.6 feet in Portland, while Eastport’s sea level has increased by 0.7 feet. Sea level can rise due to thermal expansion (the ocean gets warmer and expands), volumetric increases (water added to the ocean from melting land-based ice sheets like Antarctica and Greenland), and subsidence (where coastal land sinks or settles). Maine's natural features at risk include bluffs, tidal flats, salt marshes, freshwater wetlands, beaches, dunes, and coastal aquifers.
Much of Maine's population is at risk of being directly affected by the rising sea levels. In 2010, 63% of the Maine population lived in a coastal shoreline county and Maine ranked 8th in the country for the number of seasonal housing units in coastal shoreline counties. From 1980 to 2016, Maine experienced $11 billion worth of damage from coastal natural disasters. In addition to the natural disaster expenses, Maine’s economy will suffer as water levels rise and shorefront properties become inhabitable, public infrastructure becomes stranded or flooded, tourism is affected by changes in beaches and other shorefront parks, the fishing industry shifts harvest species due to habitat loss and species migration, and as other challenges and changes arise.
There are a few ways Maine can address the impacts of sea level rise, including reducing greenhouse gas emissions at local, state, regional, and national levels; strategically investing in new public infrastructure that takes future sea level predictions into account; creating public policy and development regulations in regards to flood zones and storm surge levels; and investing in sea level adaptation strategies.
Climate scientists have identified three main strategies for adapting to sea level rise: fortify, accommodate, or retreat. There are two methods of fortification, hard and soft structures. Hard fortification structures include seawalls, bulkheads, stilts, and other barriers to protect against erosion and rising water levels. However, these hard fortification structures can magnify the effects of sea level rise when installed incorrectly or to properties without the hard fortification methods. Soft fortification methods include sand dunes, salt marshes, flood plains, and other forms of natural protection. Beach renourishment can be a more temporary form of soft fortification but is costly and often needs to be repeated every 5-10 years. Accommodation approaches include raising land and building elevation, installing desalination systems, creating additional drainage systems, and implementing alarm systems to allow upgraded functions to continue in the same location. Retreat involves relocating or abandoning current infrastructure. A site’s current characteristics will influence which strategy makes the most sense economically.
To learn more about sea level rise, interact with NOAA’s Sea Level Rise Viewer.
Join E2Tech and the Gulf of Maine Research Institute for an
interactive presentation to explore the data behind sea level rise
in Maine's coastal communities on February 28th!
CLICK HERE to learn more and register today (space is limited).