By Dr. Adam Fenech, Director, Climate Lab, University of Prince Edward Island
The challenges to Prince Edward Island in addressing climate change are many – perhaps the most important being the impact of coastal erosion through storm surges and high water levels. We know, for example, that shorelines across PEI often experience erosion – a wearing away of the land by water, waves, ice, and wind. It is anticipated that climate change will bring more intense storms, rising seas and reduced sea ice coverage (which normally protects the shore from wind and waves). Coastal erosion will continue and likely become more severe, threatening public and private infrastructure at great economic cost. But by how much?
Last week, the Climate Research Lab at UPEI, in partnership with Dr. Nick Hedley of Simon Fraser University, launched a new tool for understanding the threat of coastal erosion, sea level rise and storm surges to Prince Edward Island. CoastaL Impacts Visualization Environment, known as CLIVE, is a video game programmed by two of our students – Alex Chen and Andrew Doiron – that uses a digital elevation model (DEM) together with high resolution aerial photos to provide a three dimensional landscape to depict scenarios of past and future environmental change. Yes, a video game; albeit a serious one. CLIVE is an example of an emerging approach to activating communities to respond to future climate changes through the use of visualization techniques.
CLIVE allows users to fly over the Island using a game controller, and to trigger the raising or lowering of sea levels to examine which areas of PEI are vulnerable to storm surges and flooding. Also immersed in the science that built CLIVE are the results from coastal change studies conducted over the past few years. Tim Webster from the Nova Scotia College of Geographic Sciences, and Carl Brydon from PEI’s own GeoNet Technologies, conducted a study a few years ago using aerial photos from 1968 and 2010 to examine every meter of PEI’s coastline. The study concluded that, on average across the Island, the annual rate of coastal change was 28cm of erosion (land wearing away or lost to sea). There were areas of accretion (adding land to the Island) but overall was erosion.
Wanting to know if this was significant, a group of concerned scientists including Carl Brydon, Randy Angus from the Mi’kmaq Confederacy of PEI, Erin Taylor from the PEI Department of Environment, Labour and Justice, Steve Dickie from the PEI Office of Public Safety, Don Jardine, a private consultant, and myself conducted a further study examining the risk to infrastructure – roads, buildings, bridges – of future coastal erosion. The annual rate of coastal change was multiplied by 30 years, 60 years and 90 years for each meter of coastline to provide a sense of what PEI’s coast would look like in the future under current rates of change. The results are worthy of our attention.
Over the next 90 years, over 1,000 existing residential homes (about $160 million worth using an average housing price of $159,000), 8 barns, 7 gazebos and 42 garages are at risk from coastal erosion. Seventeen of our iconic lighthouses will need to be moved away from the shore for fear of damage. 146 commercial buildings, 5 waste water treatment settling ponds and even 1 wind turbine are shown in our study to be vulnerable. Over 50 kilometres of roads (about $50 million worth using an average rate for road replacement) are also at risk to coastal erosion. And remember, this study examined risk under current rates of coastal erosion. All of our knowledge tells us that coastal erosion will increase as a result of rising sea levels, lowering landforms (coastal subsidence) and an increase in coastal storms.
Not all coastal change is erosion. Our study showed that from 1968 to 2010, some PEI coasts grew about 15 square kilometres through accretion of land. Unfortunately, during that same time period, about 35 square kilometres were eroded, giving PEI coasts a total net, or overall, loss of about 20 square kilometres. While this represents only one third of one percent of PEI’s total land area, it is still almost 5000 acres, or almost half the size of Charlottetown. And it represents a thin band of valuable land around our coastlines. Our study results allow us to conclude that yes, Mr. Premier, your province is shrinking!
Questions? Contact Adam Fenech at afenech@upei.ca or (902) 620-5220