Climate change in Tantramar means four things:
1 Temperature rise
2 More extreme storm events more often
3 Sea level rise
4 Changing precipitation patterns
Warmer temperatures may extend our growing season, but animals and crops may not respond well. Unfamiliar pests and diseases may spread into our region, such as deer ticks and Lyme disease. The maps below show the average temperatures for New Brunswick in the past and potential increases in the future.
More Extreme Storms More Often
The Tantramar Region has seen extreme storm events in the past. Storms which overtopped or broke the dykes and caused flooding were witnessed in 1759, 1869, 1903, 1904, 1906, 1909, 1917, in the 1930s and 40s. The 1759 storm resulted in floods that damaged houses and delayed British settlement. The most famous storm to affect the Tantramar area was the Saxby Gale, which hit on October 4-5, 1869.
It flooded low-lying areas and overtopped the dykes by about 0.9 m. The following are accounts of the aftermath on the Tantramar Marshes.
Accounts of the Saxby Gale, 1869
There was fearful destruction of property all through the New England states … doing great damage to the Sackville Marshes, and also all of the Bay of Fundy coast; destroying hundreds of tons of hay, washing away cattle of all descriptions, horses, oxen, sheep and pigs. Barns full of hay were taken on the water for miles. Sunken
Island was literally covered with haystacks, cattle, sleepers, fences, telegraph poles, gates, boards, and numberless other articles, used by farmers on the marsh … In the morning all was quiet but rather foggy; the farmers looked towards their marshes in silent amazement. Source: W. K. Bowser diary in the Mount Allison Archives
Barns and even small schooners were driven up on high land and dykes were torn down in all directions, necessitating a heavy expense. Farmers lost nearly all their hay which was in stack (there being few barns on the marsh at that time) along with cattle and sheep pasturing on the marshlands. One particular incident happened in which a mare and her nursing colt floated on a haystack bottom across the Bay of Fundy to Rockport, alive and well. With extra work and expense, the farmers got the dykes rebuilt and gathered enough hay to get through the winter and stock came out well. Source: http://heritage.tantramar.com/WFNewsletter_10.html
1962 Freshwater Flood
A more recent storm occurred on April 3, 1962. After heavy rains, Sackville was impacted by severe fresh water flooding. The height of the flood was estimated to be 8.0 m. Lorne Street in Sackville was completely flooded from the CN Station to Bridge Street. At Black’s Hardware Store (now Bowser’s Construction Ltd.) the water was over a metre deep.
The graph below shows the frequency and intensity of hurricanes and tropical storms to hit the Tantramar area since 1900. In the last decade there have been several serious storm events in the region. Storm surges often accompany these events and can cause considerable damage. For example, two storms hit Port Elgin in 2010 with extensive damage estimated to be around $900,000.
What is a 100-year storm?
A 100-year storm (1:100) is severe and will cause major flooding but it is not a storm that occurs every 100 years. It is a storm that has a 1% chance of occurring each year. So it is rare but it could occur every year. Similarly, a 10-year storm (1:10) is less severe and has a 10% chance of occurring each year. A 5-year storm is much more likely to occur each year, but could also occur several times a year. Climate change is causing more severe storms to happen more often.
Sea Level Rise
Sea levels are rising because of:
• Melting polar ice caps and glaciers
• Expansion of warmer water molecules in the oceans
• Coastal lands are slowly sinking
Coastal lands are sinking because land in the middle of the continent is still in a process of rebounding from glaciers that retreated after the last ice age approximately 10,000 years ago. This has gone on for thousands of years, and is not related to today’s climate change, but this very slow continental movement will worsen the impact of storm surges and sea level rise for coastal communities.
How Much Will Sea Level Rise in New Brunswick?
Scientists’ best prediction is that by 2025 sea level is expected to rise by around 14 cm compared to what it was in 2000. By 2055 it will be about 40 cm higher and by the end of the century it is predicted to be 100 cm (1 metre) higher.
Source: Daigle, 2011 & New Brunswick Climate Change Secretariat, 2012a
What is a storm surge?
Storm surges are usually caused by low pressure and are an increase in the tide level compared to what was predicted. New Brunswick coasts most often feel the impacts of storm surges during powerful late fall and winter storms, and from hurricanes. Storm surges are worst when they coincide with high tides. Because of sea level rise, worst-case flood levels could happen much more often.
Like rising global temperatures, sea levels have been rising for a long time too. The graph below shows how the ocean level has been rising at Saint John since 1939 (when measurements began).
Find out more about sea level rise, check out these studies:
Sea-Level Rise and Flooding Estimates for
New Brunswick Coastal Sections
By Réal Daigle (2012)
Sea-Level Rise Estimates for NB Municipalities
Le Goulet, Saint John, Richibucto, Sackville,
By Réal Daigle (2011) http://atlanticadaptation.ca/node/203
Sea Level Rise and Flooding: What they Mean
for New Brunswick’s Coastal Communities
Lee, Caroline and Daigle, Réal (2012)
Changing Precipitation Patterns
Changes to climate will affect precipitation patterns around the world. While other areas are expected to get drier, in New Brunswick we can expect an increase in total annual precipitation. This increase in annual rain, snow and freezing rain is anticipated to fall in fewer, but more intense events, which may lead to flooding and erosion. The maps below show the total annual precipitation between 1971 and 2000 and the potential average for the future.