Could change the face of the fishery, lead to more property damage
Scientists are more confident than ever that human activity is causing the climate to change, and coastal communities will feel the effects during the next century.
A report released in September by the Intergovernmental Panel on Climate Change (IPCC), a body of scientists from around the world, has upped its prediction on how much sea levels will rise by 2100.
Ernest King’s home in Trouty washed downstream about 100 metres as a result of hurricane Igor in September 2010. Scientists expect warming waters will mean more intense storms. — File photo by Barb Sweet/The Telegram
Their previous report, released in 2007, predicted a rise of anywhere between 18 and 58 centimetres. The latest one has found that average ocean levels will rise between 26 and 98 centimetres by the end of the century.
The change was based on the fact that as temperature rises, glaciers will melt faster and add to the volume of water in the ocean, a factor that wasn’t included in the 2007 study.
Norm Catto, a geography professor at Memorial University, has been studying sea level change in Newfoundland and Labrador since 1989. He says the volume of water in the ocean is just one factor affecting sea levels.
Eastern Newfoundland was covered by glaciers — up to a kilometre thick — until about 13,000 years ago. Catto compares the effect a glacier has on the land below it to a spring.
The weight of the ice pressed the land down, and when the ice melted, the land sprang back up again, higher than its previous level. Much of the island is sinking back down after the initial up-spring.
Catto says this is the dominant factor affecting sea level rise in our area. As the ice caps melt, however, the volume of water in the ocean is going to play a greater part.
It’s hard to predict how much melting ice caps will affect sea levels in this province, Catto says, because the IPCC figures are worldwide estimates and are difficult to apply to specific parts of the globe.
“Given that it’s spread all over the world’s oceans … that water (volume) is one additional factor,” he says.
“But as well as that we have glacial history, type of sediment. If we have warmer water temperatures that can cause water to expand. To answer the question for one particular spot, that requires a knowledge of that spot in addition to the stuff that a global report would say.”
A more accurate prediction comes from recordings of tide gauges over decades. Catto and other researchers have compiled 30 years of tide readings from 1,472 locations across the province, and have found that sea levels are increasing at a rate of three millimetres per year in Trinity Bay, with the rate dropping gradually as you go north and west along the coast.
The effect of rising sea levels will be storm surges that reach farther inland, with more coastal flooding and property damage as a result.
Provincial regulations on building near the coast may be too simplistic, according to Catto. The province doesn’t allow new properties to be built closer than 50 metres from the coast. Catto says one limit for the whole province ignores the differences in coastlines. Some are steep cliffs, others more gradual, sloping sandy beaches.
While building a home 50 metres from the coast may be safe in one area, it may be dangerously close to shore in another.
Catto says the province uses the 50-metre rule so no one can say they’re being affected unfairly.
“From a scientific standpoint, it’s not a good approach, but practical politics comes in here,” he says.
“If people are concerned they’ll be treated differently, depending on where they’re at, it might make scientific sense but not political sense.”
As the sea gets warmer, storms will hit harder and more frequently.
Average sea temperatures have risen between 0.6 and 0.8 C around this province since 1901, according to the IPCC report; it’s expected to increase by a further one to four degrees by 2100.
An increase of even one degree can have a major impact on the frequency and intensity of storms we get in the North Atlantic, according to Chris Fogarty, manager of the Canadian Hurricane Centre in Dartmouth, N.S.
Storms feed on warm waters in the Caribbean Sea, and the cold waters of the North Atlantic take that energy away. If the Caribbean Sea is warmer, more storms will form, and if the North Atlantic is warmer, the storms will have more energy when they reach our shores.
“If there’s more warming than usual going on in the Caribbean, then we have a chance of forming hurricanes,” says Fogarty.
“If the waters are cool locally here, maybe even colder than normal, that hurricane is going to weaken quicker as it comes in.”
Fogarty gave the example of hurricane Juan in 2003, which caused $100 million in damage in the Maritimes and was blamed for eight deaths. Before Juan arrived, there was a long period of warm, sunny weather in the Maritimes that warmed the ocean.
“It allowed the hurricane to come in at a little bit higher intensity than it would have had the weather not warmed the waters beforehand,” says Fogarty.
Seven years after Juan, this province experienced its most destructive storm in history. Hurricane Igor caused $200 million in damage and one fatality. The Category 1 storm tore apart roads, cutting off entire communities, and knocked out power for thousands of people.
It’s still unclear whether Igor was a freak event, the likes of which we’ll never see again, or part of a growing trend of fierce storms making their way farther north.
A changing ecosystem
Rising ocean temperatures won’t just affect those who live by the sea, but also those who make a living on it.
George Rose, director of the Centre for Marine Ecosystems Research at the Marine Institute, says warmer-than-average temperatures in recent years have already reduced the amount of crab and shrimp surviving to maturity in the North Atlantic.
“We don’t really understand what the mechanism is exactly, what kills them or stops them from reproducing successfully,” he says. “What we do know is they just don’t reproduce successfully when temperatures get into the range of what they are in a lot of our waters now.”
Shrimp and snow crab are cold-water species, and the two most valuable to the fishery.
In 2012, shrimp and snow crab landings were valued at more than $408 million, 71 per cent of the total value of landings that year. The fishery employed nearly 20,000 people last year.
In the early 1990s, crab and shrimp stocks were booming due to a combination of cold water and low numbers of cod, a natural predator of crab and shrimp, Rose said.
Warmer ocean temperatures create a better environment for plankton, the food for caplin, and caplin are food for cod. While more cod will put increased pressure on crab and shrimp stocks, it may mean a recovery of the species that was the staple of the Newfoundland fishery for centuries.
“This is potentially really good for the traditional systems of caplin, cod, and also some other species we haven’t seen in a long time — like haddock, which seem to me more numerous now than they’ve been in a long time,” Rose said.
The IPCC report blames climate change on CO2 emissions from industry, but predicts reduced emissions will slow, but not stop, rising average temperatures.
Rose’s advice on the fishery might be the best way to deal with climate change in general.
“We’ve got to be smart and look at this in reality,” he says. “We’re not going to change it. Some people say we should cull the cod so crab and shrimp will be there. That’s, in many ways, foolish.
“What we need to do is be smart enough to say this is likely what’s coming. We’ve got to adapt to it and take advantage of it the best we can.”
No more Igor
Hurricane Igor was so destructive that in August the World Meteorological Organization (WMO) took the name off its list of storm names.
Environment Canada asked the WMO to officially retire the name because of the storm’s devastating impacts.
“Hurricane Igor was, by far, the most damaging tropical cyclone to strike the island of Newfoundland in the modern era, causing a fatality and total damage estimated near $200 million,” Environment Canada stated in a news release.
This is only the second time that Canada has asked for the retirement of a hurricane name, the first time being for 2003’s Juan.
The only time there is a change in the list is if a storm is so deadly or costly that the future use of its name would be inappropriate and insensitive.