By Alex Rinfret--Islanders can expect to see more frequent high winds, rougher ocean conditions and more storm surges in the future, UVic geography professor Ian Walker said at a talk in Tlell last Thursday (May 18).
Extreme weather events like the Christmas Eve storm of 2003, which destroyed at least one house, temporarily closed down the islands highway, and caused severe damage to the road, will occur here again, and probably within the not-too-distant future, he said.
Weather disasters like hurricanes, floods, droughts and fires are becoming more common all around the globe, he said. They are also causing much more damage, which is partly because there are more people and more buildings around, especially in coastal areas, and partly because they are happening more frequently.
Dr. Walker showed his audience at the Tlell fire hall a graph illustrating the number of weather-related disasters in Canada over the past century. The number rose from just 10 in the first decade of the century, to 130 in the 1990s.
"The Christmas Eve storm is an example of an event we can expect to see more," he said. "This is not a frequent event but it is a probable event."
Scientists attribute the increased storminess to climate change caused by global warming, he said. Global temperatures are currently 1.5 degrees warmer than the long-term average, he said, showing a graph of temperature change around the world over the past 1,000 years.
One and a half degrees might not sound like much, but it's enough to affect all sorts of things, from weather systems to fish migration patterns, he said.
Northern BC and the Yukon have warmed even more than the global average, he said. Canadian records show that since 1948, the average temperature in the north has gone up 2 degrees, he said.
"This is the most rapid rate of warming we've seen in the last 10,000 years," he said, calling the trend "unprecedented".
Other trends observed in BC since 1948 include a 13-day increase in the growing season, a 2 to 6-percent per decade increase in precipitation, and an increase in the ocean temperature.
The east coast of Graham Island is already one of Canada's most vulnerable coasts, Dr. Walker said, which means it is changing at a relatively fast pace. He has been researching the shifting coastline for the past three years, especially the area around Rose Spit.
What he's learned about the past conditions in this area could help predict what will happen here in the future, he said, and how climate change will influence the coastline. One of the reasons this research is important is because people living in the communities of Old Massett, Masset and Tlell will all be affected by the rising sea level. (As will others, but Dr. Walker's study area includes these three communities.)
East Beach is currently eroding at a rate of one to three metres a year, Dr. Walker said, while North Beach is growing seaward by about half a metre a year. Research dating sand dunes has developed a clearer picture of sea level change, he said. About 10,000 years ago, Tow Hill was an island, and it didn't join Graham Island until 3,000 to 2,500 years ago. Rose Spit formed about 1,200 years ago, he said, showing slides to illustrate the changes.
Dr. Walker's presentation was organized by the Graham Island Advisory Planning Commission, and some of his comments were directed to concerns of the commission, like land use planning. Very few land use planning processes in Canada are considering the effects of climate change when they do their work, he said. Here on the islands, a major issue for planners and local governments will be how to deal with property accretion and loss. Other local concerns could be our very vulnerable highway, the potential threat erosion poses to our two airports, and how increased storminess will affect ferry service.
For planners, probability is important. Dr. Walker said he has calculated that the islands have a one in 10 chance of experiencing a storm surge of 80 centimetres in any given year right now. For comparison, the Christmas Eve storm had a similar surge, although it occurred at low tide - fortunately.
"If it had happened a few hours later, it would have been a very different story," Dr. Walker said. "We might not be sitting here."
Audience member Wendy Quinn asked why none of this was considered when the highway was built so close to the sea, and whether Dr. Walker was going to present his findings to the Minister of Transportation and Highways.
Dr. Walker responded that he had to be careful not to be political, and that he is simply reporting his research and conclusions. Members of the public could certainly quiz the politicians and bureaucrats responsible for the highway about it, he said.
The rock which the provincial government has installed at vulnerable spots to protect the highway will not solve the erosion problem over the long term, Dr. Walker said.
"It's a short-term fix," he said. "It could last another 10 to 15 years."
Over the next few weeks, Dr. Walker said he hopes to be doing LIDAR mapping of the coastline with helicopters, which should give a much more precise picture of the topography of the area than is currently available. With that information, the researchers should be able to figure out exactly how a storm surge will affect the coast, and which areas would be flooded.
Dr. Walker said he plans to hold a community forum in the fall to present the results of the mapping.