Sunday, December 18, 2011

King Tides

The threat of future rising tides is a reality.  This current article in the Times Colonist outlines the potential scenario.

Rolling in the deep: King tide offers vision of 2050 world

Coastal residents can take a peek into the future next week as biannual high tides give us an idea of what may become our normal sea level.
The king tide, the biannual alignment of the sun and moon that creates especially high tides, begins Thursday in Victoria and will continue through Saturday.
"I would encourage everybody to go have a look and see what our world might look like in 40 years," said Roy Brooke, Victoria's director of sustainability.
"I think the higher water is one element, but when you go down there on the 22nd and you see the higher water, you then also have to imagine that higher water combined with a wind storm or wave or a storm surge in the middle of winter. Then you really start to see the reality of what our world might look like in Victoria."
The king tides are not related to climate change. They are extreme high-tide events that occur when the gravitational forces of the sun and the moon reinforce one another when the moon is closest to Earth.
But experts say they demonstrate what the local seashore might look like after higher global temperatures have melted polar ice caps and increased sea levels worldwide.
Rising sea levels have the potential to have serious impacts on local infrastructure as more flooding becomes the norm.
"Practically, it means we could overwhelm some of our infrastructure capacity because it just wasn't built for this. It's built for a cooler world and it's built for a lower ocean," Brooke said. "So some of our lowlying areas could be at risk of flooding and erosion. A lot of our infrastructure in the city is already old and this is going to add an extra burden."
Oak Bay councillors were recently told the municipality will have to spend almost $1 million to combat erosion at McNeill Bay as a consultant's study predicted that it could be as little as 12 1 ?2 years before the water is lapping up within 1.5 metres of the sidewalk.
According to the provincial Ministry of Environment, global sea levels have risen about 20 centimetres over the past 100 years.
As a consequence of warming caused by greenhouse gases already in the atmosphere, sea levels are expected to keep rising.
Climate-change experts says the sea level on the B.C. coast could go up by one metre by 2100.
Three years ago, the provincial government launched the B.C. King Tide Photo Initiative, in which it asked people to shoot pictures of the shoreline at high tide and upload them directly to a website or send them via email.
The aim is to raise awareness and encourage people to think about how they could adapt to a changing environment.
Provincial Environment Minister Terry Lake said: "When you look at some parts of British Columbia, and Richmond is a very good example, where there's a lot of infrastructure, [they] could potentially be at risk if the sea levels begin to rise combined with these types of events and winter storms."