In a time where Canada is striving to close the gap between energy production and emissions, it seems fitting to explore how some of our country’s bridges improve urban surroundings and impact the environment.
I’ve seen my share of bridges. Growing up on Vancouver’s North Shore, the Lions Gate Bridge was a fixture of my everyday life. Then school in the Maritimes introduced me to the 13-kilometre drive across P.E.I.’s Confederation Bridge. Now in Ottawa, there seems to be bridges at every turn: foot bridges across the infamous Rideau Canal, road bridges to and from Gatineau and covered bridges tucked away in rural Quebec and Ontario. I’ve always wondered about bridges: do they save energy by making a closer connections from point A to point B? Or are they just another energy-intensive convenience?
In Canada, many bridges are constructed from concrete or steel, which is made from coking coal. As Canada’s dirtiest fossil fuel, coal emits about twice the carbon dioxide of natural gas per unit of energy produced. Compared to hydropower, coal releases about 250 times as much carbon dioxide.
Besides emissions, bridge construction contributes to air and noise pollution, significant bird deaths and severe habitat depletion for fisheries.
But bridges aren’t all bad. Take P.E.I.’s Confederation Bridge. Every year, this bridge replaces the ferry service that would cause the equivalent of 16 million litres of fuel and the release of 44 thousand tons of carbon dioxide.
Confederation Bridge architects received environmental awards for strategically planning the best areas to dump materials dredged up during the bridge's development and creating new lobster terrain as part of a lobster habitat enhancement program. Other rubble was donated to create osprey nesting platforms on P.E.I. shores.
Unlike the Confederation Bridge, the 75-year-old Lions Gate Bridge may not have been considered an environmentally-conscious bridge at the time of its construction in 1938. But the province of British Columbia has since taken efforts to save energy and money where this structure is concerned.
In the early 1990s, there was talk of demolishing the two-lane bridge and building a new crossing, which would support the increased flow of traffic. But in favour of keeping the original design, and saving money and energy, the province decided to resurface the deck, adding a third lane.
Another energy-saving initiative came in 2009, when Vancouver replaced the 170 lights adorning the top of the suspension bridge with LED lights. The new lights have a life span of 10 to 15 years, and save the city $15,000 every year.
Want to learn more? This blog is the first of three this week as Canada celebrates the first ever Let's Talk Energy Week. Continue to follow this blog series and keep up on the latest energy news on the Classroom Energy Diet Challenge website.