Dinner will be served by candlelight at many restaurants across the city for the fifth annual Earth Hour.
People all over the globe will participate in this worldwide initiative by turning off the lights and limiting their energy consumption starting at 8:30 p.m. local time.
But Calgary has not performed well during past Earth Hours.
In 2007, consumption for the hour increased by five per cent. The increase was blamed on that evening's Flames game.
