Canadians will be joining millions of others around the globe to mark Earth Hour this evening.    

The World Wildlife Fund, the driving force behind Earth Hour, says 13-million Canadians turned off their lights for an hour last year in the symbolic event aimed at drawing awareness to climate change.    

It's unclear how many Canadians will join the seventh edition of Earth Hour.    

However, Earth Hour is embraced by hundreds of Canadian municipalities and many utilities have Earth Hour sections posted on their websites.    

B.C. Hydro, for example, has a way for many of its customers to compare their electricity use during Earth Hour with their normal power usage.    

Steven Price, a conservation director with the World Wildlife Fund, says municipalities are a driving force behind Earth Hour.    

(The Canadian Press)