Earth Hour started in 2007 when the WWF-Australia inspired 2.2 million individuals and more than 2,000 businesses to turn off their lights for one hour to take a stand against climate change.

The event has grown ever since. In 2011, Earth Hour saw hundreds of millions of people across 135 countries switch off for an hour, with 43 per cent of Canadians – about 15 million people – turning off their lights.

Participants continue to grow worldwide. The NHL will be dimming the lights at 10 games this year. Musical composer Andrew Huang will be performing a special "Earth Hour Anthem" at Toronto's Earth Hour bash.

Manitoba will be turning off non-essential lights in urban and rural government-owned provincial buildings. Emergency lighting and security systems will remain on as usual. All provincial employees have been asked to turn off computer monitors and lights in workspaces before leaving at the end of the week and are invited to participate at home as well.

"Turning lights off for one hour alone won't resolve the climate change issue but it does demonstrate that individual action can make a difference," said Conservation and Water Stewardship Minister Gord Mackintosh. "Consider reducing your carbon footprint even more by unplugging unused electrical appliances on an ongoing basis and walking or taking a bus to work."