Pop icon Nelly Furtado lights Toronto during Earth Hour.

Toronto rocked to pop star Nelly Furtado's live concert 'Turn off the Lights' during Earth Hour, as the city joined the worldwide movement for environmental awareness and energy conservation. Before the city switched off lights to mark Earth Hour 8 p.m. to 9 p.m. Saturday, thousands of residents poured into the Nathan Phillips Square in the heart of downtown to enjoy a free concert by the Canadian musician.

Nelly Furtado, a Vancouver-born singer, songwriter and musician of Portuguese origin, is known for experimenting with different sounds, music, genres and vocal styles. The venue was packed to capacity and the media were out in full force. All one could see was camera flashlights when Furtado, dressed in all black, sang 'Turn off the Lights' with a guitar.

Toronto's landmark CN Tower, which till last year was the tallest structure in the world before the Burj Tower in Dubai overtook it, and the famous Rogers Centre switched off lights to mark the token energy conservation hour. Almost all major corporate houses and hotels in downtown Toronto joined the Earth Hour by switching off their neon logos.

Said Mayor David Miller: 'We are proud to be the lead city in Canada fighting to save the environment and supporting the Earth Hour.' Many high-rise condominiums in Toronto and in neighbouring Mississauga switched off power for the worldwide conservation movement launched by the World Wildlife Fund. Millions of Canadians, along with Americans in Chicago, Atlanta, Phoenix, San Francisco and dozen of other communities- small and large - joined mayors, citizens' groups, schools and corporations from coast to coast in switching off their lights.

People from five continents across the globe took part in the Earth Hour to make a statement about the global climate change. The Toronto authorities reported 900 MW less of power consumption in Ontario province - known as the powerhouse of the Canadian economy - during the Earth Hour. About a third of the 300,000 people worldwide who signed an online pledge with the WWF for Earth Hour were from Canada. This is not surprising as the green movement was born in this country and the Green Party enjoys widespread support among Canadians.

Earth Hour was also observed in all other cities across the country.