Australia's iconic Sydney bridge and opera house plunged to darkness on Saturday, putting on a spectacular show for those taking part in Earth Hour 2010.
Many people took candlelit picnics to watch the city landscape go black. Those who were on hand to watch were also treated to a fireworks display.
Earth Hour is a global event in which homes and businesses turn off their lights for one hour to take a stand against climate change. The initiative began in Sydney back in 2007 and has since spread to all seven continents.
'I think it's very important obviously for us to take a moment and think about our impact on the environment and our place in making positive change for the planet to go forward,' said one Sydney resident.
'It's a way of uniting people for the cause of climate change and raising awareness,' said another.
Yesterday, more nearly 300 cities across Canada went dark for Earth Hour – more than in any of the other 115 countries participating.
If you participated in Earth Hour, we'd love to see how! Upload your photos to our 'Your Weather Gallery.' You can find it under the Related Links section above.