According to Reuters, more than half (58%) of Australian adults turned off their lights to support the second year of Earth Hour on Saturday night (March 29). In an amazing demonstration of the powers of viral marketing, Earth Hour made its way across the globe with an estimated 30 million people taking part worldwide.

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Started in Sydney in 2007 to raise awareness of the effects of our dependency on coal-fired electricity, Earth Hour spread to 35 cities across the globe in 2008. Last year, more than 2.2 million Sydneysiders and over 2100 businesses switched off lights and non-essential electrical appliances, leading to a 10% energy reduction across the city. This year, 30 million people in 35 cities turned off their lights for 60 minutes by the time “Earth Hour” — which started in Suva in Fiji and Christchurch in New Zealand — completed its cycle westward.

Earth Hour aims to encourage people to make changes that will help achieve its ultimate goal of reducing emissions by 5%.