Earth Hour is an annual event to to raise awareness towards the need to take action on climate change. Participants are asked to support the cause by switching off lights and electrical equipment for one hour at 8.30pm on the last Saturday of March. Earth Hour started in Sydney in 2007 with approximately 2.2 million people and 2,100 businesses taking part. In 2008, Earth Hour involved 370 cities and towns around the world, including Chicago, Toronto, Copenhagen, Dublin, Atlanta and Bangkok. In 2009, Earth Hour went global with millions of people in over 4,000 towns and municipalities in 88 countries taking part. It also involved landmarks across the world switching their lights off from the Opera House in Sydney to the Eiffel Tower in Paris to Times Square in New York. Tonight, the diners at this restaurant at the The Rocks will enjoy their dinner by candlelight, but this decorative illuminated tree will have its lights switched off.