Earth Hour is “a global event organized by WWF (World Wide Fund for Nature, also known as World Wildlife Fund) and is held on the last Saturday of March annually, asking households and businesses to turn off their non-essential lights and other electrical appliances for one hour to raise awareness towards the need to take action on climate change.”   The observation of Earth Hour began in Sydney, Australia in 2007.  This year, in Sydney harbor, the  Tall Ship Southern Swan is offering an Earth Hour Twilight Cruise, which sure sounds better than sitting at home in the dark.