Millions of people around the world are being urged to switch off lights for an hour in the biggest climate change protest. This is described as "Earth Hour". It already started in Sydney and China three hours ago. Earth Hour was launched in 2007 as a solo event in Sydney, Australia, with more than two million people involved. Last year's event claimed the participation of 370 cities. Organisers say they want to demonstrate what people can do to reduce their carbon ... Read More