<br/>Delhi will join other world cities in observing the Earth Hour by turning off the lights for one hour from 8.30 pm to 9.30 pm today. The Delhi government has launched a campaign to make the event a great success by asking shopping malls, hotels, restaurants, educational institutions and major markets to observe the event.<br/><br/>The Chief Minister Mrs Sheila Dikshit will participate in an event at the lawns of the India Gate and switch off the lights there at 8:30 pm. <br/><br/>Our correspondent says that with almost 50 million supporters across the globe and a network in over 100 countries, the annual 'Earth Hour' initiative, organised by World Wide Fund for Nature, has emerged as one of the largest global campaigns to combat climate change The WWF India said that Delhi and Mumbai will be leading the country in making the campaign a success in India. Both the cities had observed the event last year and saved a total of 1,000 MW of power.<br/>