Celebs who supported Earth Hour

Earth Hour is an annual international event started in 2007 by the World Wide Fund for Nature(WWF). Take a look at the stars who've supported the initiative: Vidya Balan is the latest to join the Bollywood bandwagon of stars who've supported the 'Earth Hour' initiative. Vidya was recently announced the brand ambassador of WWF 'World Earth Hour-2011'.(Pic: Viral Bhayani)

Actor and brand ambassador of 'World Earth Hour-2011' Vidya Balan during an interaction with the media in Mumbai recently. (PTI/Vishal Kelkar)

Vidya Balan urged Indians not just to switch off lights during Earth Hour 2011, but to go beyond it and protect the earth from the issue of climate change.(Pic: Viral Bhayani)

Delhi observed Earth Hour from 8.30 pm on March 26, 2011. (Pic: Viral Bhayani)

Actor Abhishek Bachchan, the brand ambassador of WWF's Earth Hour 2010, urged Indians to switch off lights for one hour as part of the initiative to support action on climate change. (BCCL/)

Delhi Chief Mnister Sheila Dikshit and actor Abhishek Bachchan at the launch of World Wide Fund's Earth Hour 2010. (BCCL/Sanjeev Rastogi)

Bollywood perfectionist Aamir Khan has also been the brand ambassador for 'Earth Hour' initiative previously.

Kannada film actress Ramya and singer Raghu Dixit along with N Sivasailam, Managing Director, Bangalore Metro Rail Corporation (L), pledge their support for Earth Hour 2010. (BCCL/)

Ramya and Raghu Dixit pledging their support for Earth Hour 2010. (BCCL/)