The 70ft iconic statue of Bapu at Gandhi Maidan joined the elite league of monuments - from Harbour Bridge in Sydney to Big Ben in London - in the city's first-ever effort to raise awareness on climate change by participating in Earth Hour on Saturday.

Lights on the Mahatma Gandhi statue were switched off from 8.30pm to 9.30pm on Saturday as also in several other buildings across the city.

Besides prominent buildings, all offices and establishments of the state energy department in the city also dimmed their lights to promote the cause of energy and environment conservation.

Several residents too, showed enthusiasm in observing Earth Hour by switching off their non-essential electrical appliances between 8.30pm and 9.30pm on Saturday night. "I switched off the lights at my home during Earth Hour and played ludo with my father during that time. I also used that time to talk to my friends and spread awareness about climate change by sending text messages to others," said Abhishek Kumar Shrivastava of Chaukshikarpur in Patna City.

Energy department secretary Pratyaya Amrit expressed satisfaction over Earth Hour observations in Patna. Pratyaya claimed that this was the first year when such a campaign was taken up in the state and around 400 families in the city had responded to the SMS texts sent by state power distribution companies.

"The response of Earth Hour in Patna was quite satisfactory. Even though participation in the event was voluntary, we are glad that around 400 people joined the cause. The idea behind observing Earth Hour is to bring a behavioural change in people to save energy and contribute towards prevention of climate change. We had a good beginning in this regard in Patna on Saturday night, for which I am thankful to all those who participated in the cause," said energy department secretary Pratyaya Amrit.

Gaya district magistrate and ex-officio chairman of Bodhgaya Temple Management Committee Sanjay Kumar Agrawal too expressed satisfaction over the lights-off event at Mahabodhi Mahavihara.

"We received good response as a number of monks and tourists also came to Mahabodhi Mahavihara when we switched off the lights during Earth Hour. We are going to make it an annual event from now on and ensure that the entire Bodhgaya participates in it," said Agrawal.

Earth Hour is an annual international movement spearheaded by the World Wide Fund for Nature (WWF), which urges individuals and business establishments across the globe to turn off their non-essential lights and electrical appliances for an hour at the appointed time to raise awareness on climate change. Pratyaya claimed that the state energy department would undertake rigorous campaign next year to persuade more people to join the cause. "We would hold prior meetings with all stakeholders including government agencies, private organisations, educational institutions and individuals to apprise them on Earth Hour and its benefits. We would try to ensure that lights are switched off at least on important buildings like Raj Bhavan, chief minister's house and museum among others," he said.