Launched by the Ministry of Industry and Trade (MoIT) a month ago, the campaign aims to raise awareness about energy conservation and get individuals to make major changes to their lifestyles to battle climate change.

On March 23 from 8.30pm to 9.30pm, every family, organisation and hotel in Vietnam is encouraged to switch off lights and unnecessary electrical appliances to join the rest of the world in observing Earth Hour – a global initiative started by the World Wide Fund for Nature.

Other related activities included a short film competition, collecting people's fingerprints as a commitment to conserve energy and fight against climate change and a group bicycle trip called "Green Movement" where more than 200 volunteers rode bicycles around Hanoi's centre.

As many as 41 films were submitted to the contest, of which the 10 best were screened at the Keangnam building in Cau Giay District. The announcement of the list of the winners is scheduled for March 23.

Danish Ambassador to Viet Nam John Nielsen, Miss Friendly Duong Thuy Linh, and singers Tung Duong and Bao Tram acted as ambassadors for the event, making appearances at several colleges and universities in Hanoi to raise awareness among students about climate change.

"In recent years, Earth Hour has made a significant impression on Vietnamese people's awareness of the causes and consequences of climate change, among which inefficient use of energy is a major contributing factor. It's time we turned this understanding into practical actions to save energy, protect our living environment and build a green, sustainable economy," said MoIT Deputy Minister Le Duong Quang.

He called on every individual to commit to specific, practical daily actions to fight climate change.

Quang said that 2012's Earth Hour helped save 546,000kWh in Vietnam, worth 712 million VND (32,000 USD) – much higher than the 2011 event, which resulted in savings of 400,000kWh.

First introduced in Vietnam in 2009, the event has seen a considerable increase in the number of participating organisations, businesses and individuals. In 2009, only six provinces participated; by 2012, that number had increased to 48.