A number of prominent public buildings across Ireland were plunged into darkness last night as part of Earth Hour.

Millions of people in 7,000 towns and cities across the world turned out the lights at 8.30pm.

Earth Hour is a global initiative which began in Australia in 2007. It aims to highlight the need for action to tackle the world’s environmental challenges, including climate change. Last year hundreds of millions of people worldwide switched off their lights for one hour to demonstrate their support for the protection of the environment.

Landmark buildings including Sydney Opera House, the Bird’s Nest in Beijing, the Eiffel Tower, The Empire State Building, Niagara Falls, and Los Angeles Airport will go dark tonight in a show of solidarity.

In Ireland, the OPW switched off the lights at the Casino in Marino: Trim Castle; Customs House; the Four Courts; Government Buildings Leinster House and the Department of Industry and Commerce

At Blackrock Castle Observatory in Cork, Jeremy Irons’ environmental documentary ‘Trashed’, which received a special screening at the Cannes Film Festival 2012, was screened. It follows the actor as he attempts to discover the extent and effects of the global waste problem.