Can advertising help save the planet? This week sees the culmination of Hopenhagen, a six-month campaign organised by the International Advertising Association for the UN to raise awareness ahead of the Copenhagen summit

Hopenhagen was launched by UN secretary general Ban Ki-moon at the Cannes advertising festival in June after the UN had approached the IAA last year to create a marketing communications campaign in advance of the UN Climate Change Conference in Copenhagen. Ogilvy New York took on the task following an eight agency competitive pitch in February. CR spoke to Ogilvy worldwide creative director Tham Khai Meng about its idea to "create a people's movement through social media to drive change".

Photographers, designers, filmmakers, web designers and agencies have donated images and work to the Hopenhagen campaign. Corporate sponsors  such as BMW and Coca-Cola have also come on-board. "Hundreds of volunteers are giving their time to this," Meng says. "We are all doing this outside of our day job because we feel that this is the right thing to do. More than US$200m worth of media have been poured into this campaign. It has become massive and global."

The main vehicle for this has been the Hopenhagen website (below) at which over 1.8 million people have signed the UN Climate Petition.

"The original team was Andy Dibb, Will Awdry and myself. I'm New York based and they're London based. Together, we found the idea called 'Hopenhagen'," Meng says. "I then worked with Tom Godici, Greg Ketchum, Michael Paterson (and our creatives) in New York to bring 'Hopenhagen' to life," he explains.

"The idea now lives in TV, Viral, PR, digital, web, social media, press, posters [see video and poster by John Clang shown above], outdoor, guerilla, flash mobs (hundreds of demonstrators stripped off their clothes during Autumn in Copenhagen town square to protest against global warming!), city branding, et cetera. The Mayor of Copenhagen has renamed her city Hopenhagen for these two weeks and the Prime Minister of Denmark opened the UN climate change convention last week by saying, 'Welcome to Hopenhagen!'," Meng says. "The great thing for me is to see and hear the word being used by people, journalists and opinion leaders when they refer to this UN meeting happening right now in Copenhagen."

One of the final creative pieces in the campaign is a film by Tony Kaye (above) in which poet MP from LA appears in various locations around the world spreading the Hopenhagen message. "I spoke to Tony Kaye very early on in this project, about five months ago, and asked if he would be keen to lend his voice," Meng says. "The brief was firstly to send an optimistic message of hope to the world and secondly to drive participation by suggesting to people to sign the petition at hopenhagen.org. To date we have collected more than 1.8m signatures. These signatures will be used to pressure the world's leaders to ratify and seal the deal in Copenhagen."

But what of all the long-haul flights Kaye and his team of three took in making the ad - doesn't this undermine a message about changing our behaviour to combat climate change? "The making of the film could have involved no travelling on Tony's part, but to ratify the green agenda at COP15, the big countries like China, India and the US need to come to the party. We wanted to feature our 'multi-race' messenger of hope in those specific countries - we need them to come to the negotiating table in Copenhagen," Meng says. "This is a call for them, and for developing and developed countries to come and work at the negotiating table to reach a consenus."

In addition, Ogilvy has pledged to offset travel-related carbon emissions through Food and Trees for Africa.

Hopenhagen campaign T-shirt. For more on the project see hopenhagen.org