Big bang：The world can't take anymore CO2.

This guerilla campaign from 2006 is from BUND, the German Friends of the Earth. They want consistent ecological politics.
At this campaign members of the BUND put globe-ballons on exhaust-pipes of cars in Berlin, Germany. The emissions inflate the ballons. And after the message (The world can't take anymore CO2.) is readable, there is a big bang.
Of course the text is not always readable anymore after the big bang but the campaign gives a lot of rumour and media attention.

Agency: Butter.Berlin (Germany)
Creative Director: Timm Holm, Michael Preuss
Art director: Björn von Buchholtz
Copywriter: Hermann Weiss
Photographer: Paul Seitz
Thanks Bjorn for sending