Activists prepare to climb the Sagrada Familia, Gaudi's master-work, in Barcelona. The activists hold a banner reading 'Zapatero: Stop Climate Change' (Zapatero: Paremos el Cambio Climático). Greenpeace holds the action on the first day of UNFCCC Climate Change Talks in Barcelona. These meetings are the last negotiating session before the historic UN Climate Change Conference in Copenhagen in December 2009 (COP15). Greenpeace demands a strong international climate change treaty.