In the presence of the king and queen of Spain and the feel of being at the threshold of turbulent times, the fourth congress organized by the Fundación Arquitectura y Sociedad in collaboration with Arquitectura Viva brought a cast of leading architects to Pamplona, each with a particular interpretation of the event’s ‘Change of Climate’ theme and title. Rem Koolhaas, who attracted droves of journalists, admitted his Europeanist commitment, spoke of the challenges that the abandonment of the countryside poses for western societies, and surprised the audience with the statement that he does not rule out making a leap from architecture to politics. Pierre de Meuron gave a detailed presentation of Herzog & de Meuron’s latest projects. Kjetil Thorsen competently put the work of the firm Snøhetta in the social context, and Jean-Philippe Vassal went through the ecological, economic, and aesthetic ideas that have so coherently given shape to the career of Lacaton & Vassal. Iñaki Ábalos of Ábalos + Sentkiewicz explained his concept of ‘thermodynamic beauty’ and Louisa Hutton, in tune with him, stressed the need to connect sustainability to aesthetics, a conviction also held by Dietmar Eberle. In a fast-paced lecture that was almost like a performance, Winy Maas mesmerized the audience with his utopias, after which Bjarke Ingels, one of the most eagerly awaited speakers, upheld the role of architecture as a force for conscientization. Elaborated on in private interviews, these different but complementary views will be presented in a post-congress book to be edited and published by Arquitectura Viva for release in autumn.