Serge Orru is advisor to the Mayor of Paris Anne Hidalgo in charge of the circular economy, sustainable development, climate, energy and the environment.

Former head of WWF France (2006-2013), he got close to Anne Hidalgo during the municipal campaign and submitted a report on urban ecology and the circular economy. He was one of the key players in the Grenelle de l'environnement, which was set up by Jean-Louis Borloo. Later, during the 2012 environmental conference, he was a facilitator at the round table on the circular economy.
Serge Orru is also the creator in 1992 of the Calvi Wind Festival, sponsored by Isabelle Autissier and Yann Artus Bertrand.
He is also the initiator of the Stop Plastic Bags campaign which, started in Corsica, has led to a drastic reduction in single-use bags in France (20 billion in 2003 and less than one billion in 2012).
In 2006, he became Director General of WWF France, a position he left on 30 September 2012. Within WWF France, he participated in the creation of a social network: Planète Attitude, in the Earth Hour initiative (1 hour for the planet), in the launch in 2009 of a 3-year campaign: Oui au bio dans ma cantine (Yes to organic food in my canteen), the objective of which is to "encourage the introduction of organic products in collective catering to meet the objective set during the Grenelle Environment Forum to introduce 20 % of organic products in collective catering by 2012".
Alongside many other associations, he participated in the creation of the Alliance for the Planet in 2006.
He is also the author of Pierre Rabhi, Le Fertile, published by Textuel in October 2011.