Since 2017 – On the scale of Greater Paris
Appel d’air is a participative and environmental work by the artist Thierry Boutonnier, which accompanies the Grand Paris Express construction site until 2030. It is based on the concept of landmark trees imagined by the architects Jacques Ferrier and Pauline Marchetti, according to which each of the forecourts of the 68 stations of the future Grand Paris Express metro will have a remarkable tree, a Paulownia tomentosa, whose spectacular blossoming will constitute a recognition signal for users. Appropriating this plant palette to better reveal it, the artist Thierry Boutonnier makes of these landmark trees the witness trees of a social sculpture that gives back its place to the living and the plant in the development policies of the territories and involves the inhabitants in the transformation of the city. COAL will accompany the project throughout its process from 2017 to 2032.

A call for air at the Nuit Blanche Métropolitaine de Nanterre
Forestry boom and participatory workshops at the Climate Academy
Forest boom for the fourth Appel d’air festival
Appel d’air : The workshops
Third Appel d’air adoption party: A day with the trees!
Second Appel d’air adoption party: The flight!
Planting party: first Appel d’air party
The Anthropocene, trees and humans
Thierry Boutonnier’s call for tender for the construction site of the Grand Paris Express
Call for air : Call for participation

  • About us
    About us

    COAL mobilizes artists and cultural actors on societal and environmental issues and accompanies the emergence of a new culture of ecology through its actions such as the COAL Prize, curating exhibitions, advising institutions and communities, European cooperation, and the animation of conferences, workshops and the first dedicated website


    COAL has been awarding the COAL Prize Art and Environment every year since 2010 and the COAL Student Prize - Culture & Diversity since 2020.

  • Projects

    Major projects linked to the major events in political ecology, in connection with natural or urban environments.

  • Artistic direction
    Artistic direction

    About fifty exhibitions throughout France, cultural actions, works in the public space, and project support to contribute to the emergence of a new culture of ecology.


    Cooperation programs on a European and international scale, support for institutions in their ecological transition through tailor-made accompaniment and training, promotion of arts and ecology issues through publications and numerous conferences and workshops.