Climate change adaptation and mitigation strategies are gaining visibility and support. Decision-makers are defending the extension of large infrastructures that are low greenhouse gas (GHG) emitters, as a way to act quickly and massively without calling into question existing economic models. This situation depoliticizes these projects, masking their other ecological consequences such as their impacts on biodiversity. This article examines how promoters of these projects depoliticized its socio-technical futures while other actors re-politicized them. Using the example of the Seine Nord Europe Canal project, we show a politicization of the territorial future and a depoliticization of the environmental future. This depoliticization is based on the techno-optimist discourse promoting large-scale infrastructures as the only possible solution to the global ecological and climate crisis. It uses a selective framing of the environment that makes some elements visible and others invisible. We conducted semi-structured interviews with biodiversity stakeholders in the territories that would be impacted by the canal. Based on the concepts of environmental forms and motives, we reconstructed the environmental ontologies ignored by the dominant discourse and assembled them into three alternative scenarios. We present the method of investigation and identification of these motives and discuss the likelihood of the constructed scenarios participating in a re-politicization based on the reactions of various actors.