New social and environmental obligations are now imposed on transnational companies. They are now responsible for the concrete implementation of these obligations and are developing a set of practices to measure, prevent and remedy their environmental impact. These transnational companies (MNCs) are developing corporate transition policies at the frontier of law, management and natural sciences (mapping, indicators, thresholds). These corporate transition policies are constitutive of a new co-produced scientific-normative space and are indicative of the representation of transition that MNCs choose to formulate and transmit to their entire value chain (subsidiaries, subcontractors) regardless of their location. The "Decathlon" case is a perfect illustration: the extra-financial reporting documents, the environmental display methodologies developed and the scientific concepts used but transformed by the company - such as the 9 planetary limits - express "choices". These choices express a corporate scientific policy that constitutes a corporate "normative space". The question raised is that of the methods necessary to objectify these practices: a. STS have proven their usefulness in lifting the veil on these social practices, thus revealing the ontologies co-produced by private actors. The black box of this co-production contains a variety of selected insitutions that allow these companies to formulate credible discourses reflecting a representation of what they consider to be an adequate response to the environmental crisis. b. Transnational law is also important to help describe the techniques by which this regulatory science is constructed by firms: the "choices" of institutions, rules and scientific concepts that construct the normative space of the firm. c. The natural sciences are also essential to evaluate this corporate science, and to distinguish between junk science and good science. The results obtained invite us to make the experiment reproducible by defining this methodology as a new "Earth Law" episteme, at the crossroads of three scientific fields (STS, transnational law and earth science), which together are likely to ensure the effectiveness of the ecological transition by making a standard of "good representation of the environment" emerge in the practices of MCNs.