Since the 1990s, the question of the contribution of digitalization to the ecological transition has been raised again and again, without any clear conclusion being reached. This initial link between digitalization and sustainability could stem from a transfer of the economic concept of dematerialization to the emerging concept of the information society. However, the first institutional studies, even if they point to a clear potential, are much more cautious about the concretization of emission reductions. At the start of the new millennium, industry players took up the issue, based on the optimistic principle that digitalization was by default more part of the solution than the problem, and produced numerous reports with extravagant estimates of potential avoided emissions. This rhetoric found its way into political institutions such as the European Union, which has institutionalized the concept of twin transitions: that the digital and ecological transitions must go hand in hand. Recently, a major effort led to the production of new methodologies for assessing the net environmental effects of digital solutions. This impetus accompanies a more profound movement in Europe toward the financialization of sustainable economic activities, of which the digital sector is determined to be a part.