Since 2015 the European Union has positioned itself as global leader in the ecological transition, placing the goal of carbon neutrality by 2050 at the heart of its economic and financial agenda. However, achieving this ambition requires massive and long-term investments, raising the critical issue of how to finance them. This article examines the role of public banks, particularly the European Investment Bank (EIB), in structuring the financing of the green transition. Adopting a historical and theoretical perspective, the article first defines the strategic role of public banks in financing long-term investments and traces the evolution of the EIB’s investment strategy within EU sustainable finance framework. Then it offers a critical assessment of the growing reliance on private capital mobilization which tends to subordinate ecological goals to market logic. The article explores several reform pathways from incremental institutional adjustments to more ambitious transformations. It notably proposes that national public developement banks be organized in a European network to finance such investments as infrastructure. It also proposes a framework linking the European Central Bank (ECB) and public banks, allowing the latter to finance long-term sustainable projects via linkage to money creation. In a more ambitious move, the article proposes to establish a green securitization platform capable of channeling massive resources toward verifiable sustainability goals and supporting the internationalization of the euro within a progressive financial architecture. The originality of the article lies in its articulation of institutional critique with operational redesign. It seeks to reposition public banks as central drivers of long-term investment, in coordination with central banks, while accounting for the geopolitical dimensions of monetary sovereignty. In doing so, the article contributes to a broader rethinking of public finance as a key lever for a just and effective ecological transition in the European Union.
