Former World Bank Chief Economists Justin Yifu Lin, Alan Gelb and I argue that the June 2023 Paris Development Finance Summit missed a crucial element: To mobilise private capital at a scale significant to climate change, multilateral development banks need to find ways to work much more closely with pension funds and other institutional investors that hold about half of global financial assets.  We propose a new Global Climate Finance Facility, majority owned by pension funds and other institutional asset owners while drawing on MDBs’ knowledge and experience across a broad range of geographies and sectors.