The document discusses the need for an International Green Bank (IGB), also known as the Global Investment Trust for Clean Energy, to help mobilize $100 billion per year in climate finance and $500 billion in annual private investments for clean energy projects in developing countries. It argues that while multilateral development banks will play a role, they have limitations that require a new institution focused solely on providing low-cost, long-term financing to lower energy costs and attract more private investment globally for clean energy at scale. The IGB would work to complement existing sources and help overcome political and market barriers to mobilizing financing needed to address climate change.