Research shows that between 2015 and 2030 the world will need to invest an average of $6 trillion in infrastructure annually. In order to keep global temperature rise below 2°C and prevent the worst impacts of climate change, this infrastructure investment has to follow a model that’s consistent with a low-carbon economy. Figuring out how to secure this vast amount of “climate finance” will require action from the full range of finance actors—from development and commercial banks to climate funds to institutional investors and asset managers.So that’s why the International Development Finance Club (IDFC) and the French Development Agency (AFD), with support from WRI, brought these financial players together at the IDFC Climate Finance Forum earlier this week. More than 120 practitioners took stock of existing climate finance initiatives and aimed to build momentum for more resources ahead of the COP 21 climate summit later this year, an important milestone in the fight against climate change. The day culminated in four outcomes that could help scale up the level of finance going toward mitigation and adaptation projects:1) Harmonizing Principles for Mitigation Finance Tracking.The core group of multilateral development banks (MDBs)—the African Development Bank (AfDB), the Asian Development Bank (ADB), the European Bank for Reconstruction and Development (EBRD), the European Investment Bank (EIB), the Inter-American Development Bank (IDB), the World Bank Group (WBG)— as well as the IDFC, a group of 22 national, regional and international development finance institutions from developing and developed countries, presented a set of common principles to report their climate change mitigation activities.These institutions are major channels of climate finance, and for the first time, they’ll all use a consistent standard for tracking their investments in climate mitigation activities like renewable energy and efficiency projects. This consistency and transparency will make it easier to track progress on financial commitments, while building trust and confidence that climate finance is flowing and will continue to do so.MDBs and the IDFC also agreed to work together towards a similar outcome for climate change adaptation projects, with the aim of making considerable progress by June of this year.2) Mainstreaming climate change within financial institutions.Several IDFC members and MDBs like AFD, Corporación Andina de Fomento (CAF), Japan International Cooperation Agency (JICA), the World Bank Group (WBG), IDB, ADB, AfDB and EIB indicated that they’ll work together to establish a set of best practices for integrating climate change considerations into development finance. Many financial institutions are already mainstreaming climate change into their strategy, programs and operations, but there are no commonly agreed upon principles.Through this collaboration, institutions will have common guidance on how they can set targets for financing climate-related activities, incorporate climate change mitigation and adaptation into their core goals, address organizational structure and staffing issues, and otherwise integrate climate considerations into their operations. In turn, these groups can encourage the broader financial community to scale up their own investments in low-carbon, climate-resilient projects.3) Scaling up climate bonds by demonstrating their impact.Climate bonds are financial products that investors can purchase in exchange for a fixed return on their investment. The bond issuer (e.g. a bank, city/state government, company), then uses the proceeds from investor purchases to fund projects with positive climate impacts, such as energy efficiency improvements or sustainable transport. There’s been a lot of buzz about climate bonds because they present an opportunity to raise new sources of finance at a very large scale to support low-carbon, climate resilient projects.Given the rapid growth of the green/climate bond market in the last several years, bond issuers need to measure their impact in a credible, consistent manner. An informal working group of green bond issuers (AfDB, EIB, IFC and WB) recently developed a harmonized framework for impact reporting on projects supported by green bonds, and at the IFDC Finance Forum, a larger group of climate bond issuers agreed to carry this work forward. Impact reporting will reinforce green/climate bonds’ credibility and build confidence in their impact, which should attract further interest in them.4) Developing common definitions and principles for measuring public-private leverage of climate investments.The term leverage itself has various definitions and interpretations, but in the context of this outcome, the focus is on measuring private sector investment mobilized by public sector finance. In other words, how much private sector money is a public sector financial institution able to attract by footing part of the bill to fund a project? Figuring this out has important implications for how to target limited public resources to ensure effectiveness and impact as well as to achieve the scale of financing required to address the climate change challenge. It will also give developing countries a clearer sense of how much climate finance industrialized nations are mobilizing.Practitioners at the Forum discussed the opportunity to establish common definitions and principles for measuring the public/private leverage of climate investments. As an immediate next step towards a harmonized approach, the MDBs will discuss in greater detail their common approach with IDFC members and other stakeholders in the coming months.As part of their commitment to the United Nations Framework Convention on Climate Change (UNFCCC), developed countries agreed to provide $100 billion per year by 2020 to help developing nations mitigate and adapt to climate change. These four initiatives should help build trust and confidence in the climate finance package in the run-up to the climate summit later this year. Securing this level of finance—and the trillions more required—will be challenging, and will require collaboration between a diverse set of actors. The outcomes at the IDFC event show that while finding common ground can be challenging, it can be done.EDITOR’S NOTE: This blog post was updated on 4/9/15 to better explain the $6 trillion figure referenced in the first paragraph.