The field of Environmental Finance captures the entire spectrum of financing, trading, and investment approaches that has the objective to reduce emissions, scale capital allocations, and reduce material environmental risk in portfolios, while driving "green growth". Once mainly focused on carbon markets (emissions trading) and CleanTech investing, environmental finance has become an entrepreneurial innovation space with applications encompassing the entire finance value chain, and all investment vehicles.According to the UN-Principles of Responsible Investment (UN-PRI), as of 2014, $ 48 trn. of global assets under management (AUM) incorporate Environmental, Social, and Governance (ESG) mandates in investment decision-making. This renders sustainability investing one of the single largest investment mandates, crossing all asset classes, including (public and private) equity, credit, and bond markets. Even though dedicated CleanTech venture capital (e.g. Khosla Ventures) and sustainability investing (e.g. Generation Investment Management) started a decade ago, most of the shift has taken place in the last half decade alone.Importantly, the shift towards environmental finance has driven new entrepreneurial opportunities in financial innovation of green technologies, assets, and economic growth. Examples such as green crowd lending and crowd equity investments, solar microfinance, and innovating financing models such as Clean Power Finance have led the way. Green bond issues, options on mispriced (stranded) assets, shadow pricing of asset risk to capture market signals and drive change in corporate behavior were non-existent just a few years ago.