New financial tools are emerging alongside new technology to help companies address greenhouse gas emissions. Unlike green bonds, where the proceeds from the bond are used for new and existing projects with environmental benefits, sustainability-linked bonds can be more flexible.  NRG Energy announced the issuance of a $900 million sustainability-linked-bond earlier in December. The company says that is going to help them achieve a 50% reduction of absolute greenhouse gas emissions by 2025 and reach net-zero GHG emissions by 2050 from a 2014 baseline.   Gaetan Frotte, the senior vice president and Treasurer at NRG Energy, spoke with Energy Evolution co-host Taylor Kuykendall about the latest announcement.