Private equity firms are investing billions of dollars from US public sector workers' retirement savings into fossil fuel projects that contribute over a billion tonnes of greenhouse gas emissions annually, according to a recent analysis. Since 2010, these firms have invested more than $1 trillion (£750 billion) in the energy sector, acquiring both established and emerging fossil fuel projects. The analysis highlights that many of these investments operate with limited financial transparency due to exemptions from various disclosure requirements, allowing them to function largely out of the public eye.