Not too long ago, green investing was associated with a warm moral glow, but it wasn’t mainstream--not by a long shot. Increasing climate awareness, a growing shift in policy, and investors demanding socially and environmentally conscious options is transforming this, however, and while it still may not be mainstream, it’s working rather quickly toward mega-trend status. It’s called ESG (environmental, social, and governance) investing, and since its launch in 2007, it’s gone from a nice-to-have to a must-have in the hedge fund industry.