When Michael Jantzi, founder of Sustainalytics, an esg research firm, started analysing the responsible investing field in 1990, it was a “curiosity, to put it nicely”, he says. To start with, there were “a lot of lean years”. But the ball got rolling with the collapse of Enron, an energy giant, in 2001. Along with other corporate scandals, it gave rise to the Sarbanes-Oxley act, passed in 2002, which overhauled audit and financial reporting for public companies, boosting the G side of what is now ESG.