In what sounded like a farewell speech, U.S. Securities and Exchange Commission Chair Gary Gensler on Thursday defended his agency's controversial regulatory approach of treating cryptocurrency as a security and calling for corporate disclosure of climate impact.

Cryptocurrency represents 5% to 8% of the SEC’s enforcement efforts, Gensler said at the Practising Law Institute’s 56th annual conference on securities regulation. He added that his focus has been on the tens of thousands of digital assets that courts have ruled are offered or sold as securities.