Three competing plans to dissuade companies from exaggerating their green credentials could lead to more frustration and costs for businesses, especially starting next year.

Over $3 trillion has flowed into investments specifically touting their environmental, social and governance (ESG) credentials reported under scores of voluntary disclosures, stoking regulatory concerns about "greenwashing."

While investors and companies want a single set of mandatory disclosures to aid comparison between firms and keep down reporting costs, three draft sets of disclosure rules are currently out for public consultation from the European Union, the U.S. Securities and Exchange Commission, and a new Group of 20-backed International Sustainability Standards Board (ISSB).