Tens of trillions of global investment dollars are pouring into companies touting robust environmental, social and governance (ESG) credentials. Now short-sellers spy an opportunity.

Such hedge funds, often cast as villains of the piece because they bet against share prices, scent a profit from company valuations they believe are unduly inflated by ESG promises or which they say ignore risks that threaten to undermine the company's prospects.

The fact short-sellers, who look to exploit information gaps, are targeting the ESG sphere underlines the complexities facing investors in accurately gauging companies' sustainability credentials. Teenage climate activist Greta Thunberg last week spoke of CEOs masking inaction with "creative PR."