"Corporate sustainability reporting is becoming more widespread with each passing year, and with that growth comes the need for companies to back up their sustainability claims. The author surveyed sustainability assurance reports from 2013, and the subsequent analysis provides advice for professionals and users.

63% of the world′s 250 largest companies by revenue get their sustainability reports assured, and 70% of those choose a major accounting firm to do so (KPMG Survey of Corporate Responsibility Reporting 2015.)"

[COMMENTARY] It’s good to see so many companies getting their sustainability reports assured. Hopefully, sustainable reporting assurance will become universal in the not-so-distant future. However, in the current deregulatory environment, this might be a challenge. Nonetheless, companies wanting to see their stock outperform will need to satisfy the rapidly growing and large ESG analyst community!
Current State of Assurance on Sustainability Reports, by Sunita Rao, July 2017, The CPA Journal, USA.