"In a report released Thursday, the Washington-based, business-backed think tank argued individual companies ’can carry vastly divergent (ESG) ratings from different (ESG rating) agencies simultaneously, due to differences in methodology, subjective interpretation or an individual agency’s agenda.’

…The major ESG ratings agencies analyzed in the report are MSCI, Sustainalytics, RepRisk and ISS…

Concerns raised by the ACCF over the agencies’ ESG rating methodologies included variances in scoring systems among the agencies and the agencies’ not fully disclosing the indicators they evaluate or the material impact of the indicators."

[COMMENTARY]Just like there’s often wide variability in analyst opinions in the interpretation of financial statements, so there should also be variability in ESG opinions. However, setting competitive issues aside, I do agree the rating agencies could be more forthcoming in "disclosing the indicators they evaluate or the material impact of the indicators."
Think tank takes ESG rating agencies to task, by Meaghan Kilroy, July 19, 2018, Pensions & Investments, USA.