S&P 500 and ESG Reporting

Monday, August 9, 2021

Key Takeaways

  • CAQ looked at the most recent publicly available ESG data for S&P 500 companies.1
  • We found that 95% of S&P 500 companies had detailed ESG information publicly available. The information the CAQ examined was primarily outside of an SEC submission in a standalone ESG, sustainability, corporate responsibility, or similar report. Of the remaining 5%, most companies published some high-level policy information on their website.
  • Roughly 6% of S&P 500 companies received assurance from a public company auditing firm over some of their ESG information.

ESG Reporting Period

The timing and frequency at which companies report this information varies. Most commonly, S&P 500 companies disclosed that they report ESG information annually or intend to report annually going forward. Some companies release ESG data in tandem with their annual financial statements while others publish this information at a later time.

As of June 18th, 2021, the CAQ found that:

  • Approximately 54% of S&P 500 companies published ESG data for periods ending in 2020.
  • Roughly 37% of S&P 500 companies published ESG data for periods ending in 2019.

ESG Reporting Frameworks and Standards 

The CAQ examined how many companies referenced five commonly mentioned ESG reporting frameworks and standards – CDP (formerly known as the Carbon Disclosure Project), Global Reporting Initiative (GRI), Sustainability Accounting Standards Board (SASB), The Task Force on Climate Change (TCFD) and Integrated Reporting (IR).

S&P 500 companies used these frameworks and standards to varying extents. Some fully adopted the framework or standard, some partially adopted, and others used the framework or standard as a reference when determining what information to include in their ESG reporting.

Most S&P 500 companies referenced at least one framework or standard. A majority referenced multiple frameworks and standards.

Assurance or Verification 

The CAQ looked at the most recent publicly available assurance or verification statement for S&P 500 companies as of June 18, 2021. More than half of S&P 500 companies (264 companies) had some form of assurance or verification over ESG metrics.

Approximately 6% of companies had assurance from a public company audit firm and 47% of companies had assurance from an engineering or consulting firm (“other provider”) that was not a CPA firm.

Assurance by Public Company Auditors

Third-party assurance from a public company audit firm can enhance the reliability of ESG information. Leading companies who used public company auditors to provide assurance over certain ESG information include: Google, Netflix, Salesforce, Kinder Morgan, Coca Cola, Verizon, UPS, and Johnson & Johnson.

Scope of Assurance: The specific disclosures that S&P 500 companies sought public company assurance over varied. Some companies had assurance over select metrics related to greenhouse gas (“GHG”) emissions and others had more extensive coverage over a wider range of ESG metrics. We used the following categories to describe the assurance coverage:

  • Metrics solely related to GHG emissions,
  • Metrics related to greenhouse gas emissions plus a select number of additional metrics (“GHG+”),
  • Multiple metrics related to a broader range of topics

Most of the assurance reports issued by accounting firms covered GHG and at least a few additional topics.

Assurance Standards: Public company auditor firms primarily used the American Institute of Certified Public Accountants (AICPA) Attestation Standards (including AT-C section 105 Concepts to all attestation engagements, AT-C 205A examination engagements and AT-C section 210A review engagements). However, a few assurance reports referenced the International Standard on Assurance Engagements 3000 (Revised) Assurance Engagements other than Audits or Reviews of Historical Financial Information (ISAE 3000) in addition to or in place of the AICPA attestation standards. One Company noted in their ESG reporting that third party assurance from a public company auditor was obtained, however, the assurance report was not publicly available and the assurance standards applied were not mentioned.

Level of Assurance: Of the companies that had assurance from public company auditors, most of them obtained limited levels of assurance over select information. Three companies obtained limited assurance over some metrics and reasonable assurance over other metrics and two companies obtained just reasonable assurance.

Other Providers

Assurance Scope: Where most assurance reports issued by public company auditors covered more than metrics related to only GHG, most of the assurance or verification from other providers was solely related to GHG metrics. Only 10% of assurance or verification reports from other service providers covered multiple areas.

Assurance Standards: The most common assurance standard referenced by other providers was International Organization for Standardization 14064-3 Greenhouse gases — Part 3: Specification with guidance for the verification and validation of greenhouse gas statements (ISO 14064-3). These other providers also referenced AccountAbility’s AA1000 Series of Standards as well as their own assurance methodology which they commonly stated was based on ISAE 3000. There were eight assurance reports that referenced Tier II of the Environmental Resources Trust (“ERT”) Standard and another eight references to The Climate Registry’s (TCR) General Verification Protocol. None of the other providers referenced AICPA attestation standards.

Assurance Terminology: The CAQ observed that the other providers who were not public company auditors also used terminology such as “reasonable” and/or “limited” assurance in their reports. Additionally, other providers used the term “moderate assurance” in certain reports where the AA1000 assurance standards were used. The breakout of the assurance level referenced by these providers is depicted in the below chart:

 S&P 100 Analysis

In addition to the S&P 500 the CAQ looked at the S&P 100 data separately to understand key trends in this population that may differ from the larger S&P 500 population.

While references to ESG reporting standards and frameworks remained relatively consistent across the population, the CAQ noted a decline in assurance or verification percentages from the S&P 100 to S&P 500. Where 82% of S&P 100 companies had some assurance or verification over their ESG disclosures, only 46% of the remaining 400 companies in the S&P 500 had some assurance or verification. Further 13% of the S&P 100 had assurance from a public company auditor as compared to less than 5% of the 400 remaining companies in the S&P 500.

The CAQ compared the S&P 100 population as of March 12, 2021 to the same population as of June 18, 2021 and observed the following:

  • The number of companies with assurance remained relatively consistent with 80 as of March 12th and 82 as of June 18th.
  • Two additional companies obtained assurance from public company auditors during this three-month time period, increasing the total number of companies with assurance over ESG metrics from a public company auditor from 11 to 13.
  • Where GRI was the second most referenced framework in this population as of March 12, 2021, SASB overtook GRI to become the second most referenced framework as of June 18th.



  1. The data herein reflects the S&P 500 index as of March 12, 2021 and the company’s most recent available ESG information as of June 18, 2021.