For the past few years, I gave clients subject to the Corporate Sustainability Reporting Directive (CSRD) a fairly consistent piece of advice: once you've adopted the European Sustainability Reporting Standards (ESRS), you can probably let voluntary frameworks like GRI go. ESRS drew from GRI, making overlap inevitable, and the original ESRS draft was incredibly comprehensive. It made sense to concentrate all data collection efforts on the disclosure that was not only thorough but legally mandated. Why maintain two reporting architectures when one was required by law?
I've changed my mind for two reasons: how the current ESRS draft has shaped up, and where GRI is headed.
The relief and the loss of simplified ESRS
My reaction to the draft simplified ESRS? It's complicated, and depends on which hat I’m wearing.
As someone who has sat on the inside of a sustainability function, building disclosure programs from scratch, negotiating data collection across business units, explaining to finance teams why they now needed to track new metrics, I understand the profound relief that comes with fewer data points. The original ESRS was staggering in its scope. Thousands of data points. A compliance burden that threatened to consume the very teams and sustainability budgets meant to be driving impact.
But we’re living on an increasingly warming planet, and I know what happens when we strip back accountability requirements in sustainability. The information that disappears is rarely the information companies wanted to share anyway. What gets cut tends to be the hard stuff, but those are the same disclosures that make it possible to actually hold companies to account. The simplified ESRS is definitely more manageable, but has it strayed too far from the original intention of the Corporate Sustainability Reporting Directive?
This tension has me believing that voluntary frameworks like GRI are not the relics of a pre-regulatory era I’d anticipated them to be.
What’s happening with GRI is the inverse of what’s happening with ESRS
Just as mandatory reporting is pulling back, GRI is moving in the other direction.
The new GRI 101: Biodiversity (2024) disclosures, which went into effect January 1, 2026, are case in point. They replaced a standard at a moment when biodiversity has gone from a niche ESG topic to a systemic risk issue with its own global framework, the Kunming-Montreal Global Biodiversity Framework, and its own disclosure architecture in the form of TNFD. GRI 101 asks companies to trace biodiversity impacts through their value chains, understand dependencies on ecosystem services, and align disclosures with the Kunming-Montreal targets. That is a much more significant lift than previous versions of the same topical standard.
The new GRI 102: Climate Change and GRI 103: Energy disclosures, effective January 1, 2027, go further still. GRI 102 is grounded in science-based targets and global climate goals. It incorporates “just transition” metrics — the impacts of decarbonization on workers, local communities, and Indigenous Peoples — that you will not find in most mandatory frameworks. GRI 103 treats energy as a central pillar of climate strategy, requiring disclosures on where and how energy reductions occur across an organization's footprint.
The case for voluntary disclosures
So why maintain GRI alongside mandatory reporting? Three reasons.
Interoperability is now real, not aspirational. One of the strongest arguments against maintaining multiple frameworks used to be duplication. That argument is weakening. GRI 102 and IFRS S2 are now explicitly complementary — companies can use IFRS S2 GHG emissions disclosures to satisfy GRI 102 requirements simultaneously, provided they follow the GHG Protocol and reference the disclosure in their GRI content index. GRI and ESRS E1 are closely aligned. There is a joint interoperability mapping between GRI 101 and TNFD. The frameworks are converging around shared data infrastructure. The marginal cost of staying in the voluntary stack is falling.
Voluntary frameworks set the floor for what comes next. Mandatory reporting does not emerge from nowhere. ESRS drew heavily on GRI. IFRS S2 was built on TCFD. The voluntary standards have consistently been the laboratory in which the next generation of mandatory requirements is developed. Companies that stay close to the leading edge of voluntary disclosure are better positioned when regulators catch up.
What gets measured gets managed. Reporting in accordance with third-party standards drives accountability and, over time, progress. But with a pared-back ESRS and its lack of sector-specific guidance, the most meaningful metrics a company can report on are increasingly found in voluntary frameworks, which are quietly picking up where ESRS leaves off.
What this means for disclosure planning
The companies that will be best positioned in five years are the ones that used the mandatory standards and built on them.
For companies already reporting under ESRS, the path forward is not abandonment of voluntary disclosures like GRI but strategic integration. Map your ESRS disclosures against GRI's updated standards. Identify the gaps where GRI is asking questions that mandatory frameworks are not.
The simplified ESRS reflects a political moment, GRI's updated topical standards reflect a scientific one. The question for sustainability leaders is which reality they want to inform their sustainability disclosures. My belief is that the answer should be both.
