What is Sustainability Reporting?

Thirty years ago, sustainability reporting was a fringe activity practiced by a small minority of corporations. In 1992, the global output of these reports amounted to a mere 26 documents.¹ Fast forward to 2026, and we have witnessed major adoption. What began as an experimental venture has now become a "near-universal expectation",^{2, 3} with the world's 250 largest companies (G250) now maintaining a 96% reporting rate.⁴

Defining Sustainability Reporting

Sustainability reporting is the public disclosure by organizations of their economic, environmental, and social impacts. Unlike traditional financial reporting, which centers on financial position and profits for capital providers, sustainability reporting extends accountability to a broader set of stakeholders. These include employees, communities, and regulators.^{5, 6}

Most definitions converge around the Triple Bottom Line (TBL): the three pillars of People, Planet, and Profit.^{7, 5} While companies use overlapping labels such as ESG reports, Non-financial reports, or CSR reports, the industry in 2026 has largely standardized around the term "Sustainability Reporting." This shift is driven by a desire to move away from the politicization of "ESG" and toward the more holistic, scientifically grounded language used by the EU's Corporate Sustainability Reporting Directive (CSRD) and the International Sustainability Standards Board (ISSB).

Why Do Companies Report?

Why would a company invest significant resources into disclosing non-financial information? Academic research points to a cluster of recurring motivations that have evolved alongside the practice itself.

1. According to legitimacy theory, organizations report to ensure they are perceived as operating within the bounds and norms of their respective societies.⁸ Reporting signals a commitment to societal values, which can lower perceived risk and enhance a firm's "social license to operate".⁹

2. Stakeholder theory suggests that managers have a duty to provide a transparent account of how profits are generated and at what cost to the environment or society.¹⁰ In this view, reporting is a tool to reduce "information asymmetry" and provide investors and NGOs with the data they need to make informed decisions.¹¹

3. More recently, signaling theory has been used to explain how high-performing companies use superior disclosure to distinguish themselves from competitors. By revealing high-quality, assured data, firms signal their strategic resilience and long-term value to capital markets.¹²

The 2026 Landscape

The journey of sustainability reporting has moved through three distinct phases: the experimental era of the 1990s, the standardization era of the 2000s (led by the Global Reporting Initiative), and our current regulatory era. Today, disclosure is no longer a differentiator; it is a compliance obligation for large firms.^{13, 14}

The current global reporting infrastructure is built upon three gravity centres:

1. The Global Reporting Initiative (GRI): Created in 1997, the GRI remains the most widely used framework globally, used by 77% of the G250.⁴ It focuses on impact materiality, that is, how the company affects the world. A landmark 2025 agreement ensured GRI's interoperability with investor-focused climate metrics, allowing companies to satisfy multiple standards with a single data set.

2. The ISSB (International Sustainability Standards Board): The ISSB has rapidly become the "Global Baseline" for financial markets. As of March 2026, 36 jurisdictions representing over 60% of global GDP, including Australia, Brazil, and Japan, have adopted or are incorporating IFRS S1 and S2 standards.

3. The EU's CSRD and the 2026 Omnibus Shift: Europe remains the most rigorous regulator, though the EU Omnibus I Directive recently narrowed the scope of the CSRD. By raising thresholds to companies with over 1,000 employees and €450M in turnover, the EU reduced the mandatory reporting pool from 50,000 to roughly 10,000 of the largest firms. Despite this, 81% of companies not subject to the law still intend to comply voluntarily to maintain their competitive advantage.¹⁵

The Challenges of 2026

As the field matures, the academic and practitioner focus has shifted from "whether to report" to "whether the report can be trusted."

Despite the push for digital transformation, 74% of companies still rely on spreadsheets as their primary sustainability reporting tool.¹⁶ This creates significant challenges for assurance readiness, as firms move from limited assurance to the more rigorous reasonable assurance required by modern auditors.

A growing body of research cautions that disclosures can sometimes serve self-interested legitimation purposes, where firms selectively reveal favorable info to justify their actions.¹⁷ In 2026, stakeholders are increasingly using AI-driven tools to cross-reference corporate claims against satellite data and supply chain records to spot "greenwashing" in real-time.

Conclusion

Sustainability reporting has crossed the threshold from a niche project to a cornerstone of the global financial system. With over 275,000 reports currently archived in our database, the sheer volume of data is staggering.

For the modern organization, a sustainability report is no longer a static PDF published once a year. It offers dynamic, strategic data that informs business strategy, manages supply chain risk, and builds long-term trust with a global audience.

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References

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12. Reber, B., Gold, A., & Gold, S. (2021). ESG disclosure and idiosyncratic risk in initial public offerings. Journal of Business Ethics, 179(3), 867–886.

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14. Farooq, M. U., & Muhammad, H. (2025). Climate governance and sustainability reporting. Corporate Social Responsibility and Environmental Management, 32(4), 5430–5445.

15. Workiva (2024). European Sustainability Reporting Survey.

16. PwC (2024). Global ESG Reporting Survey.

17. Roszkowska-Menkes, M., Aluchna, M., & Kaminski, B. (2023). True transparency or mere decoupling? The study of selective disclosure in sustainability reporting. Critical Perspectives on Accounting, 98, 102700.