Navigating the Data Deficit Why Professional Estimates Are Essential for the Future of Global Sustainability Reporting

As global capital markets undergo a historic shift toward mandatory environmental, social, and governance (ESG) disclosures, a significant structural hurdle has emerged: the widespread unavailability of high-quality, primary sustainability data. Across the world’s most complex industrial value chains, the information required to satisfy new regulatory requirements is frequently incomplete, shrouded in uncertainty, or entirely non-existent. Despite these gaps, the momentum for transparency is irreversible. Regulators, institutional investors, and a broad spectrum of stakeholders are no longer requesting but demanding clear, decision-useful information regarding corporate sustainability performance. This has created a critical tension at the heart of modern corporate reporting, forcing organizations to determine how they can provide credible insights when the underlying data remains in a state of evolution.

The Imperative of Progress Over Perfection

The traditional corporate mindset of waiting for "perfect" data before making public disclosures is increasingly viewed as a liability rather than a prudent safeguard. For many global organizations, the current challenge is not a lack of corporate will or strategic ambition, but rather a systemic lack of mature data collection infrastructure. Sustainability reporting is still in its formative stages, and while progress is being made, globally consistent measurement methodologies for complex metrics—such as Scope 3 carbon emissions or biodiversity impact—are not yet fully mature. In the current reporting environment, uncertainty is no longer an anomaly; it is the operational norm.

Against this backdrop, the use of estimates has transitioned from a temporary workaround to a fundamental necessity of the reporting process. Whether drawing on proxy data, third-party industry benchmarks, or sophisticated assumptions based on existing financial and operational information, organizations are increasingly reliant on estimates to construct a coherent picture of their sustainability footprint. Without the strategic application of these estimates, many of the disclosures required by new international standards would be functionally impossible to produce. The central debate in boardrooms and finance departments has shifted: the question is no longer whether estimates should be utilized, but how they can be deployed responsibly, transparently, and with the necessary rigor to maintain market trust.

The Regulatory Chronology and Evolution of Disclosure

To understand the current reliance on estimates, it is essential to trace the rapid evolution of the sustainability reporting landscape over the last decade. The journey from voluntary "Corporate Social Responsibility" (CSR) brochures to rigorous, audited financial-grade disclosures has been accelerated by several key milestones:

• 2015: The Paris Agreement and the TCFD: The United Nations Climate Change Conference (COP21) and the subsequent establishment of the Task Force on Climate-related Financial Disclosures (TCFD) created the first major framework for linking climate risk to financial stability.
• 2021: The Formation of the ISSB: During COP26 in Glasgow, the International Financial Reporting Standards (IFRS) Foundation announced the creation of the International Sustainability Standards Board (ISSB). This marked the beginning of a move toward a "global baseline" for sustainability disclosures.
• 2023: Release of IFRS S1 and S2: The ISSB issued its first two standards: IFRS S1 (General Requirements for Disclosure of Sustainability-related Financial Information) and IFRS S2 (Climate-related Disclosures). These standards explicitly acknowledge the need for "reasonable and supportable information" that is available without "undue cost or effort," effectively codifying the role of estimates.
• 2024-2025: Implementation and Mandatory Adoption: Major jurisdictions, including the European Union (through the Corporate Sustainability Reporting Directive – CSRD), Australia, and Singapore, have begun the process of integrating these standards into national law, making high-quality reporting a legal requirement for thousands of firms.

This timeline illustrates a shift from "best effort" reporting to a regime where data gaps must be managed through professional judgment and standardized estimation techniques.

Supporting Data: The Scale of the Data Gap

The reliance on estimates is supported by current industry data highlighting the challenges companies face in data collection. According to recent surveys of Chief Financial Officers (CFOs) and sustainability leads:

1. Scope 3 Challenges: A 2023 study found that while nearly 90% of large enterprises have committed to carbon reduction targets, fewer than 25% feel they have "high-quality" data for their Scope 3 emissions—those produced by their suppliers and the end-use of their products.
2. The Supplier Burden: In global manufacturing, a single Tier 1 supplier may have hundreds of sub-suppliers. Estimates suggest that for a typical multinational corporation, over 80% of their environmental impact occurs in the supply chain, where primary data collection is most difficult.
3. Investor Demand: Institutional investors representing over $120 trillion in assets under management have signaled that they prefer "well-explained estimates" over "omitted data." This indicates that the market values directionally correct information for risk assessment more than silence.

These figures underscore the practical reality that if companies were to wait for 100% accurate primary data from every supplier in their value chain, the transition to a low-carbon economy would be significantly delayed.

Building Credibility Through Governance and Transparency

The primary risk associated with the use of estimates is the potential for "greenwashing" or the unintentional misleading of stakeholders. If estimates are applied inconsistently, based on flawed assumptions, or lack proper oversight, they can quickly undermine the credibility of an entire organization. However, professional bodies like the Association of Chartered Certified Accountants (ACCA) argue that estimates themselves are not the problem; rather, poor practice and a lack of transparency are the true threats to trust.

Credibility in the modern reporting era is derived from how an organization handles uncertainty. Those who excel in this area typically exhibit several key behaviors:

• Explicit Disclosure of Assumptions: They clearly state the methodologies used to arrive at an estimate, including the sources of proxy data and the rationale behind specific calculations.
• Robust Internal Controls: They subject sustainability estimates to the same level of internal audit and governance as financial estimates.
• Integration with Financial Systems: Rather than treating sustainability as a siloed "marketing" exercise, they integrate ESG data into the core enterprise resource planning (ERP) systems used by the finance department.
• Iterative Refinement: They acknowledge that estimates are not static. As data quality improves and more suppliers provide primary information, these organizations update their models and restate previous figures where necessary to ensure ongoing accuracy.

Professional Perspectives and Official Responses

The shift toward estimate-based reporting has drawn significant attention from professional accounting and auditing bodies. Aaron Saw, Head of Corporate Reporting Insights – Financial at ACCA, has emphasized that finance professionals are uniquely equipped to lead this transition. In the ACCA report, "Sustainability reporting: working with estimates," it is noted that the principles of "reasonable and supportable assumptions" have long been the bedrock of financial accounting.

"For finance professionals, this is familiar territory," Saw notes. "Assumptions, judgment, control, and transparency have long been central to financial reporting—and those same principles now apply to sustainability reporting."

Standard-setters have also weighed in. The ISSB has built "proportionality mechanisms" into its standards, acknowledging that smaller companies or those in developing economies may need to rely more heavily on estimates and qualitative descriptions as they build their data capabilities. This pragmatic approach is intended to encourage participation and prevent the "perfect" from becoming the enemy of the "good."

Broader Impact and Long-term Implications

The institutionalization of estimates in sustainability reporting has far-reaching implications for the global economy. First, it democratizes the ability to report. By allowing for the use of "reasonable and supportable" estimates, the barrier to entry is lowered for mid-sized companies that lack the massive budgets required for real-time IoT tracking across their entire supply chains.

Second, it shifts the focus of corporate strategy from mere "compliance" to "risk management." When a company uses estimates to identify a potential carbon "hotspot" in its supply chain, it can take preemptive action to mitigate that risk, even if the exact tonnage of CO2 isn’t known to the decimal point. This proactive approach is what investors are truly seeking: evidence that management understands its exposure to climate and social risks.

Furthermore, the use of estimates acts as a "bridge" to a future where high-quality data will be the standard. As more companies use estimates, they create a demand for better primary data, incentivizing suppliers to improve their own reporting capabilities. This creates a virtuous cycle of data improvement.

Conclusion: Leading the Change

Ultimately, the goal of sustainability reporting is not to achieve absolute perfection from the first day of implementation. Instead, it is about providing decision-useful information that explains how an organization manages its exposure to the uncertainties of a changing world. The natural, social, and economic environments are evolving at an unprecedented pace, and the window for effective corporate response is narrowing.

Organizations that choose to wait for perfect data before disclosing their impacts and risks are likely to fall behind their peers, lose favor with investors, and struggle to comply with emerging legal mandates. Conversely, those that act now—utilizing well-governed, transparent, and reasonable estimates—will be better positioned to navigate the complexities of the modern market. By embracing the role of estimates, the global business community can ensure that sustainability reporting remains a powerful tool for accountability and a catalyst for meaningful environmental and social progress. Proactive leadership in this area is no longer just an ethical choice; it is a fundamental requirement for long-term corporate resilience.