Climate risk disclosure has evolved from a compliance-driven reporting exercise to a core component of financial risk management and corporate governance. This evolution reflects a broader recognition that climate risk carries direct and measurable financial risks affecting company valuations, asset performance, supply chain resilience, and the way investors assess and price risks.
As these financial implications become more pronounced, the evolution from voluntary disclosure to mandatory disclosure and assurance signifies a clear reality that climate-related risks are financial risks and must be treated accordingly within financial statements and corporate reporting frameworks. As a result, regulators, investors, and lenders are no longer satisfied with narrative disclosures alone; they increasingly require climate information that is decision-useful, verifiable, and subject to audit-level scrutiny.
Climate change directly affects financial performance, company valuation, and long-term financial stability through both physical risks and transition risks.
Physical Risks
Physical risks arise from climate-related hazards such as floods, droughts, wildfires, and rising sea levels. These risks affect assets, supply chains, and operational continuity.
Transition Risk
Transition risks stem from the global shift toward a low-carbon economy, including regulatory changes, technological shifts, market preferences, and evolving reputational expectations.
Financial impacts are measurable: climate risk can affect revenue, cost of capital, creditworthiness, and ultimately, enterprise value.
Investor scrutiny of climate risk has risen sharply, driven by fiduciary responsibility, stakeholder expectations, and capital market integration. Institutional investors, including pension funds, sovereign wealth funds, and asset managers, now recognise that climate exposure directly affects long-term financial performance and, by extension, their fiduciary obligations.
The Principles for Responsible Investment (PRI)continues to report annual growth in signatories and assets under management committed to ESG integration, reflecting the scale at which climate considerations are being embedded into investment decision-making.
Beyond investors, broader stakeholder expectations are reinforcing this pressure. Customers increasingly favour brands that demonstrate credible climate commitment and leadership. Employees expect corporate responsibility and operational resilience in the face of climate-related disruptions. At the same time, regulators are strengthening non-financial reporting obligations through emerging sustainability disclosure standards such as the International Sustainability Standards Board’s IFRS S1 and S2, signalling that climate transparency is becoming embedded within mainstream reporting requirements.
Capital markets have responded accordingly. Market indices and credit rating agencies now incorporate climate metrics into valuation models and risk assessments. For example, MSCI and S&P Global integrate climate risk analytics into ESG scoring methodologies, while Moody’s and S&P Global Ratingsconsider climate exposure in creditworthiness assessments where financially material.
This broader market-wide change has shifted climate reporting from an optional sustainability exercise to investment-grade disclosure that directly informs capital allocation and risk pricing decisions, thereby necessitating credible, independently assured information.
Climate disclosure alone is insufficient. Like financial accounts, climate disclosures require independent assurance to ensure credibility, accuracy and comparability.
Why Assurance Matters
Despite significant progress in embedding climate risk into financial reporting, several structural challenges threaten the reliability, comparability, and assurance-readiness of climate disclosures. Addressing these constraints is essential if climate reporting is to achieve the same level of rigour and trust as traditional financial information.
One of the most pressing challenges concerns data quality and comparability. Climate disclosure, especially greenhouse gas accounting, depends on complex inputs that are still maturing in consistency and reliability. Scope 3 emissions, which cover indirect emissions across the value chain, frequently rely on supplier data, industry averages, or estimation models that vary widely in methodology and integrity. These variations can result in materially different reported emissions profiles for companies operating in similar sectors. Without robust internal data governance and transparent calculation assumptions, comparability across firms remains weak, undermining stakeholder confidence and complicating assurance engagements.
To address this, organisations must implement strong data governance frameworks akin to those governing financial reporting. This includes establishing documented controls over climate-related data collection and calculation; deploying digital systems that enable audit trails for key metrics; engaging suppliers to improve upstream data quality; and adopting standardised measurement protocols such as the Greenhouse Gas Protocol. Transparent disclosure of assumptions, boundaries, and estimation techniques is essential to achieving audit readiness and reducing the risk of material misstatement.
Another significant challenge is the multitude of standards and the need for harmonisation. The various layers of reporting frameworks, such as the International Sustainability Standards Board (ISSB), the Global Reporting Initiative (GRI), and the Corporate Sustainability Reporting Directive (CSRD) reflects important momentum toward structured climate disclosure. However, differing materiality concepts, overlapping requirements, and jurisdiction-specific obligations can create duplication, inefficiencies, and interpretative uncertainty for multinational organisations. This complexity not only increases compliance costs but also heightens the risk of inconsistent disclosures that are difficult to ensure reliably.
Addressing this challenge requires a strategic and harmonised reporting architecture. Organisations can base their internal reporting frameworks on a globally recognised baseline standard and systematically align with other regulatory and framework requirements. Collaboration across finance, risk, sustainability, and legal functions can ensure consistent materiality assessments and reporting boundaries. Early engagement with regulators and assurance providers further clarifies expectations and smooths the path toward assured disclosures.
A third challenge lies in assurance capacity and technical expertise. As climate disclosures become mandatory and subject to assurance, demand for qualified professionals is outpacing the current supply. The assurance of climate disclosures requires specialised understanding of emissions accounting, scenario analysis, and climate modelling capabilities that extend beyond traditional financial audit expertise. Many organisations are still developing internal capabilities for generating audit-ready climate data, and assurance firms are scaling their technical talent to meet demand, particularly in emerging markets where regulatory requirements may outstrip institutional readiness.
Bridging this gap requires strategic investments from both reporting entities and assurance providers. Reporting organisations must build cross-disciplinary teamsthat integrate finance, risk management, sustainability, and data analytics. Training and capacity building within internal audit and finance functions enhances control environments and facilitates smoother external assurance.
Ultimately, the credibility of climate disclosure depends not only on regulatory mandates but on institutional capability. Robust data systems, harmonised reporting practices, and strengthened assurance expertise are foundational to ensuring that climate disclosures achieve the integrity, comparability, and investor confidence they now demand.
The trajectory from voluntary to mandatory and assured climate disclosure reflects an evolving landscape. Climate risk is increasingly becoming financial risk, with concrete implications for valuation, capital allocation, and corporate resilience. Investors and stakeholders now demand transparent, credible, and verifiable climate data that can stand up to audit scrutiny. Organisations that rise to this challenge by integrating climate risk into financial reporting and ensuring its quality through assurance will not only meet regulatory and investor expectations but also strengthen their competitive advantage in a rapidly transforming global economy.
Written by: Sunday Ojo| Assistant Manager, ESG Advisory Services
Harley Reed (Nigeria)
