Executive summary

Since the adoption of the Business Responsibility and Sustainability Reporting (BRSR) framework in 2022–23, environmental reporting has shifted from being a peripheral sustainability exercise to becoming a major component of corporate accountability. Investors, regulatory bodies, lenders, customers, and civil society now evaluate firms based on their environmental management and sustainability disclosures, not just their financial performance. Under the BRSR, 1,000 of India's leading firms by market capitalisation are required to report emissions of criteria air pollutants. These include particulate matter (PM), sulphur dioxide (SO₂ ), nitrogen oxides (NOx ), and greenhouse gases (GHGs). The framework recognises that corporate environmental performance extends beyond the contribution of firms to global warming and includes local pollutants. It includes local pollutants that affect public health and ecological conditions. The BRSR is one of the very few sustainability disclosure regimes that mention air pollution as part of ESG disclosures. In 2023, SEBI also introduced BRSR Core, a subset of key performance indicators requiring independent thirdparty assurance, rather than self-disclosure alone.

However, on reviewing the first three years of disclosures under the BRSR framework, we found a significant imbalance between GHG emissions reporting and criteria air pollutant reporting. While GHG emissions reporting has gained traction and become more consistent, standardised, and investor-oriented, criteria air pollutant reporting remains scattered and incomplete. This has significant on-the-ground implications, as air pollution poses one of the most pressing environmental risks for companies, impacting public health, regulation, business continuity, and reputation. It is estimated that air pollution imposes an annual cost burden of almost USD 95 billion (~INR 9 lakh crore) in India – equivalent to 3 per cent of the country’s GDP (Dalberg Advisors, CII, and Clean Air Fund 2021). While some regulatory measures have been introduced to improve air quality, this aspect is not adequately addressed in disclosures or incorporated into valuations or investment decisions.

In this study, we propose recommendations to transform the BRSR framework from a disclosure mechanism into a system that produces decision-useful information to inform regulation, investment, and corporate action. We intend to strengthen corporate air emissions reporting, making it a financially material metric in investment and financing decisions. At present, air pollutant data remains inconsistently disclosed, rarely thirdparty verified, and seldom incorporated into capital allocation decision-making despite its significant implications for regulatory compliance, operational resilience, and environmental risk. By improving the quality, consistency, and credibility of air pollutant disclosures, we aim to make air emissions reporting a meaningful market signal that can guide regulatory oversight, inform investor decision-making, and mobilise greater corporate and private capital towards air quality management and emissions reduction. More transparent disclosures are therefore not an end in themselves, but a means to direct finance towards cleaner industrial practices and measurable improvements in air quality.

To achieve this, we address two questions that are fundamental to making air emissions performance relevant to regulatory and financial decision-making:

• Can the disclosure gap be closed? We examine whether the lack of data on air pollutants reflects an inherent limitation in sustainability reporting or a remediable design gap. By benchmarking the BRSR against leading global disclosure frameworks, we identify how international practice has incorporated air pollutant reporting and suggest reforms that India can adopt.
• Is the current BRSR data decision-useful? We assess the completeness, consistency, comparability, and reliability of air pollutant data across all BRSR filers to determine whether it is adequate for regulatory oversight and investment analysis. We then identify the specific reporting deficiencies that must be addressed for air performance to become a credible basis for effective sustainability reporting.

Our research focuses on air emissions disclosures rather than on measuring emissions levels. We chose BRSR as our primary dataset because they constitute the mandatory corporate reporting framework for listed companies in India. Our objective is to assess the coverage, consistency, comparability, and decision usefulness of the air emissions disclosures in these reports. Although datasets such as those produced by continuous emissions monitoring systems (CEMS) are very useful in assessing emissions and measuring compliance, they do not provide any information about air emissions disclosure practices, reporting quality, or the treatment of air pollutants within ESG reporting.

Methodology

Our analysis proceeds in two parts:

• A structured global review of eight leading global environmental, social, and governance (ESG) frameworks and regulations: the European Sustainability Reporting Standards (ESRS) and Corporate Sustainability Reporting Directive (CSRD); Global Reporting Initiative (GRI); International Sustainability Standards Board (ISSB); Sustainability Accounting Standards Board (SASB); Integrated Reporting Framework (IRF); Climate Disclosure Standards Board (CDSB); Principles for Responsible Investment (PRI); and the Invest Europe ESG Guidelines. We scored each of these frameworks on eight dimensions of disclosure quality, applied separately to GHGs and air pollutants.
• An Indian BRSR review that analysed all BRSR submissions filed in a standardised, machine-readable format known as XBRL, with the National Stock Exchange (NSE). The empirical dataset covers 1,258 companies tracked over three years, starting with the financial year (FY) 2022–23. For each company-year, we flagged whether the firm had disclosed any air pollutants or GHGs, and whether the data was externally assured. We then built a consistent panel dataset of firms reporting PM, SO₂, and NOx in comparable, mass-based units to test data quality and emissions trends over time.

Figure ES1. Two complementary analyses: A global framework review and a full-population BRSR analysis

Key findings

From the global review

Modern sustainability reporting was introduced as a solution to the dual problem of climate change and industrial energy consumption. With growing scientific evidence linking the increase in GHGs to global warming, stakeholders in finance and regulation realised the need for effective methods for measuring and reporting on the associated risks. In response, innovative frameworks such as the Global Reporting Initiative (GRI) and the Carbon Disclosure Project (CDP) were developed in 1997 and 2000, respectively, forming the basis for modern sustainability reporting. Today, many frameworks (ISSB, SASB, and many more) continue to build on this foundation.

Consequently, climate change discourse around GHGs dominated sustainability reporting, while the impact of other air pollutants remained largely underexamined. Our review of eight leading global disclosure frameworks reveals that only two frameworks, the ESRS and SASB, require standardised and comparable disclosure of data on specific air pollutants. In most other cases, reporting on PM, SO2 , NOx , and other harmful pollutants is left to the discretion of firms, making it voluntary, fragmented, or absent altogether. Consequently, there is inadequate information on most companies’ air-quality risks and their local environmental impacts.

From the BRSR filings

By mandating the reporting of multiple air pollutants, requiring disclosures be submitted in a machine-readable XBRL format, and generating three consecutive years of company-level data, the BRSR has created a corporate air emissions disclosure system and offers a unique opportunity to improve corporate accountability for clean air.

We analysed firms’ BRSR filings through the lens of four interrelated questions:

• How many firms disclose air pollutant data, and how has this evolved from FY 2022–23 to FY 2025–26?
• How do disclosure rates and data quality vary across sectors?
• What structural features of the current BRSR framework limit its utility for air quality governance?
• What targeted reforms would transform BRSR disclosures from compliance reports to genuine policy instruments?

Our analysis yields the following five key findings.

• A widening air–GHG disclosure gap
  The air–GHG disclosure gap is large and gradually widening. In FY 2022–23, about 99.8 per cent of companies (BRSR filers) disclosed GHG data, while only 90.4 per cent reported any air pollutant data – a gap of roughly 9 percentage points. In the study period, this gap widened, from about 9 percentage points in FY 2022–23 to nearly 17 percentage points in FY 2024–25 (Figure ES2). Usually, the same combustion processes generate both carbon and air pollutants, yet companies report the former far more consistently than the latter.

Figure ES2. The air–GHG disclosure gap has widened across three years of BRSR reporting

We found that of the 1,222 companies that filed BRSR in 2024–25, 823 disclosed both air pollutant and GHG data, 247 disclosed GHG, but no air pollutant data, 111 disclosed neither, and just 41 disclosed air pollutant data without any accompanying GHG figures.

Figure ES3. Nearly 1 in 5 firms stops at GHG reporting, skipping air pollutants entirely

• Reporting gaps vary by sector—and not all are equally concerning
  The sectoral analysis shows that the reporting gap varies with the sector’s physical footprint. For instance, about 81 per cent of financial and insurance companies disclose GHGs, but only 10 per cent disclose air pollutants. This is defensible, since their operations produce minimal direct air pollutants. But the same cannot be said of the construction and real estate sectors. Only about 68 per cent of firms in these sectors disclose air pollutant data, compared with 81 per cent that report on GHGs, even though their field sites are among the most visible sources of PM and NOx . Manufacturing firms–which have the greatest potential for air pollutant emissions–report air pollutants and GHGs at nearly equal levels (around 91 per cent). Beyond manufacturing, however, air pollutant disclosure rates fall well below GHG reporting rates across most sectors. This divergence suggests that air pollutant reporting is yet to become as embedded in corporate disclosure practices as carbon reporting, despite being subject to the same reporting requirements (Figure ES3).

Figure ES4. Air pollutant disclosures lag behind GHG disclosures in almost every sector (FY 2024–25)

• Inconsistent units and unexplained zeros undermine data usability
  Unit fragmentation and zero values make air pollutant data impossible to aggregate. Even where companies disclose emissions, they use a wide range of incompatible units. PM alone is reported in more than a dozen different units, including tonnes (t), kilograms (kg), milligrams per normal cubic metre (mg/Nm3 ), micrograms per normal cubic metre (µg/Nm3 ), and parts per million (ppm). These metrics measure fundamentally different quantities–total pollutant load and stack concentration–and cannot be meaningfully added together. About 4 per cent of companies reported a value of zero for PM, SO2 , or NOx , a figure that is difficult to interpret, since the BRSR does not require firms to specify whether a zero reflects genuinely negligible emissions or simply the absence of measurement. Without this distinction, it is impossible to tell whether these companies have no meaningful air pollutant footprint or have not measured it at all, which undermines confidence in the reported data. Of the 681 manufacturing firms that filed BRSR disclosures in FY 2024–25, around 620 reported air emissions. However, only about 240 disclosed PM, SO2 , and NOx levels consistently in tonnes. Unlike GHG emissions, which are reported in a common unit (tCO2 e) and can therefore be consolidated into sectoral estimates, air pollutant data lacks the standardisation needed for comparable analysis. As a result, while manufacturing firms reported a credible cumulative GHG footprint of roughly 776 million tonnes of carbon dioxide equivalent in FY 2024–25, no similarly robust estimate could be derived for PM, SO2 , or NOx emissions.
• Where data is comparable, air pollutant levels are not improving
  Where emissions are reported in a comparable unit, they are not substantially improving. Using a consistent panel dataset of companies with at least two years of comparable data, we find that, for PM, 47 per cent of BRSR filers show a falling trend, indicating improvement, while 44 per cent show a rising trend, indicating worsening in the PM levels. For SO2 , 47 per cent show an improving trend and 46 per cent show a worsening trend. For NOx , more companies are worsening (51 per cent) than improving (42 per cent); similarly, for GHGs, 53 per cent show a worsening trend against 39 per cent showing an improving trend (Figure ES4).

Figure ES5. Nearly half of the firms reported improvement in the air emissions

• Disclosures remain disconnected from independent regulatory monitoring
  The data is disconnected from regulatory monitoring that could validate it. CEMS already transmit real-time, verified emissions data from the most polluting industrial facilities to pollution-control authorities, such as the CPCB. However, this independent baseline is rarely linked to BRSR disclosures. The two regulatory systems operate in parallel rather than in concert. For instance, during our stakeholder consultation, we found that the problem is not in the collection of data but its interpretation and in the coordination of SEBI and CPCB.

Recommendations

To fully leverage the BRSR’s potential as a tool to improve air quality, action is needed from three sets of actors: regulators who set the rules, companies that generate and manage emissions, and investors who can create demand for better performance through capital allocation. To move the BRSR from a framework that merely collects air pollutant data to one that generates credible, comparable, and decision-useful information, we recommend the following actor-specific interventions.

Regulators (SEBI, along with the Ministry of Environment, Forest and Climate Change [MoEF&CC] and CPCB) should:

• Issue a technical guidance document for BRSR disclosures that standardises pollutants, units, and measurement methods. It should specify, for each relevant sector, the mandatory pollutants to be reported, mass-based reporting units (tonnes per year), reporting boundaries, and permitted measurement and estimation methods, including for volatile organic compounds and hazardous air pollutants, which are mandatory to report yet are almost entirely unreported. Crucially, in addition to mandating a unit, a free, sectorspecific conversion methodology must be provided, since standardising a unit without supplying the method simply perpetuates the existing inconsistency.
• Require zero values to be explained. Any company reporting nil PM, SO2 , or NOx emissions should be required to explain whether its activities genuinely generate no emissions or whether the value reflects the absence of measurement, thereby separating credible zeros from placeholders.
• Bring PM, SO2 , and NOx into the BRSR Core, with mandatory third-party assurance. Air pollutant data should be subject to the same level of assurance as carbon, energy, and water, beginning with the largest listed companies and the most polluting industries. The assurance process should check methodological consistency, the completeness of pollutant coverage and boundaries, and the transparency of assumptions.
• Cross-validate BRSR data against CEMS data. A formal data-sharing mechanism among SEBI, MoEF&CC, and CPCB would enable BRSR filings to be compared with an independent baseline, exposing implausible entries and making the BRSR an integral part of national air quality governance.
• Move to a sector-specific disclosure framework. SEBI should define sector-wise frameworks for air pollutant disclosures rather than relying on company size alone, so that firms whose operations generate significant emissions must report them regardless of an umbrella framework that does not require all sectors to report air pollutants.

Every companies have their GHG reduction targets and this is because GHG is prioritised globally because og climate change and global warming potential. However, air pollution has a regional impact. It not only impacts the health, but gradually deteriorating Air quality leads to GRAP like measures which impacts business. It is self regulatory action and this can be done by treating air emission in the same way like GHG, such as making emission reduction targets, shifting to cleaner fuel, and accounting their supply chain emissions.

Financial risk is the major influence for the companies. Investors must consider that the companies or the companies having heavy emitter supply chain is always at risk of regulatory compliance. This should be considered other than only looking at GHG emissions. measure, disclose, and reduce their emissions.

India’s sustainability disclosure regime is at a turning point. Three years of mandatory BRSR filing have already produced a longitudinal dataset. The extension of the BRSR Core to the top 1,000 companies by FY 2026–27, the phasing-in of value-chain disclosures, and closer cooperation between SEBI and environmental regulators can together create an opportunity for greater institutional alignment to improve air quality. SEBI has already shown, through its GHG guidance note and the BRSR Core, that it can convert a difficult environmental requirement into a workable one. Applying the same principles to air pollutants by framing guidelines on units and measurement as well as adding PM, SO2 , and NOx to the BRSR Core can transform the BRSR from a world-leading disclosure mandate to a powerful instrument for cleaner air.

This study is limited to the listed companies within the BRSR mandate and to PM, SO₂, and NOx . Future research can deepen the findings on standardised, sector-specific reporting protocols and unit-conversion methodologies, and eventually integrate industrial CEMS data with BRSR disclosures.