The Real Effect of Harmonizing Climate Disclosures: Why Comparable Disclosure Cuts Carbon

A central debate in corporate governance and sustainability standard-setting revolves around the tension between global comparability and local relevance. While international bodies like the International Sustainability Standards Board (ISSB) push for unified, cross-border reporting frameworks, some often worry that one-size-fits-all templates overlook local business realities and create heavy administrative burdens without driving real environmental progress. Does standardizing climate reporting actually push companies to cut emissions, or does it simply produce tidy paperwork? 

In a study with my colleagues Jeong-Bon Kim and Yi-Chun Chen, The Real Effect of Climate Reporting Harmonization on Carbon Emissions, we examined a major turning point in global corporate reporting to see whether establishing a common reporting standard leads to real-world decarbonization. 

To isolate the impact of reporting standards from local regulations or political shifts, we looked at the Carbon Disclosure Project (CDP)—a leading voluntary disclosure platform used by thousands of companies worldwide. In 2018, CDP redesigned its questionnaires to align directly with the four pillars of the Task Force on Climate-related Financial Disclosures (TCFD): governance, strategy, risk management, and metrics and targets. Crucially, this shift was about comparability, not volume. Companies were not suddenly forced to generate massive amounts of new data; instead, fragmented, piecemeal information was reorganized into a standardized format that allowed direct, apples-to-apples comparisons across companies globally. 

Tracking over 14,000 companies across 91 countries between 2015 and 2020, we compared businesses that adopted this standardized format against similar peers in the same industries and countries that did not. The findings show that standardizing climate reporting led to immediate and lasting cuts in direct emissions. Companies using the aligned reporting format reduced their direct operational (Scope 1) emissions by 5.9% in the first year, 7.4% in the second year, and 7.7% by the third year compared to their non-adopting peers. 

A common concern with reported cuts in direct emissions is carbon outsourcing—the suspicion that companies might simply contract out pollution-heavy operations to suppliers so their own footprint looks cleaner. We examined upstream supply chain (Scope 3) emissions and found that they also fell by approximately 3.6%, particularly among businesses whose suppliers were part of the same standardized reporting network. This confirms that the drop in emissions reflected genuine operational improvements throughout the supply chain rather than an accounting illusion. 

Why does a standardized disclosure format compel managers to cut carbon? We identified three primary drivers. 

First, uniform reporting makes peer benchmarking transparent. When companies report the exact same metrics, underperformers can no longer hide behind selective disclosures. The largest emission reductions occurred in highly competitive global industries where peer comparison is most direct. 

Second, disclosure credibility matters across the broader market. While a company having third-party auditors verify its individual emissions numbers did not make much difference on its own, operating in an industry where external audits are standard practice led to significantly larger emission cuts. When investors and peers trust an entire industry’s data, competitive pressure intensifies. 

Third, market discipline drives real change. The emission reductions were strongest in countries with deep, active stock markets. Companies adopting the harmonized framework saw an approximate 36% increase in ownership by distant, climate-focused institutional funds, alongside a 60% to 80% decline in climate-related shareholder resolutions. Instead of relying on contentious boardroom battles or public proxy fights to push for change, global investors used standardized data to direct capital toward cleaner firms and step back from laggards. 

Importantly, cutting emissions did not come at the expense of financial performance. Adopting companies maintained steady profit margins while enjoying higher sales growth (up 1.5 to 1.9 percentage points) and improved return on assets. Far from destroying competitiveness, standardized disclosure helped companies streamline operations and attract international capital. 

As policymakers and executives navigate the rollout of global frameworks like ISSB, the European Union's CSRD, and regional climate rules, our findings provide a clear takeaway for boardrooms. Standardized reporting is far more than compliance overhead; it provides the market visibility required to hold companies accountable and reward operational improvements. For the case of decarbonization, our evidence highlights that cross-border comparability has distinct benefits for reducing emissions by enabling effective peer benchmarking and capital allocation. A shared reporting language does not just measure climate progress—it actively drives it. 

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Aaron Yoon is a Professor in Accounting and Law at HKU Business School, The University of Hong Kong.

This blog is based on a paper presented at the Lisbon Sustainability Week 2026, held at Católica-Lisbon School of Business and Economics and organised with Santander Central Services and ECGI. Visit the event page to explore more conference-related blogs.

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