Why Green Asset Ratio Matters More Than Most Banks Think

The Green Asset Ratio, or GAR, is often introduced as a disclosure metric. That description is technically correct, but strategically incomplete.

In practice, GAR is becoming something much more important. It is a visible indicator of how successfully a bank is translating sustainability ambition into balance-sheet reality. It signals whether green finance is still mostly a product narrative, or whether it is beginning to reshape credit allocation, portfolio construction, data architecture and client strategy.

That is why GAR deserves more attention than a narrow compliance reading would suggest.

Across Europe, the Green Asset Ratio emerged from Article 8 of the EU Taxonomy framework as a way to show what share of a bank’s covered balance sheet is actually financing taxonomy-aligned economic activities. In simple terms, it asks a difficult but powerful question: of the assets a bank holds, how much can genuinely be evidenced as environmentally sustainable under a rules-based framework? The European Banking Authority embedded GAR and its companion metric, BTAR, into Pillar 3 ESG disclosures to improve comparability and make sustainability-related banking exposures more visible to markets. 

Türkiye has entered this conversation in a much more structured way. According to the BRSA framework the Green Asset Ratio is no longer just a European banking concept being observed from a distance. It has become a domestic reporting and portfolio classification issue for Turkish banks as well. The BRSA regulation published on 11 April 2025 introduced a measurable framework for the banking sector to identify, classify and report green assets, with first reporting required from 30 June 2025.     

What makes GAR strategically important is not the formula itself. On paper, it is straightforward. In the Turkish BRSA guide, the ratio is defined as aligned assets divided by eligible assets, with aligned assets meaning exposures that satisfy technical screening criteria, do no significant harm to other environmental objectives and also meet minimum social safeguards.  In the EU context, the logic is similar even if the reporting perimeter and denominator construction differ. The complexity lies not in arithmetic, but in evidence.

That is the real story of GAR.

A green asset is not simply an exposure that “sounds green.” A solar project is not automatically aligned. An energy-efficient mortgage is not automatically eligible for recognition. A transport investment is not automatically sustainable because it sits in a broadly favourable sector. The entire architecture depends on disciplined classification, documentary support and traceable judgement. The implementation captures this clearly by distinguishing between “eligible” and “aligned” assets: an asset may sit within a taxonomy-covered activity, but still fail alignment if DNSH or minimum safeguard conditions cannot be demonstrated. 

This distinction is more than technical language. It is where many banks will either succeed or struggle.

Eligible assets are the starting universe. They are the exposures linked to activities that fall within the technical screening perimeter. Aligned assets are a much narrower subset. They must make a substantial contribution to one or more environmental objectives, avoid significant harm to others, and satisfy social and governance safeguards. That means GAR is not a simple green lending ratio. It is an evidence-based alignment ratio. The difference is profound. A bank may finance many activities that are directionally positive for the transition, but if the underlying files, certificates, impact assessments, policy checks or client-level verifications are incomplete, those assets may still fail to count.   

This is also why many early GAR results in Europe looked so low.

Your draft correctly points to one of the most widely debated structural issues: the asymmetry around SMEs and non-EU counterparties. In the EU model, large institutions’ GAR calculations have historically been pulled down because some exposures influenced the denominator while remaining very difficult or impossible to recognise in the numerator without formal taxonomy disclosures from counterparties. That issue became one of the main drivers behind the 2025 Omnibus simplification debate and the subsequent July 2025 delegated act changes, which aimed in part to reduce denominator distortions and simplify implementation. The European Commission’s February 2025 simplification package explicitly said the GAR revision would address the difference in scope between numerator and denominator, and the 2025 delegated act introduced additional simplifications, including treatment of non-material exposures. 

That matters for two reasons.

First, it confirms that even in the EU, GAR should not be interpreted lazily. A low ratio may reflect genuine strategic weakness, but it may also reflect product mix, client segmentation or reporting perimeter asymmetries. Second, it shows that GAR is not a static metric. It is part of a still-maturing regulatory architecture. This is important for Turkish banks as they build their internal logic. A mechanically compliant calculation may satisfy near-term reporting needs, but a strategically designed GAR programme should be built with enough flexibility to accommodate future taxonomy revisions, expanded disclosure expectations and methodology refinement.  

The banks that will manage GAR well are therefore unlikely to be the ones that treat it as a reporting annex. They will be the ones that treat it as a portfolio management discipline.

That requires several things to happen at once.

The first is asset-level inventory discipline. The BRSA guidance is very clear that banks need a full balance-sheet mapping exercise, excluding certain categories such as central bank claims, central government exposures, multilateral development bank exposures and trading book items before determining the eligible and aligned universe.   If a bank does not know exactly what it holds, under which activity classification, with which documents and under which client structure, its GAR exercise will quickly become manual, inconsistent and hard to defend.

The second is classification logic. NACE mapping and activity-level taxonomy interpretation are not clerical tasks. They shape the entire eligible universe.

The third is documentary strength. Technical screening criteria must be evidenced through real documents, not assumptions. Energy performance certificates, engineering reports, emissions data, third-party environmental certifications and feasibility studies are not supporting details. They are the backbone of GAR defensibility. The same is true for DNSH (Do No Significant Harm).

That is a crucial point. Many institutions still think of green asset identification as primarily a climate exercise. It is not. A bank cannot classify an asset as aligned merely because it contributes to mitigation if the same activity creates material biodiversity harm, water stress, pollution risk or governance failure. GAR is demanding precisely because it is intended to force more holistic judgement.

The fourth requirement is minimum safeguards and governance screening. This is where many sustainability discussions become too narrow. GAR is not only about environmental contribution. In both EU taxonomy logic and the Turkish BRSA structure, alignment also depends on minimum social safeguards.

The fifth requirement is systems architecture. This may ultimately be the most underestimated factor of all. GAR cannot be scaled through spreadsheets for long. It requires a data model that links loan systems, customer information, sector classification, documentation repositories, sustainability data fields and reporting outputs.

This is where GAR becomes strategically valuable even beyond the metric itself.

A bank that builds a robust GAR data architecture is not only preparing for one disclosure. It is laying the groundwork for a much wider sustainable finance operating model.    

That is why the most forward-looking institutions should not ask, “How do we calculate GAR?” The better question is, “What does GAR reveal about the maturity of our sustainable finance infrastructure?”

Because GAR will reveal a great deal.

It will reveal whether green finance sits mainly in presentation decks or actually in the book. It will reveal whether a bank’s product architecture is capable of generating aligned exposures, or only broad green narratives. It will reveal whether sustainability, credit, risk, compliance and technology teams can operate through a common logic. And it will reveal whether the institution has a sufficiently disciplined evidence framework to withstand supervisory, investor and external scrutiny.

This is particularly relevant at a time when the European framework itself is evolving. The EBA’s February 2026 ESG dashboard update noted that taxonomy-alignment charts had not been updated beyond Q4 2024 following the August 2025 no-action letter, reflecting ongoing transition in the reporting architecture.   In other words, the market is still learning. But that should not be misread as a reason to wait. If anything, it is the opposite. The banks that invest early in methodology, controls and data discipline will be far better positioned when GAR becomes more stable, more comparable and more visible in market practice.

For Turkish banks, this is especially important because the BRSA framework arrives at a moment when sustainable finance is moving from thematic relevance to supervisory relevance. Once a measurable ratio exists, it begins to influence management conversations differently. Ratios can be benchmarked. Ratios can be trend-tracked. Ratios can eventually shape appetite, incentives and reputational standing.

Seen this way, GAR is not the end of a sustainable finance discussion. It is the start of a more serious one.

It forces banks to confront a set of difficult but overdue questions. Which parts of the existing book are actually capable of becoming aligned? Which products can generate credible aligned growth? Where are the biggest documentary bottlenecks? Which clients sit closest to taxonomy alignment if the bank actively supports their transition? Which exposures are green in business substance but invisible under current eligibility constraints? And where do the bank’s own systems still rely too heavily on manual judgement instead of structured evidence?

Those are not disclosure questions. They are strategic banking questions.

The institutions that answer them well will not merely report a ratio. They will begin to build a more durable sustainable finance franchise.

In the years ahead, Green Asset Ratio disclosure will undoubtedly continue to evolve. Definitions will be clarified, templates will be amended and taxonomies will mature. But the underlying direction is already clear. Sustainable finance is moving away from broad thematic claims and toward measurable, documentable, portfolio-level accountability.

That shift is not a burden to be managed at the margin.

It is an opportunity to build a bank that is better structured for the transition economy.