Why Banks Should Care About Nature Risk in their Loan Books

For banks, the case for addressing nature risk does not ultimately rest on disclosure requirements or sustainability commitments. It rests on a financial proposition: nature degradation can affect borrowers’ cash flows, asset values and creditworthiness.

The analytical challenge is to trace this risk from environmental change, through borrower-level financial performance, into established banking risk categories. That requires moving beyond measures of nature dependency towards an assessment of exposure, vulnerability and financial materiality.

Nature underpins economic activity across a broad range of sectors

Corporate dependence on nature extends well beyond agriculture, forestry and other sectors with obvious links to natural resources.

Businesses rely on ecosystem services including water provision, soil productivity, pollination, flood regulation and erosion control. These dependencies may arise through direct operations, physical assets or upstream supply chains.

ECB research found that 72% of euro-area non-financial companies are highly dependent on at least one ecosystem service. These companies account for approximately 75% of corporate bank lending in the region. Indirect supply-chain dependencies are particularly important, substantially reducing the apparent differences in exposure between countries and sectors.

This does not mean that three-quarters of euro-area lending is at risk of loss. Dependency is a necessary but not sufficient condition for financial risk. Nevertheless, it suggests that nature-related transmission channels potentially sit across a substantial proportion of bank balance sheets.

Nature degradation can affect borrowers’ financial performance

A nature dependency becomes financially relevant when a borrower is exposed to a change in the availability or quality of the ecosystem service on which it relies.

Physical risks can arise from acute shocks, such as drought or flooding, and from chronic changes in water availability, soil productivity or ecosystem condition.

Transition risks arise from changes in policy, regulation, technology, litigation and market expectations. Measures addressing deforestation, pollution, water use or ecosystem conversion can raise costs, require additional investment, constrain production or affect market access.

These risks can affect the principal components of enterprise value and debt-service capacity:

• Revenue, through reduced output, disruption or loss of market access;
• Operating expenditure, through higher input, treatment or compliance costs;
• Capital expenditure, through investment in resilience or remediation;
• Asset values, where productive assets become impaired or stranded; and
• Liabilities, including fines, litigation and restoration costs.

The financial effect depends not only on the borrower’s dependency, but also on its geographic and supply-chain exposure, sensitivity to the shock and ability to adapt.

Banks therefore need to distinguish between four concepts:

• Impacts: the positive or negative effects a borrower has on nature, which may become financially relevant through regulation, litigation or changing market expectations
• Dependency: reliance on an ecosystem service;
• Exposure: contact with a location, activity or supply chain where that service may deteriorate;
• Vulnerability: sensitivity to the shock and capacity to adapt; and
• Financial risk: the resulting effect on cash flow, assets, liabilities and creditworthiness.

Many nature assessments stop at dependency or exposure. Credit analysis needs to progress through all four.

Borrower-level effects transmit into established banking risks

Nature risk is not a separate category alongside credit and concentration risk. It is a driver of those risks.

Weaker revenues, higher costs or asset impairment can increase probability of default. Falling collateral values, remediation liabilities or stranded assets can raise loss given default. These effects may also reduce covenant headroom, constrain refinancing and weaken internal credit ratings before a default occurs.

The transmission pathway is straightforward:

Nature-related shock → borrower financial impact → deterioration in credit quality → potential bank loss

Nature can also create correlated exposures that are difficult to identify through conventional sector analysis. Borrowers across agriculture, food processing, manufacturing, property and hospitality may depend on the same watershed, commodity or ecosystem.

Banks could therefore face concentrations across locations, supply chains, ecosystem services and regulatory changes, even where their portfolios appear diversified by sector.

Aggregate exposure is significant, but it has not yet been translated into expected losses

Early portfolio studies consistently point to widespread nature dependency.

The ECB estimates that 75% of euro-area corporate loan exposures have a strong dependency on at least one ecosystem service. Important dependencies include surface and groundwater provision, flood and storm protection, and erosion control. Vulnerability is concentrated in particular sectors and regions.

At the macroeconomic level, analysis commissioned by the Green Finance Institute found that a combination of domestic and international nature-related shocks could leave UK GDP up to 12% lower than its counterfactual level by the 2030s. This was an adverse scenario, not a forecast, but it illustrates the potential scale of the risk.

These estimates largely measure dependency or exposure, rather than changes in probability of default, loss given default or expected credit loss. They should not be converted mechanically into credit adjustments.

Instead, they demonstrate the need to identify where more granular analysis is warranted.

Conventional credit processes may miss the risk

Nature risk has several characteristics that make it difficult to integrate into conventional credit assessment.

It is highly location-specific. Sector and country data may be insufficient where the risk depends on the condition of a particular watershed or production region.

Material dependencies also frequently sit upstream. Analysis limited to a borrower’s direct assets may miss exposure embedded in commodities and components.

Nature degradation may be non-linear, making historical performance a poor guide to future conditions. Relevant time horizons may also extend beyond the initial loan term, while still affecting refinancing risk, collateral values or the useful life of an asset.

A high dependency score alone does not show whether a borrower can substitute an input, pass costs to customers, relocate production or invest in adaptation. Decision-useful analysis must connect environmental shocks to company-specific financial sensitivity.

Supervisory expectations are developing

The European Banking Authority’s ESG risk management guidelines have applied to most relevant institutions since 11 January 2026. They require banks to identify, measure, manage and monitor ESG risks and treat them as potential drivers of established financial risks. They also call for integration into risk appetite, internal controls and ICAAP.

Methodologies remain less mature than those used for climate risk. But banks do not need to wait for a single standardised model. A pragmatic approach is to screen portfolios for potential concentrations and then apply more granular analysis where the financial stakes warrant it.

From portfolio exposure to credit decisions

The central question is not whether a bank’s loan book depends on nature. Existing evidence suggests that nature dependencies are widespread.

The more useful questions are:

1. Where are material nature risks concentrated?
2. Which borrowers are most vulnerable?
3. How could plausible shocks affect cash flow, collateral and creditworthiness?
4. How should those findings inform underwriting, pricing, limits, monitoring and engagement?

This does not imply withdrawing from every nature-dependent sector. The objective is better differentiation: between dependency and material risk, between resilient and vulnerable borrowers, and between companies with credible adaptation plans and those whose financial resilience rests on natural systems they have not adequately assessed.

For banks, nature risk becomes actionable when it moves beyond a portfolio heatmap and begins to inform financial decisions.