a) Conceptual Considerations – Risk managers are presented with new ideas when evaluating financial risks related to climate change. These ideas play a significant role in determining the extent of exposure to climate risk and measuring the financial risks associated with it.
a1) Physical and transition risk measurement considerations – To measure climate-related financial risks, there are two types of drivers – physical and transition risks. Physical risks are hazards that can be linked to financial exposure using damage functions, which measure the impact of specific hazards on real assets and financial flows. The challenge is finding the empirical functions for all sectors, exposures, and hazards. Transition risks, on the other hand, can be estimated by linking specific transition risk drivers to economic factors that generate financial flows. Due to the interdependent nature of these risks, they may need to be considered together, as actions taken to mitigate physical risks may also increase the probability of transition
risks.
a2) Exposure granularity – Banks and other financial institutions are exposed to climate-related financial risks through their dealings with clients and counterparties. To estimate the impact of climate risk drivers, banks and supervisors must decide on the level of exposure granularity required for their risk assessments. This decision is influenced by factors such as the specific risk drivers, the availability of data, the risk management decision, and computational complexity. The chosen methodology will affect the usefulness of model outputs for risk management, with higher granularity approaches being more useful for underwriting and valuation but suffering from high computational intensity and a lack of standardized data. Conversely, less complex methodologies that tolerate sparse data may be more useful for strategic planning or portfolio allocation. Banks and supervisors face a trade-off in these methodological decisions.
a3) Top-down and bottom-up approaches – Both exposure mapping and risk estimation involve selecting either top-down or bottom-up approaches. Top-down approaches begin with a general or aggregated measure of risk and attribute it to component parts, while bottom-up approaches assess risk at the component level and aggregate it up to provide a consolidated view of risk. Top-down approaches assume that sector or industry averages can be applied to individual exposures, while bottom-up approaches assess relative risk exposure at the asset or counterparty level. The choice of approach should consider potential correlations among risk exposures that could amplify or diversify risk within a portfolio or bank.
a4) Incorporating risk mitigation and risk reduction – Banks assessing climate-related financial risks should estimate the effect of potential risk mitigation and distinguish between net and gross exposures, where net exposure incorporates offsetting strategies and gross exposure does not. Counterparties can also take measures to offset climate-related risks through insurance coverage or other adaptation strategies. Calculating gross
exposure is important to understand the present magnitude of climate-related risks and to account for the potential failure or changes to mitigants. Banks and supervisors should consider measuring the effects of gross risk exposure and mitigants separately to fully understand the costs, benefits, and efficacy of different risk management strategies.
a5) Heterogeneities – Banks must consider their unique climate-related financial risks, which can vary based on their clients’ exposure to geographic regions, markets, sectors, political environments, and technology. This heterogeneity affects the selection of measurement approaches and model types. For example, climate hazards vary regionally, and sectoral classification can mask differences in risk exposure within a sector. National and subnational policy and regulatory regimes also influence risk vulnerability.
a6) Sources of uncertainty – Measuring climate-related financial risks involves uncertainty and assumptions about the interactions among climate, anthropogenic activity, and economic activity, which can lead to misestimation of risks. Estimates of climate sensitivity have generally trended higher, indicating that climate-related financial risks may be underestimated. Historical data is limited in risk estimation or model calibration, and assumptions about the future behaviour of economic actors, policymakers, and technological advancements introduce a high level of uncertainty. Model uncertainty arises from potential non-linearity in impacts, interconnections among natural systems, and spatial heterogeneity. The long time horizons over which these climate impacts are expected to manifest require assumptions about discounting and timing of occurrence. Forward-looking scenarios are often evaluated to take these different drivers of uncertainty into account. Advances in modelling, data, and technical alternatives could help reduce uncertainty, but residual uncertainty may remain even with such advances.
b) Data needs – Assessing climate-related financial risks requires new types of data that may not meet traditional quality standards. Historical data may not be representative of future climate-economy or climate- financial relationships. Three broad data categories needed for risk assessment are:
b1) data describing physical and transition risk drivers, needed to translate climate risk drivers into economic risk factors (i.e. climate-adjusted economic risk factors)
b2) data describing the vulnerability of exposures, linking climate-adjusted economic risk factors to exposures
b3) financial exposure data, needed to translate climate-adjusted economic risk into financial risk
b1) Data describing physical and transition risk drivers – Climate-related risk assessment for banking exposures begins with data on physical and transition risk drivers, including climate and hazard information. Geographical data, cost and performance data for energy substitutes, and other data can be used to estimate energy price relationships, identify at-risk locations, and influence economic outcomes. Many types of climate risk driver data are supplied by government agencies, academic organizations, and commercial third parties.
Off-the-shelf data sets are available to identify areas exposed to individual physical hazards, and several third-party data providers offer climate analytics that calculate aggregate physical risk indices. Climate data may feature in models that generate optimal carbon prices or projections of economic activity, but only some institutions have the expertise and resources to estimate these risk factors in-house, and others may choose to
source them from external third parties.
b2) Data describing the vulnerability of exposures – Banks and supervisors need exposure vulnerability data to assess the impact of climate-adjusted economic risk factors on bank exposures. These data vary depending on the climate risk driver being considered. Physical risks can affect the economy in various ways, and geospatial data are crucial to assess their impact on bank lending exposure. Granular details about a borrower’s value chain and interconnectedness among borrowers may also be necessary to estimate the
potential impairment. Transition risk assessments require data about a corporation’s carbon sensitivity, including GHG emissions, productive capacity, and innovation capabilities. The price elasticity of energy demand and supply constraints are also crucial in assessing the profitability of economic sectors.
b3) Data to translate climate-adjusted economic risk factors into financial risk – Banks and supervisors need additional data to estimate financial loss from exposure vulnerability. They can use financial variables commonly used in risk measurement, such as cash flow projections, valuations, or prices. Portfolio composition and counterparty information are also necessary to estimate potential impacts on exposures and adjust credit valuation and revenue forecasts. To model bank liquidity impacts from climate risk, data on funding provider behaviours (depositors, bondholders, wholesale funds) in response to climate risk drivers are required.
c) Candidate methodologies – The early stage of climate-related financial risk estimation lacks a consensus on preferred modelling approaches. There are various conceptual modelling and risk measurement approaches that can be used for estimation.
c1) Models for assessing economic impacts of climate change – To quantify climate-related financial risks, banks and supervisors must first specify the economic variables underlying asset performance. Various modelling approaches exist, each with strengths and weaknesses related to complexity, validity of assumptions, transparency of mechanisms, data requirements, and computational burden.
Outputs of these models can be used as inputs into stress testing approaches that link future climate paths and economic damages to risk in bank portfolios. However, these models often lack spatial granularity needed to
assess specific risk exposures, and a narrower scenario narrative may be needed for more precise assessments.
c2) Broad risk measurement approaches – Measuring climate-related financial risk is not fundamentally different from standard scenario analyses or stress tests, but uncertainties in impact, time horizon inconsistencies, and limited historical data make it complex and less reliable. Conventional risk measurements can be adapted, but current practices include:
a1) Bank-level methodologies – These include the following:
a2) Supervisor-level methodologies – Supervisors use similar indicators and metrics as banks to assess exposure to climate-related financial risks, based on portfolio, sectoral, or geographical characteristics. They also consider
different sets of indicators for transition and physical risks.
b) Risk quantification: scenario analysis, stress testing and sensitivity analysis –
b1) Bank-level methodologies – Bank-level scenario analysis and stress testing methods may be used to quantify climate-related financial risks or to inform strategic planning. Currently, these tools are mostly focused on credit
risk or market risk analysis. Climate-related financial risk scenario analysis is applied with the goal of understanding the potential impact on selected portfolios, to refine methodologies and assess limitations and benefits. These
exercises are also used to identify counterparties which need to be engaged to support their transition. A crucial objective for banks is the translation of transition and physical risk drivers into financial risks, and in particular
their incorporation into internal models, which still seems challenging.
b2) Supervisor-level methodologies – Supervisors use scenario analysis and stress testing for microprudential supervision and macroprudential policies. For microprudential supervision, they quantify banks’ financial exposures to specific climate risk drivers and assess the vulnerability of banks’ business models. For macroprudential policies, they assess the size and distribution of climate risks in the financial system and whether these risks may be systemic. These analyses primarily focus on credit and market risks from financial institutions’ loan and investment portfolios. However, future applications may extend beyond these areas. Climate scenario analysis and stress testing are exploratory tools used by supervisors to better understand the impact of climate change on banks’ risk management and business strategy, and to raise awareness in the industry about these risks, unlike traditional supervisory stress testing, which aims to determine a bank’s resilience to
financial losses and may inform capital requirements. Different approaches are used to model the impact of climate-related risks at the macro, sector, and firm levels.
b3) Third-party approaches – Supervisors and banks sometimes use third-party methodologies or tools for climate scenario analysis and stress testing. These methodologies typically include exposure mapping, scenario selection, and the assessment of impacts on financial performance. They may provide various risk metrics such as climate value-at-risk, PD of firm, expected shortfall, and expected losses. Some methodologies also consider factors such as vulnerability to climate events, adaptive capacities, and alternative sources of production. Third-party methodologies may use climate risk scores or damage functions to assess physical risks, and can segment or aggregate exposures by type of loan, sector, or hazard.
a) Limitations of observed risk classification approaches –
The goal of risk classification is to group exposures based on criteria that reflect their risks. Publicly available information, such as air emissions accounts and vulnerability indices, can be used to identify sectors and countries sensitive to climate change. This can help banks monitor concentration risk and inform strategic planning and portfolio allocation. However, aggregate risk classification approaches have limitations, as identification criteria may not be granular enough to differentiate among counterparties. For example, some approaches assume that counterparties from the same geographical location share similar risk characteristics. However, the reality is that transition and adaptation capabilities of counterparties may vary depending on the specific physical or transition
risk driver under scrutiny. Moreover, an individual counterparty’s sensitivity to climate-related risks may not necessarily align with a transition-sensitive sector or geographical area. Additionally, without the ability to clearly identify and measure the hedging strategies employed by counterparties, it could be challenging to differentiate between gross and net exposure. Banks can complement these approaches by assigning a rating or score, but this is challenging due to issues with data availability and quality and the lack of an established link between climate-related information and financial risk parameters. Therefore, ratings are often considered separately from banks’
financial risk scoring.
b) Risk differentiation and comparability across banks and jurisdictions –
Risk classification systems aim to achieve comparability, but this objective has its drawbacks. Standardization and simplification elements are introduced to enable comparisons between banks’ exposures within or across jurisdictions, which can lead to a reduction in risk differentiation. A balance is needed between granularity/complexity and comparability. Obstacles to developing common standards include differences in risk profiles across jurisdictions and aggregation issues for large international banks. Local conditions may conflict with group-wide policies for climate risk assessments, and IT requirements for large climate databases may exacerbate existing deficiencies in risk data aggregation and reporting noted by supervisors.
c) Challenges in the availability of appropriate data –
Limited data and information availability hinder the development of climate risk measurement processes. External data providers may alleviate some of these limitations, but concerted efforts by banks and supervisors are likely necessary to overcome these challenges. This obstacle has been identified as a major impediment in recent years, and this observation has been confirmed by industry outreach seminars and a supervisory survey.
d) Data describing physical and transition risk drivers –
Climate data may be insufficient or not updated consistently with standard financial risk measurement frequencies, presenting methodological challenges. Climate model information may be presented in aggregated form, which may not accurately reflect the economic and financial impact analysis required for higher granularity. Moreover, the quality and availability of climate-related data may vary among jurisdictions, which may impede the implementation of comprehensive analyses.
e) Data describing the vulnerability of exposures –
e) Challenges in designing a modelling framework to capture climate-related financial risks –
a. Uncertainty around climate risk drivers – Multiple uncertainties surround both transition and physical risk drivers, especially related to non-linear aspects of the climate system. There could be many combinations of transition drivers leading to the same CO2 concentration outcome, resulting in significant variance in economic and financial impact across and within sectors and geographies. Given this, accounting for uncertainty through alternative scenarios and different modelling approaches is necessary to make the analysis more robust. However, exploring multiple scenarios may be resource-intensive.
b. Capturing the specific impacts of climate scenarios – There is a need to develop modeling frameworks that can capture the impacts of climate scenarios, including stressed variants. However, currently available methodologies are not fully integrated or tractable, and banks and supervisors are using existing tools based on their relative strengths. Macroeconometric models are used to adjust for the macroeconomic impact of carbon price shocks when assessing transition risk, but they may not adequately capture climate scenario dynamics. Existing models that estimate
economic impacts from climate change usually do not capture the full range of potential climate change impacts, such as extreme weather events or potential future disruptive changes in climate.
c. Comprehensiveness of modelled impacts – Modeling challenges exist in capturing the impact of climate scenarios with a chosen risk classification and granularity. For physical risk, the lack of damage functions at the granular geographic level makes translating physical risk drivers into expected losses difficult. The assessment should also model second-round effects like the
propagation of policy or physical risk shocks and the adaptive and mitigation abilities of economic agents. Additionally, assessing the market power of individual firms to pass on carbon price increases to consumers and evolving insurance coverage or governments’ natural catastrophe schemes are also critical information to consider.
Supervisors may develop multiple models to address the complexities of climate-related risks. Some have added production network modules to macroeconometric models to capture sector-level transition impacts of carbon price shocks. However, connecting these disparate models with different theoretical foundations would require additional research.
2. Translating scenario outputs to financial risks – Financial models used to assess credit risk rely on historical statistical relationships between risk drivers and parameters such as PDs or LGDs. However, historical observations of climate-related risks are not good predictors for future patterns, making it challenging for financial models to derive empirical risk parameters. To address this, some banks and supervisors attempt to attribute the impact of stressed scenario variables on counterparties based on characteristics such as CO2 emissions, then infer the impact on risk parameters. However, this approach has limitations, including data availability challenges and simplified assumptions about the relationship between variables and financial impact.
3. Time horizon related challenges – Banks and supervisors face challenges in considering longer time horizons when assessing climate-related risks. These horizons can extend up to 2050, leading to increased uncertainty in economic and financial projections, as well as limitations in modelling. Banks may struggle to internalize negative feedback loops from their lending decisions due to risk frameworks geared towards short-term exposures. Reflecting on existing measurement approaches and potentially leveraging best practices in modelling approaches may help address these challenges. However, there is a need to evaluate the appropriateness of individual supervisory tools for various time horizons. Results of climate-related scenario exercises may challenge the traditional use of scenario analysis in stress testing, instead informing the strategic and business model resilience of institutions.
4. Operational complexity in the measurement of risk – The TFCR industry outreach and supervisory stocktake suggest that banks and supervisors need to continue building operational capabilities to assess climate-related risks. This is a difficult task that requires significant resources, including adequate systems infrastructure, relevant human resources, and a sophisticated organization. A bank’s ability to assess its overall exposure to climate risks will heavily rely on the quality of its IT systems and its ability to manage large amounts of data. Climate risk measurement also requires interdisciplinary expertise and may require more sophisticated modelling techniques for complex banking groups.