IMF Study Finds Japan’s Green Transition Manageable but Uneven Across Industries

The IMF’s ENV-FIBA model integrates macroeconomic and financial simulations to analyze how climate policies and physical risks impact firms, banks, and entire economies. Applied to Japan, it shows that while overall financial effects of decarbonization are modest, sectoral and regional disparities are significant.

The International Monetary Fund’s Monetary and Capital Markets Department, in collaboration with researchers from Bryant University and other partner institutions, has unveiled a groundbreaking analytical tool that links climate science, macroeconomics, and finance. The working paper by Marco Gross, Jinhyuk Yoo, Hugo Rojas-Romagosa, Zulma Barrail, Salim Dehmej, and Hannah Sheldon introduces the ENV-FIBA model, a hybrid framework combining macroeconomic simulations with firm- and bank-level financial modeling. It aims to quantify how climate change and climate policies reshape economies, firms, and banking systems. By integrating the IMF’s computable general equilibrium model (IMF-ENV) with micro-level analysis, it provides one of the most holistic pictures yet of climate-related economic and financial risk.

Connecting Physical and Transition Risks

The study begins with the recognition that physical and transition risks are inseparable: natural disasters, heatwaves, and rising sea levels drive the urgent need for decarbonization, while climate policies themselves alter industrial structures and profitability. The ENV-FIBA model translates emission and temperature trajectories into sectoral and macroeconomic outcomes, and then traces their effects on firms’ revenues, debt, and default risks. This two-tier structure allows policymakers to see how a carbon tax or green investment program affects both GDP and bank balance sheets. The model stands out by jointly modeling physical and transition risks, introducing dynamic bank balance sheets that evolve with lending patterns, and emphasizing interest income as a key channel of financial impact, often more significant than outright defaults. By embedding loss-given-default dynamics and running Monte Carlo simulations for uncertain emissions data, the model captures the complexity of the real economy’s response to climate stress.

Japan as a Testing Ground for the Future

To demonstrate the model’s capabilities, the authors apply ENV-FIBA to Japan, where decarbonization poses unique challenges. More than 70 percent of Japan’s electricity still comes from fossil fuels, and seven industries, including electricity, gas, and steel, generate 80 percent of the country’s CO₂ emissions. The government’s 2023 Green Transformation (GX) Act, which invests ¥20 trillion in clean technology and introduces a carbon levy by 2028, sets the backdrop. Using data from 270,000 firms and 22 banks, the IMF team simulates how climate scenarios affect Japanese firms and lenders. Three Network for Greening the Financial System (NGFS) pathways are modeled: a Current Policies baseline, a Fragmented World with delayed action, and a Net Zero 2050 scenario. Two carbon-revenue recycling schemes are compared, one returning all proceeds to households, and another splitting them between households and renewable energy subsidies, mimicking Japan’s GX approach.

Winners, Losers, and Financial Vulnerabilities

Under the Net Zero 2050 scenario, Japan’s GDP in 2040 is only slightly below baseline levels, but it benefits from avoiding significant physical damage. Sectoral shifts are dramatic: fossil-fuel-based power, coal, and basic metals contract sharply, while renewables, transport, and business services expand. Within the power sector, renewable energy grows rapidly, offsetting fossil declines. At the firm level, emission-intensive industries such as paper, steel, and fabricated metals show the highest increases in credit risk. Companies in these sectors face greater leverage and weaker profitability, while Monte Carlo simulations reveal that high-emission firms suffer steeper funding cost increases when their true carbon intensity is uncertain.

The banking system experiences modest but uneven capital erosion. By 2040, capital ratios fall by about 0.6 to 0.7 percentage points in the Net Zero path and 0.3 points under the Fragmented World. Regional banks, with concentrated exposure to local industries, see sharper declines than diversified international banks. Around one-third of the aggregate capital impact stems from higher risk-weighted assets due to rising credit risk, and nearly 30 percent originates from non-emission-intensive sectors, revealing spillover effects through supply chains.

Dynamic Balance Sheets and Policy Lessons

A key innovation is the inclusion of dynamic bank balance sheets, showing how lending patterns and profitability evolve as industries grow or contract. For example, lending to the chemical sector declines by about 0.8 percentage points per year under Net Zero, while loans to electricity and gas rise by 1.2 points. These shifts in interest income outweigh direct credit losses, underscoring that profitability effects, not defaults, dominate long-term transitions. Accounting for such dynamics adds roughly 0.1 percentage point to the capital ratio decline, small but significant for stress-testing accuracy.

The IMF researchers conclude that the ENV-FIBA framework represents a new generation of climate-financial analysis capable of informing both policy design and supervisory stress tests. By linking chronic physical damages with transition pathways and reflecting realistic banking behavior, it delivers a richer understanding of financial resilience under climate change. The Japan case suggests that while aggregate risks appear manageable, sectoral disparities and regional exposures warrant close monitoring. The paper calls for future enhancements that incorporate market-based channels, stock-flow-consistent frameworks, and refined modeling of physical damage to credit portfolios. Ultimately, the ENV-FIBA model stands as a technical and policy breakthrough, illuminating how the global shift toward net-zero economies will reshape the contours of growth, risk, and financial stability for decades to come.