European Central Bank details climate factors that reduce collateral values for climate exposed corporate bonds

In a blog post, the European Central Bank explained that it introduced climate factors into its collateral framework on 15 June 2026. The new factors add a forward-looking climate adjustment to the valuation of corporate bonds used as collateral in Eurosystem lending operations, on top of existing haircuts. Bonds issued by firms that are more exposed to climate transition shocks will receive a larger valuation reduction, which can lower the amount banks can borrow against them. The ECB said the immediate effect is expected to be limited because borrowing levels are low and corporate bonds account for a limited share of collateral use. The framework works in two steps. First, the ECB assigns each eligible corporate bond an uncertainty score based on a sector-level stressor, firm-level exposure and asset-level vulnerability. Exposure is assessed using greenhouse gas emissions, decarbonisation targets and the quality of climate-related disclosures, while vulnerability is linked to the bond's residual maturity. Second, that score is converted into a climate factor within a narrow range set by the Governing Council, so it functions like an additional haircut for climate-related uncertainty. The ECB said utilities, materials and transportation tend to have lower climate factors, while software and consumer services tend to have higher ones, although differences within sectors remain significant. The Governing Council will regularly review the scope and calibration of the climate factors to reflect new data, regulatory developments and advances in risk assessment capabilities.