The European Central Bank just put a price tag on climate risk. On July 29, the ECB announced a new “climate factor” within its collateral framework that will apply additional haircuts to certain corporate bonds used as collateral in Eurosystem operations. Think of it as the central bank telling lenders: if you want to borrow against bonds from companies exposed to climate transition risk, those bonds are now worth a bit less at the window.
The policy targets marketable bonds issued by non-financial corporations and their affiliates, with implementation set for the second half of 2026.
How the climate factor actually works
Collateral haircuts are already a standard feature of central banking. When a bank pledges an asset to borrow from the ECB, the central bank doesn’t accept that asset at face value. It applies a discount, a haircut, to account for the risk that the asset could lose value before the loan is repaid. A 10% haircut on a bond worth 100 million euros means the bank can only borrow against 90 million euros of value.
The new climate factor adds an extra layer to that existing discount. Its calibration is based on an “uncertainty score” that pulls from two main inputs: sector-specific stress factors identified in the Eurosystem’s 2024 climate stress test, and issuer-specific vulnerability scores from the Corporate Sector Purchase Programme’s climate scoring methodology.
