Blockchain-embedded carbon emission allowance pledge financing: Resolving maturity mismatch with machine trust and collateral flexibility

Carbon emission allowances (CEAs), as one of the few “hard assets” of small and medium-sized enterprises (SMEs), hold significant potential for pledge financing. However, due to its compliance period constraints, CEA pledge financing faces fundamental challenges because of the inherent maturity mismatch between short-term compliance cycles (one year) and long-term financing needs (years). To address this issue, this study introduces a blockchain-driven cross-compliance-period CEA pledge financing framework that integrates 1) smart contract-driven automated CEA verification and transfer, 2) high repayment willingness ensured by network-wide broadcasting and tamper-proof records, and 3) a dynamic pledge rate adjustment mechanism. Using 2022–2023 market data, analysis based on the segmented Black-Scholes option pricing model demonstrates that this new framework not only enables enterprises to release carbon assets during the loan period without the need for supplementary collateral, but also achieve a higher pledge rate. However, it is worth noting that elevated market volatility and weak repayment capacity exert a negative influence on the bank’s pledge rate. By leveraging blockchain’s “machine trust” to create a generalizable mechanism for dynamic collateral management, this study offers a novel, technology-driven paradigm that addresses structural maturity mismatches in carbon finance and provides theoretical insights for the design of resilient, long-term green financing systems.