Carbon-aware ramping-driven assessment of multi-duration energy storage requirements under extreme climate events

• A carbon-aware framework is developed to assess multi-timescale storage requirements. • Climate-driven net load modeling captures supply–demand mismatch under extreme weather. • A dual-layer temporal decomposition is proposed to separate short- and long-duration storage. • Storage needs respond nonlinearly to the frequency and severity of extreme climate events. • Carbon pricing significantly reshapes the structure and intensity of storage requirements. With the rapid growth of renewable penetration, accurately quantifying multi-timescale flexibility requirements has become a central challenge for power system planning. Yet existing flexibility and storage adequacy assessment studies often evaluate climate extremes and carbon constraints separately, and rarely translate climate-driven net-load ramping into differentiated requirements for short- and long-duration storage. This study proposes a carbon-aware, ramping-driven assessment framework for multi-duration energy storage requirements under extreme climate events. We first develop a meteorology-driven net load modeling approach that integrates observations and CMIP6 projections to capture climate-induced renewable suppression and temperature-sensitive demand fluctuations. We then quantify ramping stress across multiple time scales and construct a carbon-constrained multi-timescale storage planning model with a dual-layer temporal decomposition, explicitly separating short-duration (intra-day ramping) and long-duration (inter-day/seasonal balancing) storage dynamics. Case studies for Northeast China show that extreme-event frequency and severity induce nonlinear and coupled shifts in storage demand patterns across time scales: In the extended sensitivity analysis, when extreme-event frequency increases by 15%, long-duration storage duration rises by 23.4%, while short-duration storage power demand and duration decrease by 39.5% and 16.2%, respectively. Carbon emission prices further amplify the sensitivity and volatility of storage requirements, especially under intensified climate extremes. These findings indicate that neglecting ramping-driven climate risks and carbon constraints can substantially underestimate flexibility needs, and provide quantitative support for climate-resilient, carbon-constrained storage deployment and planning.