Emerging Effective Radiative Forcing in the Radiative Imbalance Since 2010

Abstract Satellite observations indicate a substantial increase in Earth's top‐of‐atmosphere (the top of the atmosphere (TOA)) radiative imbalance since 2010. We estimate trends in effective radiative forcing (ERF) by separating TOA flux changes into forcing and response components, using feedback parameters derived from observed and simulated interannual variability and the CO 2 ‐forced response. From 2010 to 2024, ERF trends are ∼1.0 W m −2 per decade for both net and shortwave fluxes, exceeding those for 2001–2024 and substantially larger than projections from state‐of‐the‐art models. This discrepancy persists across a wide range of climate sensitivities and forcing scenarios and shows limited sensitivity to feedback assumptions. The largest contribution arises from the shortwave component, with spatial patterns indicating particularly strong forcing increases over northern midlatitude oceans. These results suggest that the gap between observations and models is widening, although the contribution of internal variability cannot be entirely excluded.