Satellite observations indicate a substantial increase in Earth's top-of-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 from observed and simulated interannual variability and the CO₂-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 far higher than projections from state-of-the-art models. This discrepancy is consistent across climate sensitivities and forcing scenarios and shows little dependence on feedback assumptions. The largest contribution arises from the shortwave component, with spatial patterns highlighting strong forcing increases over northern midlatitude oceans. These findings reveal a widening gap between observations and models, underscoring limitations in current representations of aerosol forcing.
Yukimoto et al. (Sun,) studied this question.