Locally opposite responses of the 2023 Beijing–Tianjin–Hebei extreme rainfall event to global anthropogenic warming

Abstract

The effect of anthropogenic warming on extreme rainfall events is a hot topic in this era of global warming, and increasing attention is being paid to its impact at regional and local scales. We explore the localized response of precipitation during the high-impact “23·7” extreme rainfall event in the Beijing–Tianjin–Hebei region under anthropogenic warming using ensemble convective-permitting simulations. We identify two sub-regions with opposite responses: anthropogenic warming decreased (increased) precipitation in the northern (southern) sub-region of the Beijing–Tianjin–Hebei area. Further analysis shows that anthropogenic warming intensified the remnant of Typhoon Dusuari and increased rainfall in its inner core but decreased rainfall in the peripheral spiral rain band. These are the main reasons for the locally inconsistent responses of extreme rainfall to anthropogenic warming. We emphasize that anthropogenic warming, as a global background signal, directly affects the intensity and structure of specific weather systems rather than local precipitation. A high-impact extreme rainfall event, therefore, cannot always be simply attributed to climate warming enhancing precipitation at every location in a particular region.