Human influence on historical heaviest precipitation events in the Yangtze River Valley

Abstract

With the recurrence of high-impact extreme weather and climate events and the growing demands by the public to know the causes after the events, event attribution has emerged as a frontier of climate change research. Typically, an event attribution study focuses on one individual extreme event that has just occurred. Studies rarely examine human influence on multiple extreme events in different times of the past. Here we conduct a comprehensive attribution analysis on a number of the heaviest precipitation events in the Yangtze River Valley (YRV) during the past 100 years. We start by defining extreme precipitation events as the heaviest precipitation over a fixed area size that is of direct relevance to flood preparedness and management. When examining the events over the historical time, we allow the precise locations of the area to change in different years. Four extremely strong events are identified, and they happened in the summer of 1931, 1954, 1998 and 2020. A clear difference in the impacts of greenhouse gases (GHGs) and anthropogenic aerosols (AAs) on the events was found. Their impacts were negligible in the early period and became more and more discernible since the late 20th century. The temporal change of human influence on the events shows gradual strengthening impacts of GHGs and AAs with time. Their competing effects led to a slight human influence and then gradually increasing influence on extreme precipitation after the 21st century. GHGs have exerted a larger influence on short-duration precipitation events while AAs have had a larger influence on monthly mean precipitation. The more extreme the precipitation event, the clearer the anthropogenic influence.

Differing Contributions of Anthropogenic Aerosols and Greenhouse Gases on Precipitation Intensity Percentiles Over the Middle and Lower Reaches of the Yangtze River

“…Meanwhile, Z. Wang et al. (2023) analyzed four extreme Meiyu precipitation events that occurred in MLYR in 1931, 1954, 1998, and 2020, and their conclusions partially corroborate our findings. The competitive effects of GHG and AA forcings make it challenging to detect the signal of human activities in very heavy precipitation days, as these signals can be intermingled with natural variability effects.…”

Exploring the Best-Matching Precipitation Traits in Four Long-Term Mainstream Products over China from 1981 to 2020

“…The precipitation seasonality is important to agricultural production, vegetation growth, ecological and socio-economic development [16][17][18]. The frequency and intensity of heavy precipitation events are increasing globally and regionally with global warming [19][20][21]. The amount of daily precipitation could considerably alter evapotranspiration and runoff related to river discharges and ecosystems.…”

A comparative analysis of the attribution of extreme summer precipitation in south and north parts of the East China monsoon region—with the year 2020 as an example

“…2/3 of the land area of the Northern Hemisphere has experienced enhanced extreme precipitation, and multi‐model simulations of precipitation response to anthropogenic forcing are consistent with changes in terrestrial extreme precipitation observed in the Northern Hemisphere (Min et al, 2011; Zhang et al, 2013). The more extreme the precipitation event, the clearer the anthropogenic influence (Wang et al, 2023). The human influence dominated by the GHG effect has intensified extreme precipitation, especially in continental and regional extreme precipitation (Chen & Sun, 2017; Dong et al, 2021; Kirchmeier‐Young & Zhang, 2020; Sun et al, 2021; Xu et al, 2022).…”