Global exposure to flooding from the new CMIP6 climate model projections

Abstract

Estimates of future flood risk rely on projections from climate models. The relatively few climate models used to analyze future flood risk cannot easily quantify of their associated uncertainties. In this study, we demonstrated that the projected fluvial flood changes estimated by a new generation of climate models, the collectively known as Coupled Model Intercomparison Project Phase 6 (CMIP6), are similar to those estimated by CMIP5. The spatial patterns of the multi-model median signs of change (+ or −) were also very consistent, implying greater confidence in the projections. The model spread changed little over the course of model development, suggesting irreducibility of the model spread due to internal climate variability, and the consistent projections of models from the same institute suggest the potential to reduce uncertainties caused by model differences. Potential global exposure to flooding is projected to be proportional to the degree of warming, and a greater threat is anticipated as populations increase, demonstrating the need for immediate decisions.

Anthropogenic climate change has changed frequency of past flood during 2010-2013

“…Therefore, it is important to analyze changes in the frequency and magnitude of flooding to develop adequate adaptation and mitigation strategies. For this purpose, flood changes associated with climate change have been projected in the near (e.g., 2030-2050) and far (-2100) future, driven by anthropogenic climate change scenarios (Dottori et al 2018;Hirabayashi et al 2013;Hirabayashi et al 2021); often, the results of the warmest scenario (e.g., RCP8.5) have been used to capture a prominent climate change signal.…”

“…As most climatic attribution studies have focused on single-step direct output of climate models (e.g., temperature and precipitation), few studies have investigated event attribution to river flooding. Since studies of flood projection (Hirabayashi et al 2013;Hirabayashi et al 2021;Sharma et al 2018) have demonstrated that the direction of the changes (wet or dry) in precipitation and flooding is not consistent in spatiotemporally because of several hydrological processes, event attribution of river discharge will enhance our understanding of the effects of climate change on flood risk.…”

Assessment of damage during the formation and passage of mudflows in the Tashkent region

“…Precipitation is considered dangerous, the amount of which in 12 hours or less exceeds 15 mm in case of rain and 7 mm in case of snow. The corresponding criterion for especially hazardous precipitation, which is considered a natural phenomenon, is considered to be fallout for the same period of 30mm with rain and 20mm with snow [21][22][23][24][25][26][27][28].…”

Toward Improved Comparisons Between Land‐Surface‐Water‐Area Estimates From a Global River Model and Satellite Observations

“…Runoff was provided at 0.25° pixels, and therefore was distributed to each unit catchment according to the areal proportion of the unit catchment in the corresponding grid. The model has been validated in recent studies by Eilander et al (2020) and Hirabayashi et al (2021). In this study, only a scatter comparison of the mean discharge and annual maximum discharge with discharge observations from Global Runoff Data Center (GRDC, https://portal.grdc.bafg.de) for 172 gauges over the world is provided as Figure S1.…”