Abstract
The ongoing increases in anthropogenic radiative forcing have changed the global water cycle and are expected to lead to more intense precipitation extremes and associated floods. However, given the limitations of observations and model simulations, evidence of the impact of anthropogenic climate change on past extreme river discharge is scarce. Here, a large ensemble numerical simulation revealed that 64% (14 of 22 events) of floods analyzed during 2010-2013 were affected by anthropogenic climate change. Four flood events in Asia, Europe, and South America were enhanced within the 90% likelihood range. Of eight snow-induced floods analyzed, three were enhanced and four events were suppressed, indicating that the effects of climate change are more likely to be seen in the snow-induced floods. A global-scale analysis of flood frequency revealed that anthropogenic climate change enhanced the occurrence of floods during 2010-2013 in wide area of northern Eurasia, part of northwestern India, and central Africa, while suppressing the occurrence of floods in part of northeastern Eurasia, southern Africa, central to eastern North America and South America. Since the changes in the occurrence of flooding are the results of several hydrological processes, such as snow melt and changes in seasonal and extreme precipitation, and because a climate change signal is often not detectable from limited observation records, large ensemble discharge simulation provides insights into anthropogenic effects on past fluvial floods.
Highlights
Flooding is a common major natural hazard in many areas of the world, and its frequency and magnitude are expected to increase with climate warming
The results showed that the occurrence of floods was enhanced by anthropogenic radiative forcing during the target years (2010-2013) in wide areas at northern high latitudes including in a wide area of northern Eurasia, part of northwestern India and central Africa, while the occurrence of floods was suppressed in part of northeastern Eurasia, southern Africa, central to eastern North America and South America (Fig. 2)
4 Conclusions The event attribution of historical flood events showed that anthropogenic climate change affected 64% (14 of 22) of the floods analyzed, with increased occurrence caused by heavy rainfall, and increased or decreased snowmelt flood events
Summary
Flooding is a common major natural hazard in many areas of the world, and its frequency and magnitude are expected to increase with climate warming. This study evaluated the impact of anthropogenic climate change on the probability of historical large flood events based on river discharge derived from large ensemble climate experiments to investigate whether possible mechanisms of the past changes in floods due to climate change have already been revealed. For this purpose, we analyzed 22 flood events occurring during the target period at a global scale, rather than focusing on specific flood events, to provide an overview of the effects of past anthropogenic climate change on flood events
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
