Understanding Extreme Weather in a Changing Climate

ClimaMeter is an experimental rapid framework for understanding extreme weather events in a changing climate based on looking at similar past weather situations. Find out more here and follow us on X

Human-driven climate change have enhanced Guangdong-Hong Kong floods impacts, favoring more severe precipitations

In September 8, 2023, torrential rains from the remnants of Typhoon Haikui led to severe flooding in Guangdong and Hong Kong, causing widespread disruption and at least two fatalities. Hong Kong saw record-breaking rainfall levels, with depths exceeding 1.5 meters in flooded streets, leading to closures of schools, the stock exchange, and offices, while also affecting nearby areas in Guangdong province.

Our analysis finds that cyclones leading to Guangdong-Hong Kong floods similar to that observed in September 2023 are up to 5 mm/day wetter in the western Guangdong province than they would have been in the past and up to 3 mm/day dryer in the coastal part. We interpret the Guangdong-Hong Kong floods as an event whose characteristics can mostly be ascribed to human driven climate change.  For the Guangdong and Hong Kong floods we have low confidence in the robustness of our approach given the available climate data, as the event is largely unique in the data record.

Photo: A view of a flooded area after heavy rains, in Hong Kong, China, September 8, 2023  REUTERS/Tyrone Siu

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