Preliminary studies by climate scientists suggest that unusually hot oceans – caused by human-driven climate change – intensified Super Typhoon Ragasa, which battered the Asia-Pacific region this week.
French research group ClimaMeter, which uses a rapid attribution framework to understand extreme weather events, examined changes in weather patterns since 1950, comparing conditions between 1950–1986 and 1987–2023.
“ClimaMeter found that cyclones similar to Super Typhoon Ragasa are around 1°C warmer, up to 10 mm/day (10%) wetter, and slightly windier by up to 4 km/h in the present compared to the past. They contribute to more extreme rainfall and flooding risks, particularly in the Philippines’ mountainous terrain and neighboring coastal regions. We interpret Super Typhoon Ragasa as an event of exceptional meteorological conditions whose characteristics can mostly be ascribed to human driven climate change,” it said in a Thursday press release.
Ragasa underwent an extreme rapid intensification between September 20 and 21, strengthening by 137kph in just over 24 hours. It left three dead in the Philippines and 17 casualties in Taiwan.
In Hong Kong, the super typhoon triggered the Hong Kong Observatory to raise its highest-level storm signal, T10, for almost 11 hours and brought the city to a standstill, grinding public transport, the airport, work, and schools to a halt.
Climate crisis
US climate science NGO Climate Central said that sea surface temperatures in the western Pacific were 0.7 to 1.1°C above average whilst the storm intensified: “Exceptionally warm sea surface temperatures along the typhoon’s path, through the Philippine Sea, were made at least 10 to 40 times more likely due to human-caused climate change.”
Daniel Gilford, a meteorologist and climate scientist at Climate Central, said: “Super Typhoon Ragasa intensified over waters made hotter by human-caused climate change. These exceptionally warm sea surface temperatures increased the chances that Ragasa would rapidly intensify — and it did, becoming the most powerful typhoon this year.”
Tropical cyclones – which get their energy from warm ocean water – are strengthening and becoming ever more destructive because of warming seas. Over 90 per cent of excess heat in the atmosphere is ending up in oceans, according to NASA, as rising greenhouse gases prevent it from escaping to space.
