Scientists warn that ocean conditions that create the strongest tropical cyclones are becoming more common, increasing the risk of super typhoons with the current intensity, according to the American Geophysical Union.
Studies show that ocean areas are accumulating large amounts of heat in the North Atlantic and West Pacific, fueling increasingly intense storms.
Accordingly, this heat source is not only on the surface but also eats deep into the water layers below. It is this thick layer of warm water that helps storms maintain and increase strength as they move, instead of weakening due to rising cold water. Scientists estimate that human-caused climate change accounts for about 60-70% of the expansion of the hot spots in the ocean that form storms.
Ms. I-I Lin, professor and chair of the Department of Meteorological Sciences at the University of Taiwan (China), said that the hot spots have expanded significantly. She presented research results at the discussion session on tropical cyclones within the framework of the 2025 Annual Conference of the American Geophysical Union. The expansion increases the likelihood of severe storms making landfall in densely populated areas, she said.
For more than a decade, Ms. Lin has focused on researching the strongest storms ever recorded. After super typhoon Haiyan hit the Philippines, she and her colleagues called for considering adding a level 6 typhoon level to the cyclones far exceeding the current limit. According to the proposal, storms with winds of over 296 km/h should be classified in this new group, instead of grouped to level 5 as at present.
Data analysis for about 4 decades shows that storms reaching the "level 6" threshold are appearing more and more. In the first 3 decades, the number of these types of storms was significantly smaller than in the past 10 years. Most of them form in ocean hotspots, the largest being the eastern Philippines and Borneo, along with other areas around Cuba, Hispaniola and Florida (USA).
The study also emphasizes that warm water at deep levels plays a decisive role. When storms stir up ocean islands in other places, rising cold water can weaken the storm. At hot spots, the layer of warm water is too thick, making this process ineffective.
However, Ms. Lin noted that ocean conditions are only a necessary factor, while the atmosphere still determines whether the storm will reach extreme or not. Clearly identifying the risk of a level 6 storm is considered necessary to help cities better prepare for future disasters.
