KOCHI: Global warming is having its worst impact on the state as it is tucked between the Western Ghats on the one side and the sea on the other. This is reflected in the recurring number of extreme weather events in recent years, starting with back-to-back droughts in 2015 and 2016, followed by the Ockhi cyclonic storm last year, said scientists.
“We are most likely to see both ends of extreme weather situations due to global warming,” said Dr Abhilash S, associate director, Advanced Centre for Atmospheric Radar Research, Cusat. He said the Arabian Sea and the Bay of Bengal are warming at a higher rate than other oceans, severely affecting the weather patterns in Kerala. “Arabian Sea and the Bay of Bengal are warming at the rate of 1.1 degree Celsius in about 120 years, compared to other oceans that warm at the rate of 0.8-0.9 degree Celsius in the same period,” he said.
Due to global warming, the “dipole” formation over the western and eastern parts of the Indian ocean, commonly referred as IOD (Indian Ocean Dipole) or the Indian Nino —the irregular oscillation of sea-surface temperatures, in which the western Indian Ocean becomes alternately warmer and then colder than the eastern part of the ocean — has been the strongest now. “We are seeing the strongest IOD since 1997,” explained Dr Abhilash.
Dr Renoj J Thayyen, scientist, National Institute of Hydrology, Roorkee, pointed out that the recurrence of extreme climate events, especially in Kerala, is becoming more frequent due to climate change. “The 2018 floods were termed as a once-in-a-century event, but these extreme events are becoming more frequent,” said Thayyen.
Similarly, there used to be thunderstorms between October and November rain. Now, the event is not as frequent, said Dr Thayyen, a glaciologist who studied thinning of Gangotri glaciers. “Big climate events can happen anytime and the uncertainty has especially increased in Kerala due to our geographical position,” he said. Dr Abhilash said the central Arabian Sea, which normally cools down after monsoon rains, did not do so this time due to the abnormal warming of the sea.