Thiruvananthapuram, Oct. 20 -- The havoc wrought by heavy rain in Kerala, where 39 people were killed last week, has a clear imprint of the climate crisis, say weather scientists. In the last three years, the state has seen at least four flash floods of which the 2018 flooding was the worst.

Scientists link the fast-changing weather pattern to the rise in surface temperature of the Arabian Sea in the last two decades, leading to higher cyclonic circulations.

According to the India Meteorology Department (IMD), there was a 52% increase in cyclonic movement over the Arabian Sea between 2001 and 2019, and an 8% decrease in the Bay of Bengal during the same period. IMD statistics showed that nine cyclonic or major depressions had formed in 20...