Kerala deluge: Is climate change the villain?

Kerala, a 600-km-long territory flanked by the vast Arabian sea in the west and the towering Western Ghats on the east and checkered by 44 rivers and two large backwaters, suffered one of the worst droughts of its history in the summer of 2017 due to a 31-percent rainfall deficit in the two annual monsoons the previous year.

A year later, the State is now witnessing an unprecedented deluge brought about by torrential rains in the south-western monsoon in which nearly 400 human lives have already been lost while over 40 days still remain for the season to end. That is not all. Perhaps for the first time in its history, Kerala last year-end witnessed a severe cyclone, Ockhi, that killed scores of fishermen.

What could be the reason behind the extreme phenomena that have been occurring in Kerala’s weather system for at least the past five years? Weather scientists tend to view these phenomena as the results and obvious indications of climate change that can spell unimaginable havoc for the State and the entire world in the coming years.

What had caused the incessant torrential rains that pounded Kerala for 12 days since August 8 killing more than 400 persons and causing losses to the tune of over Rs 20,000 crore as per preliminary estimates, was the building up of several low pressure systems or depressions over Bay of Bengal off the Odisha coast.

Low pressure systems build up over the seas as a strategy of nature to cool the waters when the temperature levels of the sea go up. When pressure drops over a large expanse of the atmosphere, air, quite naturally, gets sucked in to that region in the form of strong winds, a process that results in rainfalls, says a scientist of the Indian Meteorological Department in Thiruvananthapuram.

“The reason for the frequent formation of low pressure systems off the Odisha coast is the unusual rise in sea temperature. Winds carrying rain clouds rush over Kerala to this region. These clouds transform into rainfall by rising further after hitting the Western Ghats. That is how it happens,” said the scientist.

Scientists point out that formation of low pressure systems in a frequency as seen in monsoon is not a usual occurrence. The formation of many low pressure systems in frequent intervals had led to heavy rainfall, they say. What Kerala is presently witnessing is a marked difference in the nature of its monsoons, they point out.

“Kerala had received lesser rains in the past four years. During that period we also suffered one of the worst droughts of the State’s history. This need not be an aberration in the natural phenomena but there is every reason to believe that these climatic shifts could be the result and indication of climate change,” a Kochi-based climatologist said.

According to this scientist, indescribable changes are taking place in the Pacific Ocean that are directly and indirectly influencing the weather patterns in other regions like the South China Sea. “Analyses show that the cyclones generated over the Pacific and South China Sea had contributed to the current spell of Kerala’s monsoon rains,” he said.

“It will be illogical to believe that climate change is a myth. It is a reality the world cannot escape or ignore. That is affecting us as well. The 2017 drought, the current rains and last year’s cyclone Ockhi must have been its symptoms. In such a situation, our system of precautions and preparedness to meet natural calamities needs extensive overhauling,” the climatologist added.