Climate change is the reason for the excessive rainfall and flooding that devastated Kerala in August, the Hindustan Times quoted India Meteorological Department Director General KJ Ramesh as saying on Friday.

At least 483 people in the state died in rain-related incidents this monsoon. During the worst phase of the flooding in August, 14,50,707 people were living in relief camps. It was dubbed one of the “worst floods” that state has faced in a century.

“Kerala flooding has happened because of extreme rainfall during monsoon 2018 and large amounts of water stored in catchments of reservoirs, which had to be released,” Ramesh said. “It is because of climate change that such disasters happen.” He was speaking at a national media briefing on climate change organised by the Centre for Science and Environment.

Rainfall data from 1951 to 2016 shows that rainfall events of more than 10 to 15 cm per day – categorised as very heavy rain – are increasing, while days that receive less than 5 cm are gradually decreasing. “This is proof of climate change impact,” Ramesh said. “The Intergovernmental Panel on Climate Change’s fifth assessment report had said such impacts will be pronounced.”

Ramesh said more than 75% of the geographical area in Kerala was vulnerable to flooding. “This, coupled with unprecedented rainfall, led to extreme flooding,” he added.

The Met department chief said the state received two consecutive spells of rain from August 8 to August 10 and August 14 to August 17. By the end of July, the 35 reservoirs in the state were at full reservoir level and had no buffer storage to “accommodate the heavy inflows from August 8”. “Continued exceptionally heavy rainfall in August in the catchment areas had compelled the authorities to resort to heavy releases downstream into the rivers leading to widespread flooding,” he pointed out.

Ramesh also said that the number of cyclones have increased from 10 to 18 every year, reported The Indian Express. He also said that the quantum of precipitation, which was 13 days, has reduced to 10 days.

On Cyclone Ockhi that hit Tamil Nadu and Kerala in 2017, Ramesh said: “The rapid intensification of the cyclone is due to anomalous warming of ocean, a direct result of global warming.”

SK Dash, a professor at the Centre for Atmospheric Sciences of Indian Institute of Technology-Delhi, said research shows that heavy rainfall incidents are increasing and are followed by long stretches of dry days. “Monsoon rainfall is known for continuous rainfall but that is changing,” he added.

Last month, a draft report prepared by the Ministry of Earth Sciences said the India Meteorological Department had under-reported the intensity of rainfall in Kerala even as it accurately predicted heavy rain.