Is climate change linked to rain fury in Bihar and Uttar Pradesh?

New Delhi, Oct 01: Could climate change be the reason behind rain fury in Bihar and Uttar Pradesh? Leaders and scientists certainly think so.

As incessant monsoon rains has wreaked havoc across North India, especially Bihar and Uttar Pradesh, with more than 150 reported deaths. Of these, 104 deaths have been reported from Uttar Pradesh alone, while the toll in Bihar has climbed to 40.

Patna is the worst hit with several schools shut and the life has been thrown out of gear.

Nitish Kumar blames climate change

Bihar Chief Minister Nitish Kumar has blamed swift climate change for the floods in the state.

"The imbalance in nature, climate change... At the early stage, there was heavy rainfall in a particular area and drought somewhere else. The level of water in Ganga has gone up, causing distress to people living near the river," he told reporters.

What studies reveal

Scientists attribute it to the rising temperatures, creating a more moisture-laden monsoon system and higher levels of precipitation.

Studies have found that a threefold increase in widespread extreme rainfall over central India since 1950, as a result of warming in the northern Arabian Sea. Another study​ found that rainstorms in North India have become 50% more common and 80% longer.

​One important reason for this is that an atmosphere that is warmer can hold more water vapour. The world has so far heated ​ about 1°C​ since pre-industrial times and, around the world, heavy rainfall has ​ increased.

Is this linked to climate change?

Scientists looking at a particular heavy rainfall event that hit northern India in 2013 found that​ climate change made the event more likely​ . The ​study​ used ‘event attribution', a methodology that looks at the influence of human-caused warming on particular weather events. The resulting flooding, in Uttar Pradesh, Himachal Pradesh and Uttarakhand, killed more than 5,800 people.

"The trend of more unpredictable and extreme rainfall in India ​ reflects what scientists predict​ will happen due to climate change, particularly if emissions do not fall. Temperature rise is likely to make India's summer monsoon much more unpredictable," ​according to​ the World Bank.

It report also says that continued high emissions would mean a monsoon so extreme it currently happens only once a century would instead happen once a decade. Another ​ study​ found that monsoon rainfall will become more unpredictable on a day-to-day basis, with variability increasing up to 50% this century if emissions continue to rise.

What scientists has to say

"Parts of Bihar and the Uttar Pradesh-Uttarakhand belt already exhibits a rising trend in terms of the number of heavy rainfall events. Though we cannot pinpoint each event to climate change unless we do in-depth attribution study, it is likely that the rise in global and local temperatures have contributed to the observed anomalies in rainfall," said Dr Roxy Mathew Koll, Co-Author, Special Report on Oceans and Cryosphere - IPCC, Scientist, Indian Institute of Tropical Meteorology.

"Specifically, widespread heavy rains resulting in floods are on a rise across the central and west coast, and parts of north/north-east India," he added.

"There was high moisture incursion from the Bay of Bengal associated with monsoon low pressure system and a strong monsoon trough in that region. This high availability of moisture maybe the climate change factor which we need to pay attention to. IMD had predicted this event on 26th September 2019, well in advance," he added.

Monsoon arrival

Monsoon made a delayed entry over Kerala on June 8, a week after its normal date of arrival. The deficiency in June was 33 per cent but it picked in later months.

"August recorded 115 per cent rainfall of the LPA, first time since 1996 (119 per cent). Similarly, the rainfall recorded in September (152 per cent of the LPA) was second highest after 1917 (165 per cent of the LPA). July recorded 105 per cent of the rainfall of the LPA," according to PTI.

Monsoon rainfall break-up

With 110 per cent rainfall of the LPA this year,India recorded the highest rainfall this monsoon since 1994.

"After 1931 this is the first time the seasonal rainfall is more than LPA even after the June rainfall deficiency was more than 30 per cent of LPA. After 2010, this is the first time, rainfall during all the last three months (July to September) was above LPA," the IMD said.

"The highest cumulative rainfall during August-September (130 per cent) has been recorded in 2019 after 1983 (142 per cent)," the IMD added.

Most states have witnessed flood this year, leading to large scale destruction and loss of lives.