Cyclone Nivar has caused devastation, injuries and fatalities after making landfall in southern India where torrential rainfall has lashed coastal areas of the union territory of Puducherry and Tamil Nadu state.
Despite the fact it eventually weakened into a severe cyclonic storm and had been pinpointed by the India Meteorological Department (IMD) as early as November 23rd, it still dumped vast amounts of rainfall with Puducherry recording 237mm of rainfall in eighteen18 hours, Cuddalore 246mm, and Chennai 83mm. When coupling this with strong winds, the resulting impact was felled trees and severe flooding.
The severe cyclone made landfall on November 25th, reaching wind speeds of thirty to 120 kmph. Three deaths and three casualties were recorded. Officials stated more than 100 huts were also damaged and 380 fallen trees had fallen, which have since been removed.
Adequate warnings from the IMD did allow for preventative measures to be put in place with over 120,000 people evacuated across Tamil Nadu state capital Chennai and the state’s coastal districts over the course of November 25th. Such methods served to reduce fatalities, but damage to infrastructure amongst other issues will likely be costly.
The weather system has formed over the South Andaman sea and its neighbourhood, said N. Puviarasan, director of the Area Cyclone Warning Centre at the Regional Meteorological Centre. He said “it is likely to move towards south Tamil Nadu, where heavy to very heavy rainfall is likely to occur at isolated places from December 1.”
Cyclone Nivar: A symptom of climate change’s impact in India
According to the 2019 Intergovernmental Panel on Climate Change’s (IPCC’s) Special Report On The Ocean And Cryosphere In A Changing Climate (Srocc), the global ocean has absorbed ninety percent of the excess heat generated by greenhouse gas (GHG) emissions since 1970. This has led to anomalous ocean warming, which in turn makes cyclones intensify rapidly.
Prior to Nivar’s formation in the Bay of Bengal, climate change had made the Bay of Bengal hotter. The area of the Bay of Bengal, alongside the Indian Ocean itself, is now a climate change hotspot. Speaking about temperature rise and cyclone formation, climate scientist Roxy Mathew Koll of the Indian Institute of Tropical Meteorology (IITM) in Pune, said “this time the sea surface temperatures were about 0.5-1 degree Celsius warmer, in some regions it is nearly 1.2 degree Celsius above normal.”
Alongside the fact that every 0.1 degree of warmth in the ocean gives a cyclone additional energy to feed off, an annual tropical weather fluctuation called the Madden-Julian Oscillation (MJO) also plays a role, and given its current position south of Bay of Bengal, the MJO would have provided favourable winds for a cyclone to develop. Speaking about the MJO, Koll, said
“It is a band of clouds and winds which initiates in the western Indian Ocean, then moves to the central Indian Ocean and then to the eastern Indian Ocean and then to the Pacific Ocean. So depending on where it is, it can affect the local weather conditions.”
India’s capacity to mitigate and adapt
With widespread studies indicating the effects of climate change will impact low- and middle-income countries disproportionately, events such as cyclones or periods of heavy rainfall become of greater stress to systems of healthcare, livelihoods, and the safety of the public.
In March 2019, a study analysed climate change in India’s Himalayan Region (IHR) and found that all twelve Indian states studied to be “highly vulnerable”with little capacity to resist or cope.
One of the proposed ways to adapt is further, deeper observation systems in the Indian Ocean. A multinational network of integrated observing systems for the Indian Ocean, called the Indian Ocean Observing System (IndOOS), was established in 2006. Koll is one of over sixty scientists from around the world who give recommendations and provide reports based on the IndOOS. Speaking about how climate change has already has an impact, Koll said
“In the years since it was established, the priorities have changed. Temperatures are rising rapidly in the Indian Ocean, the sea level is changing rapidly, and these changes are affecting the monsoon patterns, affecting the cyclones, the marine ecosystems.”
Cyclone Nivar’s devastating effects only highlight this grim reality.
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