Cyclone Nivar: Could climate change be a preventive blow?

Cyclone Nivar, which hit the shores of Puducherry last night, has turned northwest today. But, Puducherry and Tamil Nadu are witnessing incessant rains in many parts and the storm has caused significant damage in the region. According to a statement given by Additional Chief Secretary of Tamil Nadu Atulya Mishra to the media, so far 3 people have died in the state due to the storm and 3 more are currently injured.

Experts believe that there are strands of prevention related to climate change, and this is becoming fatal because of it.

Sea surface temperature and storm strength. The warm ocean temperatures brought on by global warming due to human greenhouse gas emissions support the formation and rapid intensification of tropical (tropical) cyclones. There has been a global increase in the intensity of the strongest storms in recent decades: a study published in June found that the proportion of the strongest storms has been increasing by about 8% in a decade.

A recent study concluded that “sea surface and subsurface conditions played an important role in the origin and intensity of Cyclone Ockhi”, a very similar cyclone that hit the same area about three years ago. , Which led to 844 deaths. Like other parts of the world, sea surface temperatures in the Bay of Bengal have been steadily increasing over the last decades.

Rapid intensification (rapid intensity). According to several studies, an increasing proportion of tropical (tropical) cyclones are rapidly evolving, known as rapid intensification (rapid intensity) – these changes are associated with climate change. Warm sea water is a factor that increases rapid intensification (rapid intensity) speed, so high sea temperatures make it more likely due to human greenhouse gas emissions. Rapid intensification (rapid intensity) is a threat because it makes it difficult to predict how a storm will behave and therefore makes it difficult to prepare before the storm’s landfall.

Warmer climate and more intense rainfall. The Earth’s atmosphere is heating up due to carbon emissions. The warm environment can hold more water, which causes excessive rainfall during cyclones, increasing the risk of flooding. Scientists have linked the increase in atmospheric humidity directly to human-caused climate change. Record-breaking rain events have increased significantly in recent decades globally due to global warming, and scientists predict that cyclones will increase rainfall with continued climate change.

High sea level and increased storm surge. Potential storm surge from a cyclone are often the most dangerous risks from a storm. Climate change-related storm surge can be caused by rising sea levels, increasing size, and rising storm wind speeds. Global sea levels have already risen by about 23 cm as a result of human carbon emissions – severely increasing the distance to which a storm can reach.

In addition, tropical (tropical) cyclones in the Bay of Bengal are affected by El Niño – Southern Oscillation (ENSO), a meteorological event that affects wind patterns in some areas of the Pacific (Pacific) Ocean and Affects sea surface temperatures with results in different parts of the world.

Scientists have found a relationship between the cooler phase of ENSO, known as La Niña, and the increasing tropical (cyclonic) cyclonic activity in the Bay of Bengal. Because we are currently experiencing the La Niña period, this may be one of the underlying reasons for the creation of Cyclone Prevention.
Reacting to this, Dr. Roxy Mathew Koll, Scientist at the Indian Institute of Tropical Meteorology and lead author of the IPCC (IPCC) Oceans and Cryosphere report, says “La Niña is in the Pacific (Pacific) region right now, Which is the cooler state of the Pacific (Pacific) that makes local environmental conditions in the Bay of Bengal eligible for cyclogenesis. “He adds,” During the last 40 years, six cyclones – in the severe cyclone category – In November, Tamil Nadu hit the coast. Five of these six occurred during La Niña conditions in the Pacific (Pacific). So that means that to some extent, during this time we were in a cyclone in the Bay of Bengal. Were expecting the weather – and it’s no surprise.

Now if we look at local conditions, the role of climate change is visible. The case of cyclone prevention is similar to that of Cyclone Ockhi. In November 2017, Cyclone Ockhi rapidly increased from a moderate cyclone to a very severe cyclone in 24 hours, resulting in 844 deaths in India and Sri Lanka. We found that the unusually warm sea temperature supported its development from a depression to a cyclone in 9 hours and then to a very severe cyclone in 24 hours.

“The Bay of Bengal is part of the warm pool area, where temperatures are around 28–29 ° C and sometimes over 30 ° C in November. These high temperatures are generally helpful for cyclogenesis. On top of this is the global warming element – at this time temperature anomalies are around 0.5–1 ° C and in some areas reach 1.2 ° C based on buoy and satellite estimates. Every 0.1 ° C means additional energy to sustain and develop the cyclone. We find that such a hot state can support the rapid intensification (rapid intensity) of cyclone prevention as in the case of cyclone Ockhi.

“Locally, winds also favor cyclone formation. The Madden Julian Oscillation (MJO) – a band of clouds moving eastward – is currently active south of the Bay of Bengal. It is therefore helpful to bring rapid intensification (rapid intensity) from cyclogenesis and climate change due to the favorable atmospheric conditions of the ocean, as a result we have extreme cyclone prevention. ”

“As we develop cyclone prevention,” says Dr. Anjal Prakash, Director of Research and Assistant Associate Professor at Bharti Institute of Public Policy, Indian School of Business, and Coordinating Lead Writer of the IPCC (IPCC) and Cryosphere for Oceans Following, places such as coastal and north interior Tamil Nadu, Puducherry, south coastal Andhra Pradesh and Rayalaseema have been categorized as red, meaning these areas are expected to be severely affected.

“Since the beginning of 2020, this is the 8th such event in the Indian Ocean and the Bay of Bengal. Of these eight recorded incidents of cyclones, Amfan and Nisarg were super cyclones, while speed and containment are considered very severe cyclonic events. There were four relatively small depressions this year which also increased heavy rain and wind.

“IPCC scientists have been warning about such incidents. The most recent report that covered the oceans and the cryosphere explicitly warned that if global warming was not stopped, the number and severity of these cyclones would increase.

“In 2019, 12 such incidents were recorded, while in 2020 Cyclone Prevention is the 8th such event affecting life in major ways.

The actual impact of cyclone prevention can only be measured later when it makes landfall on 25 November, with previous experiences suggesting that excessive rains in cities and settlements will lead to flooding. Our infrastructure is not geared towards tackling such severe climate events. Priority will be given to evacuating people from low-lying areas and Danger Zone so that their lives can be saved. Even more important is that we should agree our infrastructure towards such climatic events and plan for adapting to future events.

“Changing climatic conditions are adding more cyclonic events every year and so adaptation to these events can save the lives of millions of people, especially the poor and marginalized.”