Cyclone Amphan was largest source of displacement in 2020, says latest IPCC report
The cyclone intensified from a category 1 cyclonic storm to a category 5 super cyclone in less than 36 hours, before finally hitting the West Bengal coast on May 20, 2020. The IPCC report also hints that the lockdown, prompted by the Covid-19 pandemic, may have played a role behind the formation and intensification of the cyclone.
Cyclone Amphan, which hit the West Bengal coast in May 2020 amidst the Covid-19 pandemic, was the largest source of displacement that year, says the latest report of the Intergovernmental Panel on Climate Change (IPCC).
It was the first super cyclone to form in the Bay of Bengal since 1999 and one of the fiercest to hit West Bengal in the last 100 years. It killed around 100 people in the state alone.
“Cyclone Amphan was the largest source of displacement in 2020, with 2.4 million displacements in India alone, out of which around 800,000 was pre-emptive evacuation by the authorities,” the report says.
The second part of the IPCC’s Sixth Assessment Report (AR-6) was released earlier this week. The report has sounded the warning for extreme weather events across India.
The Internal Displacement Monitoring Centre, a Geneva-based international NGO had earlier estimated that the cyclone had triggered nearly five million evacuations across Bangladesh, India, Myanmar and Bhutan in May, making it the largest disaster displacement event of the year globally.
The ministry of earth sciences, however, has recently said in the Lok Sabha that there is no established study for India providing a quantified attribution of climate change triggering migration or displacement of people.
“While many studies monitor extreme events in the environment, the science of attribution of these changes particularly to climate change is far more complex and currently an evolving subject. Most studies of attribution so far have relied generally on mathematical modelling of climate change impacts,” Bhupender Yadav, union environment minister told the Lok Sabha in February this year.
The cyclone intensified from a category 1 cyclonic storm to a category 5 super cyclone in less than 36 hours, before finally hitting the West Bengal coast on May 20, 2020. The IPCC report also hints that the lockdown, prompted by the Covid-19 pandemic, may have played a role behind the formation and intensification of the cyclone. In May 2021 another cyclone named Yaas had ravaged the West Bengal and Odisha coast.
“The combined decline of both aerosols (due to COVID-19 related lockdowns) and clouds may have contributed to the increased sea surface temperature, further compounding the climate change related warming of the oceans,” the report says.
Experts like KJ Ramesh former director general of the India Meteorological Department, however, differed. He said: “Oceanic aerosols, like sea salt and water, are the primary sources when a cyclone forms or intensifies over the sea. The lockdown may have brought down pollution on land but that had very little effect on cyclones. Continental aerosols like pollutants hardly help in the formation of a cyclone.”
The report says that even though the dense mangrove forest of the Sunderbans, may have helped to reduce the impact of the cyclone, the cyclone inflicted damage to the delta as it bore the first brunt of the cyclone.
The Sunderbans is the world’s largest mangrove delta and spreads over 10000 sq km in India and Bangladesh. It is the only mangrove where tigers live.
“As per the initial estimates the cyclone damaged around 1,600 sq km of mangrove forest in the Sunderbans, the world’s largest mangrove delta and the only mangrove where tigers live. Kolkata too lost a substantive part of its green cover,” says the report.
The IPCC report also suggests that hyper-salinity, storm effects sediment deposition, fishery development and land erosion are mainly responsible for most part of Sunderbans mangrove degradations leading to loss of livelihood. In the Sunderbans of Asia, climate change is expected to increase river salinisation, which in turn could significantly negatively impact the valued timber species, Heritiera fomes- the Sundari tree from which Sunderbans derives its name.
“Rising salinity level in the delta is taking a toll on several mangrove species such as Sonneratia apetala, Nypa fruticans and Bruguiera gymnorhiza among others. Their growth is becoming stunted as they can’t withstand salinity above 20 psu (practical salinity unit). The average salinity of sea water in Bay of Bengal is 33 psu (which is equal to 33 gram of salt in one litre of water). Because of reduced sweet water flow and intrusion of salt water from the sea these trees are either dying or suffering from stunted growth,” said Abhijit Mitra, former head of the marine science department of Calcutta University.
The Forest Survey of India’s State of Forest Report 2021 released in January this year revealed that Sunderbans lost its two sq km of its ‘very dense mangrove cover’ between 2019 and 2021. Experts had said that the rising salinity levels and increasing number of cyclones are taking a toll on the mangrove forest.
“There has to be combination of strengthening green and blue infrastructure. While green infrastructure includes more focus on urban greening and biodiversity protection for different climate anomalies, blue infrastructure refers to protecting and enriching water bodies, cascading lake systems, streams and rivers across the city. It is important going forward for Kolkata and other cities in West Bengal to be climate resilient looking at all the new infrastructure projects by being passed under the climate lens and have climate proofing in the attempt to achieve resilience,” said Anjal Prakash, climate scientist who is also one of the authors of the report.