Dumbbell effect will increase Mumbai’s troubles in monsoon, the effect of climate change

Very recently, we saw the extremely severe Cyclone Takte wreaking havoc in Mumbai , and now , the monsoon in Mumbai has thrown the city into disarray on the very first day of its arrival.

The Santa Cruz Observatory recorded 231 mm of rain in a span of 24 hours from 8:30 am on Wednesday . However , this is not unusual for Mumbai as the city receives triple digit rainfall every year during the monsoon season . But this time according to meteorologists , Mumbai Monsoon has a very special pattern and they have warned that there may be a flood-like situation in Mumbai.

According to GP Sharma , Retired AVM, Indian Air Force, Chairman, Department of Meteorology and Climate Change at Skymet Weather , “Due to the dumbbell effect , we can expect active Monsoon conditions from June 11 to June 15. The Western Branch of Monsoon over Arabian Sea will strengthen to affect the entire West Coast (Kerala , Karnataka , Goa , Konkan) with heavy rains and very heavy rain is expected over Mumbai between 09-16 June. There is a high probability of severe flood situation in and around Mumbai between June 13-15.

Sometimes , there is a simultaneous weather system in both the Arabian Sea and the Bay of Bengal. When the two systems complement each other to increase rainfall activity during the monsoon season, the dumbbell effect is born.

How climate change is affecting the weather

We saw Cyclone Tauta intensifying manifold due to normal sea surface temperatures in the Arabian Sea. In fact, as long as it was passing through Mumbai, as long as it had turned into a very severe cyclonic storm, which super cyclone was just one level down from. Atmospheric conditions were so mature that if the forward air and much more voyage, it also serves as a super cyclone.

Although we are not seeing a similar situation right now , but this time also global warming is definitely playing a major role. According to meteorologists, with the onset of monsoon, there is plenty of moisture available in the atmosphere. And , with sea ​​surface temperatures still very warm , it will continue to fuel intensification systems to form in the Indian basins.

Dr Roxy Mathew Cole, Climate Scientist , Indian Institute of Tropical Meteorology , Pune says , “ Ocean and atmospheric conditions are still very favorable for the intensification of weather systems. However, the cyclones has some cool sea surface, but the sea temperature is 30 ° C and hot with temperatures above. These warm sea surface temperatures and low vertical wind shear are favorable for the formation and intensification of a low pressure system over the northern Bay of Bengal , but they are not conducive to a cyclonic storm. The Arabian Sea is also warm and moist , so monsoon winds can carry more moisture as it pulls inland and strengthens in response to the low pressure system in the Gulf. Our research shows that there is an increasing trend of such events resulting in heavy rainfall over the west coast and central India.

threat to coastal cities

As tropical cyclones are increasing in coastal India due to climate change , unplanned development adds to the vulnerability of these cities. For example, over the past decade has resulted in economic losses of $ 3 billion by the floods in India – flooding nearly 10% of global economic losses. Cyclone Amphan affected 13 million people in 2020 and caused over $ 13 billion in damages after it made landfall in West Bengal .

Several studies claim that India’s largest coastal cities , such as Mumbai and Kolkata , face the most severe threats from climate-induced flooding. The floods in Mumbai and Kolkata have been attributed to the impact of climate change , urbanisation , sea ​​level rise and other regional factors.

According to a report by the Ministry of Earth Sciences (MoES), Government of India, assessment of climate change in the region, the Mumbai region is highly vulnerable to climate change due to rising sea level, storm surge and heavy rain. During the last 20 years , Mumbai has already witnessed massive flood incidents in 2005, 2014, 2017 .

The Mumbai floods in 2005 received 994 mm of rain in just 24 hours and 684 mm of rain in just 12 hours. Due to the rain, there was a severe flood in the Mithi river. The impact was further exacerbated by high tides and inadequate drainage and sewage resulting in widespread flooding.

Planned and unplanned development in most ecologically sensitive areas in these cities tends to bypass questions of politics , power and distributional conflicts that shape urban development, failing to address climate-change-related flood risks. is. Mumbai has witnessed a phenomenal growth in the last few decades by systematically building on mangrove forests. Mangroves are swamp forests that provide many ecosystem services to coastal communities. The density of trees , along with the diversity of tree species , reduces water runoff and creates a buffer zone of sorts against floods and storms.

A recent study by the Council for Energy Environment and Water (CEEW) states that more than 80 percent of Maharashtra’s districts are vulnerable to drought or drought-like conditions. Districts like Aurangabad , Jalna , Latur , Osamabad , Pune , Nashik and Nanded are drought hotspots in the state. On the other hand , it is quite clear that traditionally drought-prone districts have shown a shift towards extreme flood events and storm surges over the past decade. Additionally , the frequency of severe flood events in Maharashtra has increased six-fold in the last 50 years. These trends are a clear indicator of how climate unpredictability is increasing , making risk assessment a major challenge , with complex disasters and hazards increasing.

The economic cost of climate change: devastating floods in Mumbai

Greater Mumbai is home to over 20 million people and is one of the most densely populated cities in the world. It is the financial capital of India with a large commercial and trading base. However , most of the coastal cities are located less than 15 meters above sea level and about a quarter below sea level or at mean sea level. It is therefore one of the world’s most vulnerable port cities, facing a wide range of climate-related risks, including hurricanes , floods , coastal erosion and sea level rise.

Climate change is certainly not the only driver of environmental risk in Mumbai. The city was originally built on a series of islands hugging the coast. However , its lakes , rivers , muds , wetlands , mangroves , forests and beaches have been built to serve the gradually growing population and economy. The increase in hard surfaces and loss of tree cover have prevented precipitation from seeping into groundwater. Instead , it moves rapidly on asphalt and concrete , accumulating in the low-lying areas of the city rather than flowing into the sea . Poor sewage and drainage systems increase the health risks of flooding , including diseases such as malaria , diarrhea and leptospirosis.

Mumbai is already facing devastating floods and the city ranks fifth in the world with an annual loss of $ 284 million, according to a new review by the global think tank , ODI . In July 2005 , floods killed 5,000 people and caused a total of $690 million in economic damage. Floods will only worsen when combined with heavy rains , higher sea levels and more severe storms linked to climate change. In fact , experts have estimated that annual losses from floods will reach $ 6.1 billion per year in 2050 . Most of these losses are uninsured and are borne by individuals or small businesses.

Low-income rural communities, who depend on coastal ecosystems for food and livelihood, will be in the direct line of this fire because of the disappearance of coral reefs , erosion of mangroves and saline infiltration of water levels to agricultural land and natural ecosystems. hinders productivity.

Amir Bajaj, senior lead-practice at the Indian Institute for Human Settlements, says, “ Low income and other marginalized groups are most vulnerable to the effects of climate change as we see now with cyclone Taukte and Yas. . They often live in dense settlements that lack basic services and infrastructure that can reduce risk. Many homes also live on dangerous sites such as steep slopes and floodplains. That’s why it’s important to bring the climate and development goals together.”

The cost of inaction or delay in mitigation and adaptation will only increase the costs from climate change. This in turn acts as a dent on the plans for poverty alleviation and economic development.

Rathin Roy, Managing Director (Research and Policy) at ODI, said , “ Trailing a cleaner , more resource-efficient path to growth can lead to a faster , fairer economic recovery for India and help India in the long term. can help secure prosperity and competitiveness.Low carbon alternatives are more efficient and less polluting , providing immediate benefits such as cleaner air , greater energy security and faster job creation.

A survey conducted to understand the perception and awareness of climate risks for large , medium and small businesses in the state of Maharashtra found that large industries (78%) compared to MSMEs (68%) and more than 50% show a relatively strong acceptance of They believe climate change affects their region , and 45% believe it affects their business as well. Overall , heavy rainfall , floods , cyclones , water scarcity and rising temperatures were seen as the main threats to climate change across industries and regions. More than 400 businesses in different sectors were surveyed and 37% of businesses claimed that climate change resulted in “capital destruction” and “destruction of flora and fauna that is causing business losses”.