Mumbai, Kolkata, Chennai May Be Submerged By 2050

In late October 2019, the journal Nature Communications published the results of a study led by scientists Scott A. Kulp and Benjamin H. Strauss of Climate Central, an independent organisation of scientists, journalists and researchers working on climate breakdown.

 

The key messages of the study at the global level were:

·      As a result of heat-trapping pollution from human activities, rising sea levels could within three decades push chronic floods higher than land currently home to 300 million people.

·      By 2100, areas now home to 200 million people could fall permanently below the high tide line.

·      The threat is concentrated in coastal Asia and could have profound economic and political consequences within the lifetimes of people alive today.

The new figures are the result of an improved global elevation dataset produced by Climate Central using machine learning, which reveals that coastal elevations are significantly lower than previously understood across wide areas.

 

Global sea levels have risen by 11-16 cm or half the height of a 500 ml coke bottle in the 20th century, compared to the pre-industrial era, generally taken to be the year 1850. Even if the world drastically cuts down its annual carbon emissions, sea levels would rise half a metre by 2050 or roughly the height of two 500 ml coke bottles stacked up. In the most extreme scenario the sea level would rise 2 m by the turn of the century, or equivalent to the height of nearly nine such bottles stacked on top of each other.

As many as 70% of those living in low-lying areas are in eight Asian countries: China, India, Bangladesh, Vietnam, Indonesia, Thailand, the Philippines and Japan. The number of people already living in areas below high-tide line suggests that it is possible to defend a very large number of people but it would get increasingly expensive to do so, said scientists.

Globally, around 110 million people are already living in areas below high-tide levels; in India this number stands at 17 million. That would suggest that there are sea walls in various places that would allow habitation of certain neighbourhoods that would otherwise be below the high tide line. However, when it rains in these areas, the water has a hard time getting out.

Many of the island nations most affected by sea level rise have contributed negligible amounts to global carbon emissions and are already on their way to becoming carbon neutral. But large amounts of carbon already released into the atmosphere means that, even if we went carbon neutral today, there will still be substantial dangers to coastal populations.

 

Implications for India

India has a 7,500-km coastline and the second largest coastal population at risk due to sea level rise after China’s current 81 million. By 2050, 35 million Indians living in coastal areas could face the risk of annual flooding. By the turn of the century, this number could go up to 51 million if global carbon emissions continue unabated. Parts of Mumbai, Surat, Chennai and Kolkata will be either underwater or ravaged by recurring floods by 2050 as sea levels across the world will continue to rise with increasing carbon emissions. The coastal areas of Odisha and the north-east will be inundated by mid-century.

Across India, an estimated 31 million people live in coastal areas at risk of annual flooding, a number that could go up to 35 million by mid-century and rise further to 51 million by the year 2100. These projections are based on extreme-case scenarios if global carbon emissions continue to rise unabated. At the moment, 250 million people around the globe live in areas at risk of annual coastal floods.

The study did not take into account flooding due to erratic monsoons in India but scientists said that it could push up the numbers of those likely to be affected by flooding. Climate change has already led to undocumented internal migration Odisha and West Bengal. With large parts of Bangladesh set to become more saline or be inundated, international migration is also set to rise.

Source: https://www.indiaspend.com/mumbai-kolkata-chennai-may-be-submerged-by-2050-latest-data/