MUMBAI: There may be a different kind of water crisis heading Mumbai’s way. Preliminary research on climate change suggests that the heavily populated coastal areas in Maharashtra, Goa and Gujarat are very vulnerable to inundation and flooding if sea levels rise due to global warming.

In Maharashtra, Mumbai will be most vulnerable because of the high reclamation and development along its coastline. If there is a one-metre rise in sea level over the next century, as some scientists predict, low-lying areas in the city—like the Back Bay and Versova—are in danger of being flooded or washed away, especially near mud-flats and creeks.

Detailed studies of the impact of climate change in India and Asia are almost absent, so current predictions are, at best, still highly speculative.

But according to one study by Tata Energy Research Institute, which ranked the vulnerability of different districts, the economic impact on Mumbai of a one-metre sea level rise would be over Rs 2,00,000 crore, mainly because of land and property loss.

Such predictions are based on the contention that average global temperatures are rising because of increasing atmospheric levels of gases like carbon dioxide, produced by the burning of fossil fuels. Sea levels are also rising, they say, because oceans expand as they become warmer but also because of the melting of polar glaciers.

In the 20th century, the sea level rose by 20 to 30 centimetres. The Inter-governmental Panel on Climate Change has projected another one metre rise by 2100, in a worst-case scenario.

Many scientists, while agreeing that temperatures have indeed risen, differ on the cause and the extent of effect. A.S. Unnikrishnan of the National Instiute of Oceanography (NIO), Goa, for example, says that while the data show a slight rise in sea levels over the years, this could also be due to geological changes like land sinking. But in the possible scenario that the ocean does come ashore, what impact can we expect?

Coastal infrastructure, tourist terrain and offshore oil exploration will be affected all along the west coast, the TERI study said. It estimates that Goa, with its huge coastline, will be worst hit, losing around four per cent of land.